{
 "instance": {
  "es-20211231.htm": {
   "axisCustom": 1,
   "axisStandard": 52,
   "contextCount": 1534,
   "dts": {
    "calculationLink": {
     "local": [
      "es-20211231_cal.xml"
     ]
    },
    "definitionLink": {
     "local": [
      "es-20211231_def.xml"
     ]
    },
    "inline": {
     "local": [
      "es-20211231.htm"
     ]
    },
    "labelLink": {
     "local": [
      "es-20211231_lab.xml"
     ]
    },
    "presentationLink": {
     "local": [
      "es-20211231_pre.xml"
     ]
    },
    "schema": {
     "local": [
      "es-20211231.xsd"
     ],
     "remote": [
      "http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd",
      "http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd",
      "http://www.xbrl.org/2003/xl-2003-12-31.xsd",
      "http://www.xbrl.org/2003/xlink-2003-12-31.xsd",
      "http://www.xbrl.org/2005/xbrldt-2005.xsd",
      "http://www.xbrl.org/2006/ref-2006-02-27.xsd",
      "http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd",
      "http://www.xbrl.org/lrr/role/net-2009-12-16.xsd",
      "http://www.xbrl.org/lrr/role/reference-2009-12-16.xsd",
      "https://www.xbrl.org/2020/extensible-enumerations-2.0.xsd",
      "https://www.xbrl.org/dtr/type/2020-01-21/types.xsd",
      "https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd",
      "https://xbrl.fasb.org/srt/2021/elts/srt-roles-2021-01-31.xsd",
      "https://xbrl.fasb.org/srt/2021/elts/srt-types-2021-01-31.xsd",
      "https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd",
      "https://xbrl.fasb.org/us-gaap/2021/elts/us-roles-2021-01-31.xsd",
      "https://xbrl.fasb.org/us-gaap/2021/elts/us-types-2021-01-31.xsd",
      "https://xbrl.sec.gov/country/2021/country-2021.xsd",
      "https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd"
     ]
    }
   },
   "elementCount": 1312,
   "entityCount": 1,
   "hidden": {
    "http://fasb.org/us-gaap/2021-01-31": 16,
    "http://xbrl.sec.gov/dei/2021q4": 7,
    "total": 23
   },
   "keyCustom": 174,
   "keyStandard": 652,
   "memberCustom": 203,
   "memberStandard": 78,
   "nsprefix": "es",
   "nsuri": "http://www.eversource.com/20211231",
   "report": {
    "R1": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:DocumentType",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "document",
     "isDefault": "true",
     "longName": "000010001 - Document - COVER PAGE",
     "role": "http://www.eversource.com/role/COVERPAGE",
     "shortName": "COVER PAGE",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:DocumentType",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R10": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Cash",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100080010 - Statement - THE CONNECTICUT LIGHT AND POWER COMPANY BALANCE SHEETS",
     "role": "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS",
     "shortName": "THE CONNECTICUT LIGHT AND POWER COMPANY BALANCE SHEETS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "id3456111181f4211876889c4a264c60f_I20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:AccountsReceivableNetCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R100": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EquitySecuritiesFvNi",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240334022 - Disclosure - MARKETABLE SECURITIES - Equity Securities (Details)",
     "role": "http://www.eversource.com/role/MARKETABLESECURITIESEquitySecuritiesDetails",
     "shortName": "MARKETABLE SECURITIES - Equity Securities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EquitySecuritiesFvNi",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R101": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:InvestmentsClassifiedByContractualMaturityDateTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240344023 - Disclosure - MARKETABLE SECURITIES - Available-for-Sale Debt Securities (Details)",
     "role": "http://www.eversource.com/role/MARKETABLESECURITIESAvailableforSaleDebtSecuritiesDetails",
     "shortName": "MARKETABLE SECURITIES - Available-for-Sale Debt Securities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R102": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:InvestmentsClassifiedByContractualMaturityDateTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240354024 - Disclosure - MARKETABLE SECURITIES - Contractual Maturity (Details)",
     "role": "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails",
     "shortName": "MARKETABLE SECURITIES - Contractual Maturity (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:InvestmentsClassifiedByContractualMaturityDateTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R103": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentsFairValueDisclosure",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240364025 - Disclosure - MARKETABLE SECURITIES - Fair Value Measurement (Details)",
     "role": "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails",
     "shortName": "MARKETABLE SECURITIES - Fair Value Measurement (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentsFairValueDisclosure",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R104": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EquityMethodInvestments",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240394026 - Disclosure - INVESTMENTS IN UNCONSOLIDATED AFFILIATES - Summary of Investments (Details)",
     "role": "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESSummaryofInvestmentsDetails",
     "shortName": "INVESTMENTS IN UNCONSOLIDATED AFFILIATES - Summary of Investments (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i445640925e364d05b2f1c1a1b064775c_I20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:EquityMethodInvestments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R105": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeLossFromEquityMethodInvestments",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240404027 - Disclosure - INVESTMENTS IN UNCONSOLIDATED AFFILIATES - Narrative (Details)",
     "role": "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails",
     "shortName": "INVESTMENTS IN UNCONSOLIDATED AFFILIATES - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:EquityMethodInvestmentDividendsOrDistributions",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R106": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfChangeInAssetRetirementObligationTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ifd35200350fd4700b14552ef695feeb3_I20201231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AssetRetirementObligation",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240434028 - Disclosure - ASSET RETIREMENT OBLIGATIONS - Schedule of Reconciliation of Beginning and Ending Balance (Details)",
     "role": "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails",
     "shortName": "ASSET RETIREMENT OBLIGATIONS - Schedule of Reconciliation of Beginning and Ending Balance (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfChangeInAssetRetirementObligationTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "es:AssetRetirementObligationLiabilitiesAssumedInBusinessCombination",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R107": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfChangeInAssetRetirementObligationTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AssetRetirementObligation",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240444029 - Disclosure - ASSET RETIREMENT OBLIGATIONS - Narrative (Details)",
     "role": "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSNarrativeDetails",
     "shortName": "ASSET RETIREMENT OBLIGATIONS - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ied480d0f69224cbc8447d529e7f0d688_I20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:AssetRetirementObligation",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R108": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "if232157c55814865b1d08ec31f92cfd2_I20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240474030 - Disclosure - SHORT-TERM DEBT - Narrative (Details)",
     "role": "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails",
     "shortName": "SHORT-TERM DEBT - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "if232157c55814865b1d08ec31f92cfd2_I20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R109": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NotesPayable",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240484031 - Disclosure - SHORT-TERM DEBT - Schedule of Debt (Details)",
     "role": "http://www.eversource.com/role/SHORTTERMDEBTScheduleofDebtDetails",
     "shortName": "SHORT-TERM DEBT - Schedule of Debt (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfDebtTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "if232157c55814865b1d08ec31f92cfd2_I20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:NotesPayable",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R11": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllowanceForDoubtfulAccountsReceivable",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100090011 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)",
     "role": "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETSParenthetical_1",
     "shortName": "CONSOLIDATED BALANCE SHEETS (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": null
    },
    "R110": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LongTermDebtNoncurrent",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240514032 - Disclosure - LONG-TERM DEBT - Schedule of Long-Term Debt Outstanding (Details)",
     "role": "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
     "shortName": "LONG-TERM DEBT - Schedule of Long-Term Debt Outstanding (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "icef69ddc8e224523a63ae6c25e9864f5_I20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:DebtInstrumentUnamortizedDiscountPremiumNet",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R111": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RepaymentsOfLongTermDebt",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240524033 - Disclosure - LONG-TERM DEBT - Schedule of Issuances and Repayments (Details)",
     "role": "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
     "shortName": "LONG-TERM DEBT - Schedule of Issuances and Repayments (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i31fdcf79b5ec440b97ccf3f8fa13ac5b_I20210930",
      "decimals": "INF",
      "lang": "en-US",
      "name": "us-gaap:DebtInstrumentInterestRateStatedPercentage",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R112": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LongTermDebtNoncurrent",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240534034 - Disclosure - LONG-TERM DEBT - Narrative (Details)",
     "role": "http://www.eversource.com/role/LONGTERMDEBTNarrativeDetails",
     "shortName": "LONG-TERM DEBT - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ifd35200350fd4700b14552ef695feeb3_I20201231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "es:InterestIncludedInPaymentToSettleSpentNuclearFuelObligation",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R113": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240544035 - Disclosure - LONG-TERM DEBT - Schedule of Long-term Debt Maturities (Details)",
     "role": "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails",
     "shortName": "LONG-TERM DEBT - Schedule of Long-term Debt Maturities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R114": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i322fac4795a149fda889d392ef11ebf4_I20180508",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DebtInstrumentFaceAmount",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240574036 - Disclosure - RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES - Narrative (Details)",
     "role": "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESNarrativeDetails",
     "shortName": "RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i322fac4795a149fda889d392ef11ebf4_I20180508",
      "decimals": "4",
      "lang": "en-US",
      "name": "us-gaap:DebtWeightedAverageInterestRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R115": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RegulatoryAssets",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240584037 - Disclosure - RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES - Balance Sheet (Details)",
     "role": "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
     "shortName": "RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES - Balance Sheet (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i2f7e7a982678464cb9ea941b3dc44b5f_I20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "es:RateReductionBondsCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R116": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InterestExpense",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240594038 - Disclosure - RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES - Income Statement (Details)",
     "role": "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESIncomeStatementDetails",
     "shortName": "RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES - Income Statement (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i9007b58e5bc248e08062067a4d4ab662_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:AmortizationOfRegulatoryAsset",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R117": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "es:ScheduleOfRateReductionBondsPrincipalAndInterestPaymentsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "es:RateReductionBondsPrincipalAndInterestPaymentsToBePaidYearOne",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240604039 - Disclosure - RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES- Rate Reduction Bonds, Principal and Interest Payments (Details)",
     "role": "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails",
     "shortName": "RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES- Rate Reduction Bonds, Principal and Interest Payments (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "es:ScheduleOfRateReductionBondsPrincipalAndInterestPaymentsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "es:RateReductionBondsPrincipalAndInterestPaymentsToBePaidYearOne",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R118": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i29e657b073314c0fafef92af00e5a1f9_I20201231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanBenefitObligation",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240634040 - Disclosure - EMPLOYEE BENEFITS - Schedule of Pension Benefit Obligations (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails",
     "shortName": "EMPLOYEE BENEFITS - Schedule of Pension Benefit Obligations (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i4e5be8488b9944d8b8a4ff4d5ed02617_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanActuarialGainLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R119": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240644041 - Disclosure - EMPLOYEE BENEFITS - Pension Plan Narrative (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
     "shortName": "EMPLOYEE BENEFITS - Pension Plan Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i4e5be8488b9944d8b8a4ff4d5ed02617_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "es:DefinedBenefitPlanImpactonLiabilityasaResultofChangeinDiscountRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R12": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Revenues",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100100012 - Statement - THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF INCOME",
     "role": "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME",
     "shortName": "THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF INCOME",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ic536910a587e44b98dedee9506f97b6b_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "es:UtilitiesOperatingExpensePurchasedPowerPurchasedTransmissionAndFuelUsed",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R120": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfDefinedBenefitPlansDisclosuresTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i036cd6395b8848b9828f229c7325ad9a_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240654042 - Disclosure - EMPLOYEE BENEFITS - Schedule of Funded Status (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofFundedStatusDetails",
     "shortName": "EMPLOYEE BENEFITS - Schedule of Funded Status (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfDefinedBenefitPlansDisclosuresTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i036cd6395b8848b9828f229c7325ad9a_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R121": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfAssumptionsUsedTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i8220b79772b84d5db432bbad538490d7_I20211231",
      "decimals": "4",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240664043 - Disclosure - EMPLOYEE BENEFITS - Schedule of Actuarial Assumptions (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails",
     "shortName": "EMPLOYEE BENEFITS - Schedule of Actuarial Assumptions (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfAssumptionsUsedTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i8220b79772b84d5db432bbad538490d7_I20211231",
      "decimals": "4",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R122": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i4e5be8488b9944d8b8a4ff4d5ed02617_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanServiceCost",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240674044 - Disclosure - EMPLOYEE BENEFITS - Schedule of Components of Net Periodic Benefit Costs (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails",
     "shortName": "EMPLOYEE BENEFITS - Schedule of Components of Net Periodic Benefit Costs (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfNetBenefitCostsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i4e5be8488b9944d8b8a4ff4d5ed02617_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R123": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets",
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets",
      "reportCount": 1,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240684045 - Disclosure - EMPLOYEE BENEFITS - Schedule of Assumptions used To Calculate Pension and SERP and PBOP (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssumptionsusedToCalculatePensionandSERPandPBOPDetails",
     "shortName": "EMPLOYEE BENEFITS - Schedule of Assumptions used To Calculate Pension and SERP and PBOP (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ib7407e0d10bc47febca637ac0f4e5cd3_D20210101-20211231",
      "decimals": "4",
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R124": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfAmountsRecognizedInOtherComprehensiveIncomeLossTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i036cd6395b8848b9828f229c7325ad9a_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "es:GainLossArisingDuringYearRegulatoryAsset",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240694046 - Disclosure - EMPLOYEE BENEFITS - Summary of Changes in Plan Assets and Benefit Obligations (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails",
     "shortName": "EMPLOYEE BENEFITS - Summary of Changes in Plan Assets and Benefit Obligations (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfAmountsRecognizedInOtherComprehensiveIncomeLossTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i036cd6395b8848b9828f229c7325ad9a_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "es:GainLossArisingDuringYearRegulatoryAsset",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R125": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i036cd6395b8848b9828f229c7325ad9a_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240704047 - Disclosure - EMPLOYEE BENEFITS - Schedule of Estimated Future Benefit Payments (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofEstimatedFutureBenefitPaymentsDetails",
     "shortName": "EMPLOYEE BENEFITS - Schedule of Estimated Future Benefit Payments (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i036cd6395b8848b9828f229c7325ad9a_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R126": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfAllocationOfPlanAssetsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i8bb7c5f70b44482f8331502524a08d65_I20211231",
      "decimals": "3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240714048 - Disclosure - EMPLOYEE BENEFITS - Schedule of Long-term Rates of Return on Pension and PBOP (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails",
     "shortName": "EMPLOYEE BENEFITS - Schedule of Long-term Rates of Return on Pension and PBOP (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfAllocationOfPlanAssetsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i8bb7c5f70b44482f8331502524a08d65_I20211231",
      "decimals": "3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R127": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i036cd6395b8848b9828f229c7325ad9a_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedBenefitPlanFairValueOfPlanAssets",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240724049 - Disclosure - EMPLOYEE BENEFITS - Schedule of Asset Category (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
     "shortName": "EMPLOYEE BENEFITS - Schedule of Asset Category (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfAllocationOfPlanAssetsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i036cd6395b8848b9828f229c7325ad9a_I20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "es:DefinedBenefitPlanFairValueofPlanAssetsUncategorized",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R128": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i2b9807a51d32413696b96fb8a1712177_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedContributionPlanEmployerMatchingContributionPercentOfMatch",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240734050 - Disclosure - EMPLOYEE BENEFITS - Defined Contribution Plan Narrative (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSDefinedContributionPlanNarrativeDetails",
     "shortName": "EMPLOYEE BENEFITS - Defined Contribution Plan Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i2b9807a51d32413696b96fb8a1712177_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedContributionPlanEmployerMatchingContributionPercentOfMatch",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R129": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "es:ScheduleOfDefinedContributionPlans401kTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedContributionPlanCostRecognized",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240744051 - Disclosure - EMPLOYEE BENEFITS - Schedule of Defined Contribution Plans (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofDefinedContributionPlansDetails",
     "shortName": "EMPLOYEE BENEFITS - Schedule of Defined Contribution Plans (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "es:ScheduleOfDefinedContributionPlans401kTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedContributionPlanCostRecognized",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R13": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100110013 - Statement - THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF COMPREHENSIVE INCOME",
     "role": "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMPREHENSIVEINCOME",
     "shortName": "THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF COMPREHENSIVE INCOME",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ic536910a587e44b98dedee9506f97b6b_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R130": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240754052 - Disclosure - EMPLOYEE BENEFITS - Share-Based Payments Narrative (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails",
     "shortName": "EMPLOYEE BENEFITS - Share-Based Payments Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R131": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ie6913520b5d941e78e09e84e0ac9eedd_I20201231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "es:SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsNonvestedandVestedNumber",
      "reportCount": 1,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240764053 - Disclosure - EMPLOYEE BENEFITS - Summary of RSU and Share Transactions (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails",
     "shortName": "EMPLOYEE BENEFITS - Summary of RSU and Share Transactions (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "iae0fa410e93844d28c5f7828078ea5b2_D20210101-20211231",
      "decimals": "INF",
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R132": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllocatedShareBasedCompensationExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240774054 - Disclosure - EMPLOYEE BENEFITS - Schedule of Compensation Expense and Income Tax Benefit (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofCompensationExpenseandIncomeTaxBenefitDetails",
     "shortName": "EMPLOYEE BENEFITS - Schedule of Compensation Expense and Income Tax Benefit (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllocatedShareBasedCompensationExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R133": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DeferredCompensationCashbasedArrangementsLiabilityClassifiedNoncurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240784055 - Disclosure - EMPLOYEE BENEFITS - Schedule of Other Retirement Benefits (Details)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofOtherRetirementBenefitsDetails",
     "shortName": "EMPLOYEE BENEFITS - Schedule of Other Retirement Benefits (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DeferredCompensationCashbasedArrangementsLiabilityClassifiedNoncurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R134": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CurrentFederalTaxExpenseBenefit",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240814056 - Disclosure - INCOME TAXES - Components of Income Tax Expense (Details)",
     "role": "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails",
     "shortName": "INCOME TAXES - Components of Income Tax Expense (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CurrentFederalTaxExpenseBenefit",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R135": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240824057 - Disclosure - INCOME TAXES - Reconciliation Between Income Tax Expense and Expected Tax Expense (Details)",
     "role": "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails",
     "shortName": "INCOME TAXES - Reconciliation Between Income Tax Expense and Expected Tax Expense (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R136": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240834058 - Disclosure - INCOME TAXES - Temporary Differences That Give Rise To Accumulated Deferred Income Tax Obligations (Details)",
     "role": "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails",
     "shortName": "INCOME TAXES - Temporary Differences That Give Rise To Accumulated Deferred Income Tax Obligations (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R137": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i983c42d9d354477889b4f1e657952725_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:TaxCreditCarryforwardAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240844059 - Disclosure - INCOME TAXES - Tax Credits and Loss Carryforwards (Details)",
     "role": "http://www.eversource.com/role/INCOMETAXESTaxCreditsandLossCarryforwardsDetails",
     "shortName": "INCOME TAXES - Tax Credits and Loss Carryforwards (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i983c42d9d354477889b4f1e657952725_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:TaxCreditCarryforwardAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R138": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "es:SocialSecurityTaxEmployerDeferralCARESAct",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240854060 - Disclosure - INCOME TAXES - Narrative (Details)",
     "role": "http://www.eversource.com/role/INCOMETAXESNarrativeDetails",
     "shortName": "INCOME TAXES - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "es:SocialSecurityTaxEmployerDeferralCARESAct",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R139": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ifd35200350fd4700b14552ef695feeb3_I20201231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:UnrecognizedTaxBenefits",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240864061 - Disclosure - INCOME TAXES - Reconciliation of Unrecognized Tax Benefit (Details)",
     "role": "http://www.eversource.com/role/INCOMETAXESReconciliationofUnrecognizedTaxBenefitDetails",
     "shortName": "INCOME TAXES - Reconciliation of Unrecognized Tax Benefit (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i13fbe426fb6c478c835158a58c8aecd5_I20181231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:UnrecognizedTaxBenefits",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R14": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i70af593ab79b4177a1b6e37163fae22c_I20181231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommonStockSharesOutstanding",
      "reportCount": 1,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100120014 - Statement - THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF COMMON STOCKHOLDER'S EQUITY",
     "role": "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
     "shortName": "THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF COMMON STOCKHOLDER'S EQUITY",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i3b794e992f9043bea6566ac0e53ac93d_I20181231",
      "decimals": "INF",
      "lang": "en-US",
      "name": "us-gaap:CommonStockSharesOutstanding",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R140": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ifd35200350fd4700b14552ef695feeb3_I20201231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AccrualForEnvironmentalLossContingencies",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240894062 - Disclosure - COMMITMENTS AND CONTINGENCIES - Schedule of Reconciliation of Activity in Environmental Reserve (Details)",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofReconciliationofActivityinEnvironmentalReserveDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - Schedule of Reconciliation of Activity in Environmental Reserve (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i593c0663fa7946c3a11745aeabb12f16_D20200101-20201231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForAcquisitionsAndDivestitures",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R141": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "es:EnvironmentalSiteQuantity",
      "reportCount": 1,
      "unitRef": "site",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240904063 - Disclosure - COMMITMENTS AND CONTINGENCIES - Schedule of Number of Sites and Reserves (Details)",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofNumberofSitesandReservesDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - Schedule of Number of Sites and Reserves (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R142": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "es:EnvironmentalSiteQuantity",
      "reportCount": 1,
      "unitRef": "site",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240914064 - Disclosure - COMMITMENTS AND CONTINGENCIES - Environmental Matters Narrative (Details)",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - Environmental Matters Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "iddc43d491c0e45ffaeac308991e74ce9_I20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:AccrualForEnvironmentalLossContingenciesComponentAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R143": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240924065 - Disclosure - COMMITMENTS AND CONTINGENCIES - Schedule of Estimated Future Annual Costs of Long term Contractual Agreement (Details)",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - Schedule of Estimated Future Annual Costs of Long term Contractual Agreement (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R144": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240934066 - Disclosure - COMMITMENTS AND CONTINGENCIES - Long-Term Contractual Arrangement Narrative (Details)",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - Long-Term Contractual Arrangement Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "lang": "en-US",
      "name": "es:ContractualObligationTermOfContract",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R145": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "es:RenewableEnergyCostsIncurred",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240944067 - Disclosure - COMMITMENTS AND CONTINGENCIES - Schedule of Total Costs Incurred (Details)",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofTotalCostsIncurredDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - Schedule of Total Costs Incurred (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "es:RenewableEnergyCostsIncurred",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R146": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i5da5d1c4a3894be2bcc3dd5fc445b537_D20190612-20190612",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LossContingencyDamagesAwardedValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240954068 - Disclosure - COMMITMENTS AND CONTINGENCIES - Spent Nuclear Fuel Obligations Narrative (Details)",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - Spent Nuclear Fuel Obligations Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i5da5d1c4a3894be2bcc3dd5fc445b537_D20190612-20190612",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LossContingencyDamagesAwardedValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R147": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:GuaranteeObligationsCurrentCarryingValue",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240964069 - Disclosure - COMMITMENTS AND CONTINGENCIES - Schedule of Guarantees and Indemnifications (Details)",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - Schedule of Guarantees and Indemnifications (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "us-gaap:ScheduleOfGuaranteeObligationsTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i2e50970b66024c4784fad101c9008a42_I20211231",
      "decimals": "2",
      "lang": "en-US",
      "name": "us-gaap:EquityMethodInvestmentOwnershipPercentage",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R148": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:GuaranteeObligationsCurrentCarryingValue",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240974070 - Disclosure - COMMITMENTS AND CONTINGENCIES - Guarantees and Obligations Narrative (Details)",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESGuaranteesandObligationsNarrativeDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - Guarantees and Obligations Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i674fc84f6bcb452bae63e6d0e534491d_I20200916",
      "decimals": "INF",
      "lang": "en-US",
      "name": "us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R149": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "idf41d5004cb447c489ad8c8300d7da09_D20181016-20181016",
      "decimals": "4",
      "first": true,
      "lang": "en-US",
      "name": "es:LossContingencyPercentageOfBaseROEReasonablyJustified",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240984071 - Disclosure - COMMITMENTS AND CONTINGENCIES - FERC ROE Complaints (Details)",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - FERC ROE Complaints (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "idf41d5004cb447c489ad8c8300d7da09_D20181016-20181016",
      "decimals": "4",
      "first": true,
      "lang": "en-US",
      "name": "es:LossContingencyPercentageOfBaseROEReasonablyJustified",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R15": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100130015 - Statement - THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF CASH FLOWS",
     "role": "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS",
     "shortName": "THE CONNECTICUT LIGHT AND POWER COMPANY STATEMENTS OF CASH FLOWS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ic536910a587e44b98dedee9506f97b6b_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:PensionAndOtherPostretirementBenefitExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R150": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i3dd1c17456904ab08d2be87b5ccecd77_D20160715-20160715",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "es:CapacityRequiredForInstallationofDistributionCable",
      "reportCount": 1,
      "unique": true,
      "unitRef": "kv",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240994072 - Disclosure - COMMITMENTS AND CONTINGENCIES - Eversource and NSTAR Electric Boston Harbor Civil Action (Details)",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEversourceandNSTARElectricBostonHarborCivilActionDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - Eversource and NSTAR Electric Boston Harbor Civil Action (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i3dd1c17456904ab08d2be87b5ccecd77_D20160715-20160715",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "es:CapacityRequiredForInstallationofDistributionCable",
      "reportCount": 1,
      "unique": true,
      "unitRef": "kv",
      "xsiNil": "false"
     }
    },
    "R151": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i33ed2b7293bc44259668263ef67b4216_I20210428",
      "decimals": "4",
      "first": true,
      "lang": "en-US",
      "name": "es:LossContingencyAllowedRateOfROE",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241004073 - Disclosure - COMMITMENTS AND CONTINGENCIES - CL&P Tropical Storm Isaias Response Investigation (Details)",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPTropicalStormIsaiasResponseInvestigationDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - CL&P Tropical Storm Isaias Response Investigation (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i33ed2b7293bc44259668263ef67b4216_I20210428",
      "decimals": "4",
      "first": true,
      "lang": "en-US",
      "name": "es:LossContingencyAllowedRateOfROE",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R152": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RegulatoryLiabilityCurrent",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241014074 - Disclosure - COMMITMENTS AND CONTINGENCIES - CL&P Comprehensive Settlement Agreement (Details)",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - CL&P Comprehensive Settlement Agreement (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i793c6913619a4a2dbcd8d11ee3dbad2f_D20211001-20211001",
      "decimals": "4",
      "lang": "en-US",
      "name": "es:LossContingencyBasisPointsReductionToReturnOnEquityScenarioOne",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R153": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "es:LesseeLeasesOtherInformationTableTextBlock",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241044075 - Disclosure - LEASES - Narrative (Details)",
     "role": "http://www.eversource.com/role/LEASESNarrativeDetails",
     "shortName": "LEASES - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i5f2781f7484b4fbd9ab77507d7f06ea5_D20200101-20201231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R154": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:LeaseCostTableTextBlock",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FinanceLeaseRightOfUseAssetAmortization",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241054076 - Disclosure - LEASES - Components of Lease Cost (Details)",
     "role": "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails",
     "shortName": "LEASES - Components of Lease Cost (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:LeaseCostTableTextBlock",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FinanceLeaseRightOfUseAssetAmortization",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R155": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "es:LesseeLeasesSupplementalBalanceSheetInformationTableTextBlock",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OperatingLeaseRightOfUseAsset",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241064077 - Disclosure - LEASES - Supplemental Balance Sheet Information Related to Leases (Details)",
     "role": "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails",
     "shortName": "LEASES - Supplemental Balance Sheet Information Related to Leases (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "es:LesseeLeasesSupplementalBalanceSheetInformationTableTextBlock",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OperatingLeaseRightOfUseAsset",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R156": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "es:LesseeLeasesOtherInformationTableTextBlock",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OperatingLeaseWeightedAverageRemainingLeaseTerm1",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241074078 - Disclosure - LEASES - Other Information Related to Leases (Details)",
     "role": "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails",
     "shortName": "LEASES - Other Information Related to Leases (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "es:LesseeLeasesOtherInformationTableTextBlock",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OperatingLeaseWeightedAverageRemainingLeaseTerm1",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R157": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:FinanceLeaseLiabilityMaturityTableTextBlock",
       "us-gaap:LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241084079 - Disclosure - LEASES - Future Minimum Lease Payments under Long-Term Leases (Details)",
     "role": "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails",
     "shortName": "LEASES - Future Minimum Lease Payments under Long-Term Leases (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:FinanceLeaseLiabilityMaturityTableTextBlock",
       "us-gaap:LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R158": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RedeemableNoncontrollingInterestEquityPreferredCarryingAmount",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241114080 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS - Fair Value Hierarchy (Details)",
     "role": "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails",
     "shortName": "FAIR VALUE OF FINANCIAL INSTRUMENTS - Fair Value Hierarchy (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "if269b72e21f2490882662294beb31e43_I20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:RedeemableNoncontrollingInterestEquityPreferredCarryingAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R159": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ifd35200350fd4700b14552ef695feeb3_I20201231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:StockholdersEquity",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241144081 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Schedule of Changes in AOCI By Component (Details)",
     "role": "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails",
     "shortName": "ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Schedule of Changes in AOCI By Component (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:OciBeforeReclassificationsBeforeTaxAttributableToParent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R16": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Cash",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100140016 - Statement - NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED BALANCE SHEETS",
     "role": "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
     "shortName": "NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED BALANCE SHEETS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "id420762f79d04928b13ddbc17cb3c796_I20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:AccountsReceivableNetCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R160": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeReclassificationAdjustmentsTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241154082 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Narrative (Details)",
     "role": "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSNarrativeDetails",
     "shortName": "ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeReclassificationAdjustmentsTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R161": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeTaxExpenseBenefit",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241164083 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Schedule of Amounts Reclassified From AOCI By Component (Details)",
     "role": "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails",
     "shortName": "ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Schedule of Amounts Reclassified From AOCI By Component (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfComprehensiveIncomeLossTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R162": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RatioOfIndebtednessToNetCapital1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241184084 - Disclosure - DIVIDEND RESTRICTIONS (Details)",
     "role": "http://www.eversource.com/role/DIVIDENDRESTRICTIONSDetails",
     "shortName": "DIVIDEND RESTRICTIONS (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RatioOfIndebtednessToNetCapital1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R163": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:CommonStockParOrStatedValuePerShare",
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfStockByClassTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommonStockParOrStatedValuePerShare",
      "reportCount": 1,
      "unitRef": "usdPerShare",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241214085 - Disclosure - COMMON SHARES - Common Shares Authorized and Issued (Details)",
     "role": "http://www.eversource.com/role/COMMONSHARESCommonSharesAuthorizedandIssuedDetails",
     "shortName": "COMMON SHARES - Common Shares Authorized and Issued (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:CommonStockSharesAuthorized",
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfStockByClassTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "INF",
      "lang": "en-US",
      "name": "us-gaap:CommonStockSharesAuthorized",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R164": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i06b07e8bdaa8401b8bf8efc8ca183b24_D20200615-20200615",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SaleOfStockNumberOfSharesIssuedInTransaction",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241224086 - Disclosure - COMMON SHARES - Narrative (Details)",
     "role": "http://www.eversource.com/role/COMMONSHARESNarrativeDetails",
     "shortName": "COMMON SHARES - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i06b07e8bdaa8401b8bf8efc8ca183b24_D20200615-20200615",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SaleOfStockNumberOfSharesIssuedInTransaction",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R165": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "id3456111181f4211876889c4a264c60f_I20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PreferredStockSharesAuthorized",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241254087 - Disclosure - PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION - Narrative (Details)",
     "role": "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONNarrativeDetails",
     "shortName": "PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "id3456111181f4211876889c4a264c60f_I20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PreferredStockSharesAuthorized",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R166": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PreferredStockValueOutstanding",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241264088 - Disclosure - PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION - Schedule of Preferred Stock by Class (Details)",
     "role": "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails",
     "shortName": "PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION - Schedule of Preferred Stock by Class (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PreferredStockValueOutstanding",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R167": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ProfitLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241284089 - Disclosure - COMMON SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS (Details)",
     "role": "http://www.eversource.com/role/COMMONSHAREHOLDERSEQUITYANDNONCONTROLLINGINTERESTSDetails",
     "shortName": "COMMON SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ProfitLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R168": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "0",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241314090 - Disclosure - EARNINGS PER SHARE - Narrative (Details)",
     "role": "http://www.eversource.com/role/EARNINGSPERSHARENarrativeDetails",
     "shortName": "EARNINGS PER SHARE - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "0",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R169": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241324091 - Disclosure - EARNINGS PER SHARE - Components of Basic and Diluted EPS (Details)",
     "role": "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails",
     "shortName": "EARNINGS PER SHARE - Components of Basic and Diluted EPS (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "0",
      "lang": "en-US",
      "name": "es:IncrementalCommonSharesAttributableToDilutiveEffectOfShareBasedPaymentArrangementsAndOther",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R17": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllowanceForDoubtfulAccountsReceivable",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100150017 - Statement - NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED BALANCE SHEETS (Parenthetical)",
     "role": "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETSParenthetical",
     "shortName": "NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED BALANCE SHEETS (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": null
    },
    "R170": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:DisaggregationOfRevenueTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241354092 - Disclosure - REVENUES - Operating Revenues Disaggregated by Revenue Source (Details)",
     "role": "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
     "shortName": "REVENUES - Operating Revenues Disaggregated by Revenue Source (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:DisaggregationOfRevenueTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:RevenueNotFromContractWithCustomer",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R171": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:GainLossRelatedToLitigationSettlement",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241364093 - Disclosure - REVENUES - Narrative (Details)",
     "role": "http://www.eversource.com/role/REVENUESNarrativeDetails",
     "shortName": "REVENUES - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:OperatingLeaseLeaseIncome",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R172": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NumberOfReportableSegments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "segment",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241394094 - Disclosure - SEGMENT INFORMATION - Narrative (Details)",
     "role": "http://www.eversource.com/role/SEGMENTINFORMATIONNarrativeDetails",
     "shortName": "SEGMENT INFORMATION - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NumberOfReportableSegments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "segment",
      "xsiNil": "false"
     }
    },
    "R173": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Revenues",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241404095 - Disclosure - SEGMENT INFORMATION - Schedule of Segment Information (Details)",
     "role": "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails",
     "shortName": "SEGMENT INFORMATION - Schedule of Segment Information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfSegmentReportingInformationBySegmentTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:DepreciationDepletionAndAmortization",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R174": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i593c0663fa7946c3a11745aeabb12f16_D20200101-20201231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BusinessAcquisitionsProFormaRevenue",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241434096 - Disclosure - ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS - Narrative (Details)",
     "role": "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails",
     "shortName": "ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i593c0663fa7946c3a11745aeabb12f16_D20200101-20201231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R175": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Goodwill",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241444097 - Disclosure - ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS - Preliminary Allocation of the Cash Purchase Price (Details)",
     "role": "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails",
     "shortName": "ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS - Preliminary Allocation of the Cash Purchase Price (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ie78a66f13b2441c4b29ac6d812584db4_I20201009",
      "decimals": "-6",
      "lang": "en-US",
      "name": "us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R176": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i593c0663fa7946c3a11745aeabb12f16_D20200101-20201231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BusinessAcquisitionsProFormaRevenue",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241454098 - Disclosure - ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS - Schedule of Pro Forma Information (Details)",
     "role": "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSScheduleofProFormaInformationDetails",
     "shortName": "ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS - Schedule of Pro Forma Information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i5f2781f7484b4fbd9ab77507d7f06ea5_D20200101-20201231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "us-gaap:BusinessAcquisitionsProFormaNetIncomeLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R177": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:GoodwillAcquiredDuringPeriod",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241484099 - Disclosure - GOODWILL - Narrative (Details)",
     "role": "http://www.eversource.com/role/GOODWILLNarrativeDetails",
     "shortName": "GOODWILL - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ifbb809f8b86b4e49be1b872b6c7abd14_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:GoodwillAcquiredDuringPeriod",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R178": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ifd35200350fd4700b14552ef695feeb3_I20201231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Goodwill",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241494100 - Disclosure - GOODWILL - Summary of Goodwill by Reportable Segment (Details)",
     "role": "http://www.eversource.com/role/GOODWILLSummaryofGoodwillbyReportableSegmentDetails",
     "shortName": "GOODWILL - Summary of Goodwill by Reportable Segment (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i179f035eb158428ea0d99af12b473c47_I20191231",
      "decimals": "-6",
      "lang": "en-US",
      "name": "us-gaap:Goodwill",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R179": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Cash",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241514101 - Disclosure - SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - BALANCE SHEET (Details)",
     "role": "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
     "shortName": "SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - BALANCE SHEET (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:CondensedFinancialInformationOfParentCompanyOnlyDisclosureTextBlock",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i3ab333911e0f400a9c03682328f73157_I20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:Cash",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R18": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Revenues",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100160018 - Statement - NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF INCOME",
     "role": "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
     "shortName": "NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF INCOME",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ic76115e3bf174e0f96337baccd4a0f0a_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "es:UtilitiesOperatingExpensePurchasedPowerPurchasedTransmissionAndFuelUsed",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R180": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Revenues",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241524102 - Disclosure - SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - STATEMENTS OF INCOME (Details)",
     "role": "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails",
     "shortName": "SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - STATEMENTS OF INCOME (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "if3e70bb80e8d4e3e892dffdeaa1a95f1_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:Revenues",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R181": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241534103 - Disclosure - SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - STATEMENTS OF COMPREHENSIVE INCOME (Details)",
     "role": "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFCOMPREHENSIVEINCOMEDetails",
     "shortName": "SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - STATEMENTS OF COMPREHENSIVE INCOME (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "if3e70bb80e8d4e3e892dffdeaa1a95f1_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R182": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241544104 - Disclosure - SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - STATEMENT OF CASH FLOW (Details)",
     "role": "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
     "shortName": "SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT - STATEMENT OF CASH FLOW (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "if3e70bb80e8d4e3e892dffdeaa1a95f1_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R183": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i593c0663fa7946c3a11745aeabb12f16_D20200101-20201231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "es:AccountsReceivableAllowanceForCreditLossIncreaseFromBusinessCombination",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "241564105 - Disclosure - SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (Details)",
     "role": "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails",
     "shortName": "SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "srt:ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "if79a43ab7ded472fb717f8485ee64b4b_I20181231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:ValuationAllowancesAndReservesBalance",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R19": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100170019 - Statement - NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME",
     "role": "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
     "shortName": "NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ic76115e3bf174e0f96337baccd4a0f0a_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R2": {
     "firstAnchor": {
      "ancestors": [
       "dei:AuditorFirmId",
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:AuditorFirmId",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "document",
     "isDefault": "false",
     "longName": "000020002 - Document - Audit Information",
     "role": "http://www.eversource.com/role/AuditInformation",
     "shortName": "Audit Information",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "dei:AuditorFirmId",
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:AuditorFirmId",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R20": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i70af593ab79b4177a1b6e37163fae22c_I20181231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommonStockSharesOutstanding",
      "reportCount": 1,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100180020 - Statement - NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDER'S EQUITY",
     "role": "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
     "shortName": "NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDER'S EQUITY",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ic7d59451d92e4310971a68d7631a3097_I20181231",
      "decimals": "INF",
      "lang": "en-US",
      "name": "us-gaap:CommonStockSharesOutstanding",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R21": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100190021 - Statement - NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF CASH FLOWS",
     "role": "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
     "shortName": "NSTAR ELECTRIC COMPANY AND SUBSIDIARY CONSOLIDATED STATEMENTS OF CASH FLOWS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ic76115e3bf174e0f96337baccd4a0f0a_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:PensionAndOtherPostretirementBenefitExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R22": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Cash",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100200022 - Statement - PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED BALANCE SHEETS",
     "role": "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
     "shortName": "PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED BALANCE SHEETS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i661a7c4f80f549868db0a558171d0ca8_I20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:AccountsReceivableNetCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R23": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllowanceForDoubtfulAccountsReceivable",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100210023 - Statement - PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED BALANCE SHEETS (Parenthetical)",
     "role": "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETSParenthetical",
     "shortName": "PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED BALANCE SHEETS (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": null
    },
    "R24": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Revenues",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100220024 - Statement - PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF INCOME",
     "role": "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
     "shortName": "PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF INCOME",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i2cc7b5f27753480a81fd7f02d3c92f25_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "es:UtilitiesOperatingExpensePurchasedPowerPurchasedTransmissionAndFuelUsed",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R25": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100230025 - Statement - PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME",
     "role": "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
     "shortName": "PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i2cc7b5f27753480a81fd7f02d3c92f25_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R26": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i70af593ab79b4177a1b6e37163fae22c_I20181231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommonStockSharesOutstanding",
      "reportCount": 1,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100240026 - Statement - PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDER'S EQUITY",
     "role": "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
     "shortName": "PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDER'S EQUITY",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ie3e45e8707354e76b0ff50fc31baab53_I20181231",
      "decimals": "INF",
      "lang": "en-US",
      "name": "us-gaap:CommonStockSharesOutstanding",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R27": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100250027 - Statement - PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF CASH FLOWS",
     "role": "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
     "shortName": "PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE AND SUBSIDIARIES CONSOLIDATED STATEMENTS OF CASH FLOWS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i2cc7b5f27753480a81fd7f02d3c92f25_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:PensionAndOtherPostretirementBenefitExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R28": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SignificantAccountingPoliciesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210011001 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES",
     "role": "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES",
     "shortName": "SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SignificantAccountingPoliciesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R29": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PublicUtilitiesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210141002 - Disclosure - REGULATORY ACCOUNTING",
     "role": "http://www.eversource.com/role/REGULATORYACCOUNTING",
     "shortName": "REGULATORY ACCOUNTING",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PublicUtilitiesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R3": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Cash",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100010003 - Statement - CONSOLIDATED BALANCE SHEETS",
     "role": "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
     "shortName": "CONSOLIDATED BALANCE SHEETS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:MarketableSecuritiesNoncurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R30": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210191003 - Disclosure - PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION",
     "role": "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATION",
     "shortName": "PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R31": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210251004 - Disclosure - DERIVATIVE INSTRUMENTS",
     "role": "http://www.eversource.com/role/DERIVATIVEINSTRUMENTS",
     "shortName": "DERIVATIVE INSTRUMENTS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R32": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210311005 - Disclosure - MARKETABLE SECURITIES",
     "role": "http://www.eversource.com/role/MARKETABLESECURITIES",
     "shortName": "MARKETABLE SECURITIES",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R33": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EquityMethodInvestmentsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210371006 - Disclosure - INVESTMENTS IN UNCONSOLIDATED AFFILIATES",
     "role": "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATES",
     "shortName": "INVESTMENTS IN UNCONSOLIDATED AFFILIATES",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EquityMethodInvestmentsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R34": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AssetRetirementObligationDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210411007 - Disclosure - ASSET RETIREMENT OBLIGATIONS",
     "role": "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONS",
     "shortName": "ASSET RETIREMENT OBLIGATIONS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AssetRetirementObligationDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R35": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ShortTermDebtTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210451008 - Disclosure - SHORT-TERM DEBT",
     "role": "http://www.eversource.com/role/SHORTTERMDEBT",
     "shortName": "SHORT-TERM DEBT",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ShortTermDebtTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R36": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LongTermDebtTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210491009 - Disclosure - LONG-TERM DEBT",
     "role": "http://www.eversource.com/role/LONGTERMDEBT",
     "shortName": "LONG-TERM DEBT",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LongTermDebtTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R37": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "es:RateReductionBondsandVariableInterestEntityDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210551010 - Disclosure - RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES",
     "role": "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIES",
     "shortName": "RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "es:RateReductionBondsandVariableInterestEntityDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R38": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CompensationAndEmployeeBenefitPlansTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210611011 - Disclosure - EMPLOYEE BENEFITS",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITS",
     "shortName": "EMPLOYEE BENEFITS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CompensationAndEmployeeBenefitPlansTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R39": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeTaxDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210791012 - Disclosure - INCOME TAXES",
     "role": "http://www.eversource.com/role/INCOMETAXES",
     "shortName": "INCOME TAXES",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeTaxDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R4": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllowanceForDoubtfulAccountsReceivable",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100020004 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)",
     "role": "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETSParenthetical",
     "shortName": "CONSOLIDATED BALANCE SHEETS (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": null
    },
    "R40": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "210871013 - Disclosure - COMMITMENTS AND CONTINGENCIES",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIES",
     "shortName": "COMMITMENTS AND CONTINGENCIES",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R41": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LesseeOperatingLeasesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211021014 - Disclosure - LEASES",
     "role": "http://www.eversource.com/role/LEASES",
     "shortName": "LEASES",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LesseeOperatingLeasesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R42": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211091015 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS",
     "role": "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTS",
     "shortName": "FAIR VALUE OF FINANCIAL INSTRUMENTS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R43": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ComprehensiveIncomeNoteTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211121016 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS)",
     "role": "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSS",
     "shortName": "ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS)",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ComprehensiveIncomeNoteTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R44": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfDividendPaymentRestrictionsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211171017 - Disclosure - DIVIDEND RESTRICTIONS",
     "role": "http://www.eversource.com/role/DIVIDENDRESTRICTIONS",
     "shortName": "DIVIDEND RESTRICTIONS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfDividendPaymentRestrictionsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R45": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:StockholdersEquityNoteDisclosureTextBlock",
      "reportCount": 1,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211191018 - Disclosure - COMMON SHARES",
     "role": "http://www.eversource.com/role/COMMONSHARES",
     "shortName": "COMMON SHARES",
     "subGroupType": "",
     "uniqueAnchor": null
    },
    "R46": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PreferredStockTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211231019 - Disclosure - PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION",
     "role": "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTION",
     "shortName": "PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PreferredStockTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R47": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:StockholdersEquityNoteDisclosureTextBlock",
      "reportCount": 1,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211271020 - Disclosure - COMMON SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS",
     "role": "http://www.eversource.com/role/COMMONSHAREHOLDERSEQUITYANDNONCONTROLLINGINTERESTS",
     "shortName": "COMMON SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS",
     "subGroupType": "",
     "uniqueAnchor": null
    },
    "R48": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211291021 - Disclosure - EARNINGS PER SHARE",
     "role": "http://www.eversource.com/role/EARNINGSPERSHARE",
     "shortName": "EARNINGS PER SHARE",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R49": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RevenueFromContractWithCustomerTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211331022 - Disclosure - REVENUES",
     "role": "http://www.eversource.com/role/REVENUES",
     "shortName": "REVENUES",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RevenueFromContractWithCustomerTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R5": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Revenues",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100030005 - Statement - CONSOLIDATED STATEMENTS OF INCOME",
     "role": "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
     "shortName": "CONSOLIDATED STATEMENTS OF INCOME",
     "subGroupType": "",
     "uniqueAnchor": null
    },
    "R50": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SegmentReportingDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211371023 - Disclosure - SEGMENT INFORMATION",
     "role": "http://www.eversource.com/role/SEGMENTINFORMATION",
     "shortName": "SEGMENT INFORMATION",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SegmentReportingDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R51": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BusinessCombinationDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211411024 - Disclosure - ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS",
     "role": "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTS",
     "shortName": "ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BusinessCombinationDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R52": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:GoodwillDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211461025 - Disclosure - GOODWILL",
     "role": "http://www.eversource.com/role/GOODWILL",
     "shortName": "GOODWILL",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:GoodwillDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R53": {
     "firstAnchor": {
      "ancestors": [
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CondensedFinancialInformationOfParentCompanyOnlyDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211501026 - Disclosure - SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT",
     "role": "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANT",
     "shortName": "SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CondensedFinancialInformationOfParentCompanyOnlyDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R54": {
     "firstAnchor": {
      "ancestors": [
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "srt:ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "211551027 - Disclosure - SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES",
     "role": "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVES",
     "shortName": "SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "srt:ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R55": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfAccountingPolicyPolicyTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "220022001 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)",
     "role": "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies",
     "shortName": "SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)",
     "subGroupType": "policies",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfAccountingPolicyPolicyTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R56": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230033001 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)",
     "role": "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables",
     "shortName": "SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R57": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfRegulatoryAssetsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230153002 - Disclosure - REGULATORY ACCOUNTING (Tables)",
     "role": "http://www.eversource.com/role/REGULATORYACCOUNTINGTables",
     "shortName": "REGULATORY ACCOUNTING (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfRegulatoryAssetsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R58": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfPublicUtilityPropertyPlantAndEquipmentTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230203003 - Disclosure - PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION (Tables)",
     "role": "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONTables",
     "shortName": "PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfPublicUtilityPropertyPlantAndEquipmentTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R59": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230263004 - Disclosure - DERIVATIVE INSTRUMENTS (Tables)",
     "role": "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSTables",
     "shortName": "DERIVATIVE INSTRUMENTS (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R6": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100040006 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME",
     "role": "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
     "shortName": "CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R60": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230323005 - Disclosure - MARKETABLE SECURITIES (Tables)",
     "role": "http://www.eversource.com/role/MARKETABLESECURITIESTables",
     "shortName": "MARKETABLE SECURITIES (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R61": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EquityMethodInvestmentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230383006 - Disclosure - INVESTMENTS IN UNCONSOLIDATED AFFILIATES (Tables)",
     "role": "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESTables",
     "shortName": "INVESTMENTS IN UNCONSOLIDATED AFFILIATES (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EquityMethodInvestmentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R62": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfChangeInAssetRetirementObligationTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230423007 - Disclosure - ASSET RETIREMENT OBLIGATIONS (Tables)",
     "role": "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSTables",
     "shortName": "ASSET RETIREMENT OBLIGATIONS (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfChangeInAssetRetirementObligationTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R63": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfDebtTableTextBlock",
      "reportCount": 1,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230463008 - Disclosure - SHORT-TERM DEBT (Tables)",
     "role": "http://www.eversource.com/role/SHORTTERMDEBTTables",
     "shortName": "SHORT-TERM DEBT (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": null
    },
    "R64": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfDebtTableTextBlock",
      "reportCount": 1,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230503009 - Disclosure - LONG-TERM DEBT (Tables)",
     "role": "http://www.eversource.com/role/LONGTERMDEBTTables",
     "shortName": "LONG-TERM DEBT (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfDebtInstrumentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R65": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfVariableInterestEntitiesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230563010 - Disclosure - RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES (Tables)",
     "role": "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESTables",
     "shortName": "RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfVariableInterestEntitiesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R66": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230623011 - Disclosure - EMPLOYEE BENEFITS (Tables)",
     "role": "http://www.eversource.com/role/EMPLOYEEBENEFITSTables",
     "shortName": "EMPLOYEE BENEFITS (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R67": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230803012 - Disclosure - INCOME TAXES (Tables)",
     "role": "http://www.eversource.com/role/INCOMETAXESTables",
     "shortName": "INCOME TAXES (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R68": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfEnvironmentalLossContingenciesBySiteTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "230883013 - Disclosure - COMMITMENTS AND CONTINGENCIES (Tables)",
     "role": "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESTables",
     "shortName": "COMMITMENTS AND CONTINGENCIES (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfEnvironmentalLossContingenciesBySiteTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R69": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LeaseCostTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "231033014 - Disclosure - LEASES (Tables)",
     "role": "http://www.eversource.com/role/LEASESTables",
     "shortName": "LEASES (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LeaseCostTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R7": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i70af593ab79b4177a1b6e37163fae22c_I20181231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommonStockSharesOutstanding",
      "reportCount": 1,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100050007 - Statement - CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDERS' EQUITY",
     "role": "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
     "shortName": "CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDERS' EQUITY",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ie6858c6033ee408c8b3669acd3aa8ca3_I20181231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:StockholdersEquity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R70": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueByBalanceSheetGroupingTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "231103015 - Disclosure - FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)",
     "role": "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSTables",
     "shortName": "FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueByBalanceSheetGroupingTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R71": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "231133016 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) (Tables)",
     "role": "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSTables",
     "shortName": "ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R72": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfStockByClassTextBlock",
      "reportCount": 1,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "231203017 - Disclosure - COMMON SHARES (Tables)",
     "role": "http://www.eversource.com/role/COMMONSHARESTables",
     "shortName": "COMMON SHARES (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": null
    },
    "R73": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfStockByClassTextBlock",
      "reportCount": 1,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "231243018 - Disclosure - PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION (Tables)",
     "role": "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONTables",
     "shortName": "PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": null
    },
    "R74": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "231303019 - Disclosure - EARNINGS PER SHARE (Tables)",
     "role": "http://www.eversource.com/role/EARNINGSPERSHARETables",
     "shortName": "EARNINGS PER SHARE (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R75": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisaggregationOfRevenueTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "231343020 - Disclosure - REVENUES (Tables)",
     "role": "http://www.eversource.com/role/REVENUESTables",
     "shortName": "REVENUES (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisaggregationOfRevenueTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R76": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfSegmentReportingInformationBySegmentTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "231383021 - Disclosure - SEGMENT INFORMATION (Tables)",
     "role": "http://www.eversource.com/role/SEGMENTINFORMATIONTables",
     "shortName": "SEGMENT INFORMATION (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfSegmentReportingInformationBySegmentTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R77": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "231423022 - Disclosure - ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS (Tables)",
     "role": "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSTables",
     "shortName": "ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R78": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BusinessCombinationSegmentAllocationTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "231473023 - Disclosure - GOODWILL (Tables)",
     "role": "http://www.eversource.com/role/GOODWILLTables",
     "shortName": "GOODWILL (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BusinessCombinationSegmentAllocationTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R79": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "es:NumberofElectricNaturalGasAndWaterCustomers",
      "reportCount": 1,
      "unique": true,
      "unitRef": "customer",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240044001 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)",
     "role": "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
     "shortName": "SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "es:NumberofElectricNaturalGasAndWaterCustomers",
      "reportCount": 1,
      "unique": true,
      "unitRef": "customer",
      "xsiNil": "false"
     }
    },
    "R8": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommonStockDividendsPerShareCashPaid",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usdPerShare",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100060008 - Statement - CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDERS' EQUITY (Parenthetical)",
     "role": "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITYParenthetical",
     "shortName": "CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDERS' EQUITY (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommonStockDividendsPerShareCashPaid",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usdPerShare",
      "xsiNil": "false"
     }
    },
    "R80": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ifd35200350fd4700b14552ef695feeb3_I20201231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllowanceForDoubtfulAccountsReceivable",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240054002 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Allowance for Uncollectible Accounts (Details)",
     "role": "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
     "shortName": "SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Allowance for Uncollectible Accounts (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "es:AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R81": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "id3456111181f4211876889c4a264c60f_I20211231",
      "decimals": "-6",
      "first": true,
      "lang": "en-US",
      "name": "es:MaximumLoansReceivableOutstanding",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240064003 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES -Transfer of Energy Efficiency Loans (Details)",
     "role": "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTransferofEnergyEfficiencyLoansDetails",
     "shortName": "SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES -Transfer of Energy Efficiency Loans (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R82": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InventoryGross",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240074004 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Fuel, Materials, Supplies and Inventory (Details)",
     "role": "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails",
     "shortName": "SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Fuel, Materials, Supplies and Inventory (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InventoryGross",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R83": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "es:ScheduleOfFuelCostsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "es:FuelPowerCosts",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240084005 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Operating Expenses (Details)",
     "role": "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofOperatingExpensesDetails",
     "shortName": "SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Operating Expenses (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "es:ScheduleOfFuelCostsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "es:FuelPowerCosts",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R84": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "es:ScheduleOfAllowanceForFundsUsedDuringConstructionTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedInterest",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240094006 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of AFUDC and Weighted Average AFUDC (Details)",
     "role": "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAFUDCandWeightedAverageAFUDCDetails",
     "shortName": "SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of AFUDC and Weighted Average AFUDC (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "es:ScheduleOfAllowanceForFundsUsedDuringConstructionTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedInterest",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R85": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NonoperatingIncomeExpense",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240104007 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Other Income (Details)",
     "role": "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails",
     "shortName": "SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Other Income (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "es:OtherIncomeNetTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1c8add8d1da54a9eb07cefbbcc0654d0_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:NonoperatingIncomeExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R86": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ExciseAndSalesTaxes",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240114008 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Other Taxes (Details)",
     "role": "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofOtherTaxesDetails",
     "shortName": "SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Other Taxes (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ExciseAndSalesTaxes",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R87": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InterestPaidNet",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240124009 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Supplemental Cash Flow Information (Details)",
     "role": "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSupplementalCashFlowInformationDetails",
     "shortName": "SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Supplemental Cash Flow Information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:CapitalExpendituresIncurredButNotYetPaid",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R88": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Cash",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240134010 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Cash and Cash Equivalents (Details)",
     "role": "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails",
     "shortName": "SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Cash and Cash Equivalents (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfRestrictedCashAndCashEquivalentsTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ia1fd675cea0341638250bbffa790ba9b_I20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:RestrictedCashAndCashEquivalents",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R89": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RegulatoryAssets",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240164011 - Disclosure - REGULATORY ACCOUNTING - Components of Regulatory Assets (Details)",
     "role": "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
     "shortName": "REGULATORY ACCOUNTING - Components of Regulatory Assets (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i8af7d3a80f4b4c9eb83668f21eafed94_I20211231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:RegulatoryAssets",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R9": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "100070009 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS",
     "role": "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
     "shortName": "CONSOLIDATED STATEMENTS OF CASH FLOWS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:AmortizationOfDeferredCharges",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R90": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AmountOfRegulatoryCostsNotYetApproved",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240174012 - Disclosure - REGULATORY ACCOUNTING - Narrative (Details)",
     "role": "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
     "shortName": "REGULATORY ACCOUNTING - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AmountOfRegulatoryCostsNotYetApproved",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R91": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RegulatoryLiabilities",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240184013 - Disclosure - REGULATORY ACCOUNTING - Components of Regulatory Liabilities (Details)",
     "role": "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails",
     "shortName": "REGULATORY ACCOUNTING - Components of Regulatory Liabilities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RegulatoryLiabilities",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R92": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfPublicUtilityPropertyPlantAndEquipmentTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PublicUtilitiesPropertyPlantAndEquipmentDistribution",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240214014 - Disclosure - PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION - Investment in Utility Property, Plant and Equipment By Asset (Details)",
     "role": "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails",
     "shortName": "PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION - Investment in Utility Property, Plant and Equipment By Asset (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfPublicUtilityPropertyPlantAndEquipmentTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ibd2bf71e0052467db4f8a58f9268f323_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PublicUtilitiesPropertyPlantAndEquipmentDistribution",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R93": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ifd35200350fd4700b14552ef695feeb3_I20201231",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Assets",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240224015 - Disclosure - PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION -Narrative (Details)",
     "role": "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails",
     "shortName": "PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION -Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i441b73bbf28f4a76bb57053d5b1831fc_I20200731",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R94": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240234016 - Disclosure - PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION - Schedule of Aggregate Composite Depreciation Rates (Details)",
     "role": "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAggregateCompositeDepreciationRatesDetails",
     "shortName": "PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION - Schedule of Aggregate Composite Depreciation Rates (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R95": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "es:DistributionAssetsAverageUsefulLife",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240244017 - Disclosure - PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION - Schedule of Average Remaining Useful Lives of Depreciable Assets (Details)",
     "role": "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails",
     "shortName": "PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION - Schedule of Average Remaining Useful Lives of Depreciable Assets (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "es:DistributionAssetsAverageUsefulLife",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R96": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i76739cba95004a7eb6f725cc44e1662a_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DerivativeFairValueOfDerivativeLiability",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240274018 - Disclosure - DERIVATIVE INSTRUMENTS - Schedule of Gross Fair Value of Contracts (Details)",
     "role": "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
     "shortName": "DERIVATIVE INSTRUMENTS - Schedule of Gross Fair Value of Contracts (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i76739cba95004a7eb6f725cc44e1662a_I20211231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DerivativeFairValueOfDerivativeLiability",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R97": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "es:PercentageofCostsorBenefitsBorneUnderCapacityRelatedContractsbyUnitedIlluminatedCompany",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240284019 - Disclosure - DERIVATIVE INSTRUMENTS - Derivative Contracts at Fair Value (Details)",
     "role": "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
     "shortName": "DERIVATIVE INSTRUMENTS - Derivative Contracts at Fair Value (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1fea886b7bac478ca1b711d6a4864b63_D20210101-20211231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "es:PercentageofCostsorBenefitsBorneUnderCapacityRelatedContractsbyUnitedIlluminatedCompany",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R98": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ie3b3ae3eb8494682a301ab7d6ec20927_I20211231",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DerivativeAssetLiabilityNetMeasurementInput",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usdPerKWmo",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240294020 - Disclosure - DERIVATIVE INSTRUMENTS - Unobservable Inputs Utilized (Details)",
     "role": "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails",
     "shortName": "DERIVATIVE INSTRUMENTS - Unobservable Inputs Utilized (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ie3b3ae3eb8494682a301ab7d6ec20927_I20211231",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DerivativeAssetLiabilityNetMeasurementInput",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usdPerKWmo",
      "xsiNil": "false"
     }
    },
    "R99": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "ief09a3a4b99440a48a3a9397d8a687c8_I20201231",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "240304021 - Disclosure - DERIVATIVE INSTRUMENTS - Variations Using Significant unobservable Inputs (Details)",
     "role": "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSVariationsUsingSignificantunobservableInputsDetails",
     "shortName": "DERIVATIVE INSTRUMENTS - Variations Using Significant unobservable Inputs (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "es-20211231.htm",
      "contextRef": "i1710e9db9fa246b5a0cc8219a4d72e18_I20191231",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    }
   },
   "segmentCount": 291,
   "tag": {
    "dei_AmendmentFlag": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.",
        "label": "Amendment Flag",
        "terseLabel": "Amendment Flag"
       }
      }
     },
     "localname": "AmendmentFlag",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_AuditorFirmId": {
     "auth_ref": [
      "r967",
      "r968",
      "r969"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "PCAOB issued Audit Firm Identifier",
        "label": "Auditor Firm ID",
        "terseLabel": "Auditor Firm ID"
       }
      }
     },
     "localname": "AuditorFirmId",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/AuditInformation"
     ],
     "xbrltype": "nonemptySequenceNumberItemType"
    },
    "dei_AuditorLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Auditor [Line Items]",
        "terseLabel": "Auditor [Line Items]"
       }
      }
     },
     "localname": "AuditorLineItems",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/AuditInformation"
     ],
     "xbrltype": "stringItemType"
    },
    "dei_AuditorLocation": {
     "auth_ref": [
      "r967",
      "r968",
      "r969"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Auditor Location",
        "terseLabel": "Auditor Location"
       }
      }
     },
     "localname": "AuditorLocation",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/AuditInformation"
     ],
     "xbrltype": "internationalNameItemType"
    },
    "dei_AuditorName": {
     "auth_ref": [
      "r967",
      "r968",
      "r969"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Auditor Name",
        "terseLabel": "Auditor Name"
       }
      }
     },
     "localname": "AuditorName",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/AuditInformation"
     ],
     "xbrltype": "internationalNameItemType"
    },
    "dei_AuditorTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Auditor [Table]",
        "terseLabel": "Auditor [Table]"
       }
      }
     },
     "localname": "AuditorTable",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/AuditInformation"
     ],
     "xbrltype": "stringItemType"
    },
    "dei_CityAreaCode": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Area code of city",
        "label": "City Area Code",
        "terseLabel": "City Area Code"
       }
      }
     },
     "localname": "CityAreaCode",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_CoverAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cover page.",
        "label": "Cover [Abstract]",
        "terseLabel": "Cover [Abstract]"
       }
      }
     },
     "localname": "CoverAbstract",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "xbrltype": "stringItemType"
    },
    "dei_CurrentFiscalYearEndDate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "End date of current fiscal year in the format --MM-DD.",
        "label": "Current Fiscal Year End Date",
        "terseLabel": "Current Fiscal Year End Date"
       }
      }
     },
     "localname": "CurrentFiscalYearEndDate",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "gMonthDayItemType"
    },
    "dei_DocumentAnnualReport": {
     "auth_ref": [
      "r967",
      "r968",
      "r969"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true only for a form used as an annual report.",
        "label": "Document Annual Report",
        "terseLabel": "Document Annual Report"
       }
      }
     },
     "localname": "DocumentAnnualReport",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_DocumentFiscalPeriodFocus": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fiscal period values are FY, Q1, Q2, and Q3.  1st, 2nd and 3rd quarter 10-Q or 10-QT statements have value Q1, Q2, and Q3 respectively, with 10-K, 10-KT or other fiscal year statements having FY.",
        "label": "Document Fiscal Period Focus",
        "terseLabel": "Document Fiscal Period Focus"
       }
      }
     },
     "localname": "DocumentFiscalPeriodFocus",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "fiscalPeriodItemType"
    },
    "dei_DocumentFiscalYearFocus": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This is focus fiscal year of the document report in YYYY format. For a 2006 annual report, which may also provide financial information from prior periods, fiscal 2006 should be given as the fiscal year focus. Example: 2006.",
        "label": "Document Fiscal Year Focus",
        "terseLabel": "Document Fiscal Year Focus"
       }
      }
     },
     "localname": "DocumentFiscalYearFocus",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "gYearItemType"
    },
    "dei_DocumentPeriodEndDate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period.  The format of the date is YYYY-MM-DD.",
        "label": "Document Period End Date",
        "terseLabel": "Document Period End Date"
       }
      }
     },
     "localname": "DocumentPeriodEndDate",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "dateItemType"
    },
    "dei_DocumentTransitionReport": {
     "auth_ref": [
      "r970"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true only for a form used as a transition report.",
        "label": "Document Transition Report",
        "terseLabel": "Document Transition Report"
       }
      }
     },
     "localname": "DocumentTransitionReport",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_DocumentType": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.",
        "label": "Document Type",
        "terseLabel": "Document Type"
       }
      }
     },
     "localname": "DocumentType",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "submissionTypeItemType"
    },
    "dei_DocumentsIncorporatedByReferenceTextBlock": {
     "auth_ref": [
      "r965"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Documents incorporated by reference.",
        "label": "Documents Incorporated by Reference [Text Block]",
        "terseLabel": "Documents Incorporated by Reference"
       }
      }
     },
     "localname": "DocumentsIncorporatedByReferenceTextBlock",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "textBlockItemType"
    },
    "dei_EntitiesTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Container to assemble all relevant information about each entity associated with the document instance",
        "label": "Entities [Table]",
        "terseLabel": "Entities [Table]"
       }
      }
     },
     "localname": "EntitiesTable",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "stringItemType"
    },
    "dei_EntityAddressAddressLine1": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Address Line 1 such as Attn, Building Name, Street Name",
        "label": "Entity Address, Address Line One",
        "terseLabel": "Entity Address, Address Line One"
       }
      }
     },
     "localname": "EntityAddressAddressLine1",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressAddressLine2": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Address Line 2 such as Street or Suite number",
        "label": "Entity Address, Address Line Two",
        "terseLabel": "Entity Address, Address Line Two"
       }
      }
     },
     "localname": "EntityAddressAddressLine2",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressCityOrTown": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of the City or Town",
        "label": "Entity Address, City or Town",
        "terseLabel": "Entity Address, City or Town"
       }
      }
     },
     "localname": "EntityAddressCityOrTown",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressPostalZipCode": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Code for the postal or zip code",
        "label": "Entity Address, Postal Zip Code",
        "terseLabel": "Entity Address, Postal Zip Code"
       }
      }
     },
     "localname": "EntityAddressPostalZipCode",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressStateOrProvince": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of the state or province.",
        "label": "Entity Address, State or Province",
        "terseLabel": "Entity Address, State or Province"
       }
      }
     },
     "localname": "EntityAddressStateOrProvince",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "stateOrProvinceItemType"
    },
    "dei_EntityCentralIndexKey": {
     "auth_ref": [
      "r964"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.",
        "label": "Entity Central Index Key",
        "terseLabel": "Entity Central Index Key"
       }
      }
     },
     "localname": "EntityCentralIndexKey",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "centralIndexKeyItemType"
    },
    "dei_EntityCommonStockSharesOutstanding": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate number of shares or other units outstanding of each of registrant's classes of capital or common stock or other ownership interests, if and as stated on cover of related periodic report. Where multiple classes or units exist define each class/interest by adding class of stock items such as Common Class A [Member], Common Class B [Member] or Partnership Interest [Member] onto the Instrument [Domain] of the Entity Listings, Instrument.",
        "label": "Entity Common Stock, Shares Outstanding",
        "terseLabel": "Entity Common Stock, Shares Outstanding"
       }
      }
     },
     "localname": "EntityCommonStockSharesOutstanding",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "sharesItemType"
    },
    "dei_EntityCurrentReportingStatus": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate 'Yes' or 'No' whether registrants (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that registrants were required to file such reports), and (2) have been subject to such filing requirements for the past 90 days. This information should be based on the registrant's current or most recent filing containing the related disclosure.",
        "label": "Entity Current Reporting Status",
        "terseLabel": "Entity Current Reporting Status"
       }
      }
     },
     "localname": "EntityCurrentReportingStatus",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "All the names of the entities being reported upon in a document. Any legal structure used to conduct activities or to hold assets. Some examples of such structures are corporations, partnerships, limited liability companies, grantor trusts, and other trusts. This item does not include business and geographical segments which are included in the geographical or business segments domains.",
        "label": "Entity [Domain]",
        "terseLabel": "Entity [Domain]"
       }
      }
     },
     "localname": "EntityDomain",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSNarrativeDetails",
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSNarrativeDetails",
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails",
      "http://www.eversource.com/role/AuditInformation",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEversourceandNSTARElectricBostonHarborCivilActionDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESGuaranteesandObligationsNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofNumberofSitesandReservesDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofReconciliationofActivityinEnvironmentalReserveDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofTotalCostsIncurredDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails",
      "http://www.eversource.com/role/COMMONSHARESCommonSharesAuthorizedandIssuedDetails",
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETSParenthetical_1",
      "http://www.eversource.com/role/COVERPAGE",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSVariationsUsingSignificantunobservableInputsDetails",
      "http://www.eversource.com/role/DIVIDENDRESTRICTIONSDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofCompensationExpenseandIncomeTaxBenefitDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofDefinedContributionPlansDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofFundedStatusDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofOtherRetirementBenefitsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails",
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails",
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationofUnrecognizedTaxBenefitDetails",
      "http://www.eversource.com/role/INCOMETAXESTaxCreditsandLossCarryforwardsDetails",
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails",
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails",
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails",
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails",
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails",
      "http://www.eversource.com/role/LONGTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails",
      "http://www.eversource.com/role/MARKETABLESECURITIESEquitySecuritiesDetails",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETSParenthetical",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONNarrativeDetails",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAggregateCompositeDepreciationRatesDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETSParenthetical",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESIncomeStatementDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESNarrativeDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/REVENUESNarrativeDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONNarrativeDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAFUDCandWeightedAverageAFUDCDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofOperatingExpensesDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofOtherTaxesDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSupplementalCashFlowInformationDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTransferofEnergyEfficiencyLoansDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "domainItemType"
    },
    "dei_EntityEmergingGrowthCompany": {
     "auth_ref": [
      "r964"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate if registrant meets the emerging growth company criteria.",
        "label": "Entity Emerging Growth Company",
        "terseLabel": "Entity Emerging Growth Company"
       }
      }
     },
     "localname": "EntityEmergingGrowthCompany",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntityFileNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.",
        "label": "Entity File Number",
        "terseLabel": "Entity File Number"
       }
      }
     },
     "localname": "EntityFileNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "fileNumberItemType"
    },
    "dei_EntityFilerCategory": {
     "auth_ref": [
      "r964"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate whether the registrant is one of the following: Large Accelerated Filer, Accelerated Filer, Non-accelerated Filer. Definitions of these categories are stated in Rule 12b-2 of the Exchange Act. This information should be based on the registrant's current or most recent filing containing the related disclosure.",
        "label": "Entity Filer Category",
        "terseLabel": "Entity Filer Category"
       }
      }
     },
     "localname": "EntityFilerCategory",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "filerCategoryItemType"
    },
    "dei_EntityIncorporationStateCountryCode": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Two-character EDGAR code representing the state or country of incorporation.",
        "label": "Entity Incorporation, State or Country Code",
        "terseLabel": "Entity Incorporation, State or Country Code"
       }
      }
     },
     "localname": "EntityIncorporationStateCountryCode",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "edgarStateCountryItemType"
    },
    "dei_EntityInformationLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Entity Information [Line Items]",
        "terseLabel": "Entity Information [Line Items]"
       }
      }
     },
     "localname": "EntityInformationLineItems",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "stringItemType"
    },
    "dei_EntityInteractiveDataCurrent": {
     "auth_ref": [
      "r979"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true when the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).",
        "label": "Entity Interactive Data Current",
        "terseLabel": "Entity Interactive Data Current"
       }
      }
     },
     "localname": "EntityInteractiveDataCurrent",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityPublicFloat": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate market value of the voting and non-voting common equity held by non-affiliates computed by reference to the price at which the common equity was last sold, or the average bid and asked price of such common equity, as of the last business day of the registrant's most recently completed second fiscal quarter.",
        "label": "Entity Public Float",
        "terseLabel": "Entity Public Float"
       }
      }
     },
     "localname": "EntityPublicFloat",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "monetaryItemType"
    },
    "dei_EntityRegistrantName": {
     "auth_ref": [
      "r964"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.",
        "label": "Entity Registrant Name",
        "terseLabel": "Entity Registrant Name"
       }
      }
     },
     "localname": "EntityRegistrantName",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityShellCompany": {
     "auth_ref": [
      "r964"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true when the registrant is a shell company as defined in Rule 12b-2 of the Exchange Act.",
        "label": "Entity Shell Company",
        "terseLabel": "Entity Shell Company"
       }
      }
     },
     "localname": "EntityShellCompany",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntitySmallBusiness": {
     "auth_ref": [
      "r964"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates that the company is a Smaller Reporting Company (SRC).",
        "label": "Entity Small Business",
        "terseLabel": "Entity Small Business"
       }
      }
     },
     "localname": "EntitySmallBusiness",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntityTaxIdentificationNumber": {
     "auth_ref": [
      "r964"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.",
        "label": "Entity Tax Identification Number",
        "terseLabel": "Entity Tax Identification Number"
       }
      }
     },
     "localname": "EntityTaxIdentificationNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "employerIdItemType"
    },
    "dei_EntityVoluntaryFilers": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate 'Yes' or 'No' if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.",
        "label": "Entity Voluntary Filers",
        "terseLabel": "Entity Voluntary Filers"
       }
      }
     },
     "localname": "EntityVoluntaryFilers",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityWellKnownSeasonedIssuer": {
     "auth_ref": [
      "r1006"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate 'Yes' or 'No' if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Is used on Form Type: 10-K, 10-Q, 8-K, 20-F, 6-K, 10-K/A, 10-Q/A, 20-F/A, 6-K/A, N-CSR, N-Q, N-1A.",
        "label": "Entity Well-known Seasoned Issuer",
        "terseLabel": "Entity Well-known Seasoned Issuer"
       }
      }
     },
     "localname": "EntityWellKnownSeasonedIssuer",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_IcfrAuditorAttestationFlag": {
     "auth_ref": [
      "r967",
      "r968",
      "r969"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "ICFR Auditor Attestation Flag",
        "terseLabel": "ICFR Auditor Attestation Flag"
       }
      }
     },
     "localname": "IcfrAuditorAttestationFlag",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_LegalEntityAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The set of legal entities associated with a report.",
        "label": "Legal Entity [Axis]",
        "terseLabel": "Legal Entity [Axis]"
       }
      }
     },
     "localname": "LegalEntityAxis",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSNarrativeDetails",
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSNarrativeDetails",
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails",
      "http://www.eversource.com/role/AuditInformation",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEversourceandNSTARElectricBostonHarborCivilActionDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESGuaranteesandObligationsNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofNumberofSitesandReservesDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofReconciliationofActivityinEnvironmentalReserveDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofTotalCostsIncurredDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails",
      "http://www.eversource.com/role/COMMONSHARESCommonSharesAuthorizedandIssuedDetails",
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETSParenthetical_1",
      "http://www.eversource.com/role/COVERPAGE",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSVariationsUsingSignificantunobservableInputsDetails",
      "http://www.eversource.com/role/DIVIDENDRESTRICTIONSDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofCompensationExpenseandIncomeTaxBenefitDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofDefinedContributionPlansDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofFundedStatusDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofOtherRetirementBenefitsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails",
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails",
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationofUnrecognizedTaxBenefitDetails",
      "http://www.eversource.com/role/INCOMETAXESTaxCreditsandLossCarryforwardsDetails",
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails",
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails",
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails",
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails",
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails",
      "http://www.eversource.com/role/LONGTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails",
      "http://www.eversource.com/role/MARKETABLESECURITIESEquitySecuritiesDetails",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETSParenthetical",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONNarrativeDetails",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAggregateCompositeDepreciationRatesDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETSParenthetical",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESIncomeStatementDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESNarrativeDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/REVENUESNarrativeDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONNarrativeDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAFUDCandWeightedAverageAFUDCDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofOperatingExpensesDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofOtherTaxesDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSupplementalCashFlowInformationDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTransferofEnergyEfficiencyLoansDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "stringItemType"
    },
    "dei_LocalPhoneNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Local phone number for entity.",
        "label": "Local Phone Number",
        "terseLabel": "Local Phone Number"
       }
      }
     },
     "localname": "LocalPhoneNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_Security12bTitle": {
     "auth_ref": [
      "r963"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Title of a 12(b) registered security.",
        "label": "Title of 12(b) Security",
        "terseLabel": "Title of 12(b) Security"
       }
      }
     },
     "localname": "Security12bTitle",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "securityTitleItemType"
    },
    "dei_SecurityExchangeName": {
     "auth_ref": [
      "r966"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of the Exchange on which a security is registered.",
        "label": "Security Exchange Name",
        "terseLabel": "Security Exchange Name"
       }
      }
     },
     "localname": "SecurityExchangeName",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "edgarExchangeCodeItemType"
    },
    "dei_TradingSymbol": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Trading symbol of an instrument as listed on an exchange.",
        "label": "Trading Symbol",
        "terseLabel": "Trading Symbol"
       }
      }
     },
     "localname": "TradingSymbol",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.eversource.com/role/COVERPAGE"
     ],
     "xbrltype": "tradingSymbolItemType"
    },
    "es_A1950NotesDue2031Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "1.950% Notes Due 2031",
        "label": "1.950% Notes Due 2031 [Member]",
        "terseLabel": "1.950% due 2031"
       }
      }
     },
     "localname": "A1950NotesDue2031Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_A2200SeriesVDue2050Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "2.200% Series V Due 2050",
        "label": "2.200% Series V Due 2050 [Member]",
        "terseLabel": "2.200% Series V due 2031"
       }
      }
     },
     "localname": "A2200SeriesVDue2050Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_A2400SeriesUDue2050Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "2.400% Series U Due 2050",
        "label": "2.400% Series U Due 2050 [Member]",
        "terseLabel": "2.400% Series U due 2050"
       }
      }
     },
     "localname": "A2400SeriesUDue2050Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_A3100NotesDue2051Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "3.100% Notes Due 2051",
        "label": "3.100% Notes Due 2051 [Member]",
        "terseLabel": "3.100% due 2051"
       }
      }
     },
     "localname": "A3100NotesDue2051Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_A3950NotesDue2030Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "3.950% Notes Due 2030",
        "label": "3.950% Notes Due 2030 [Member]",
        "terseLabel": "3.950% due 2030"
       }
      }
     },
     "localname": "A3950NotesDue2030Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_AFUDCEquityMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "AFUDC Equity [Member]",
        "label": "AFUDC Equity [Member]",
        "terseLabel": "AFUDC Equity"
       }
      }
     },
     "localname": "AFUDCEquityMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accounts Receivable, Allowance For Credit Loss , Deferred Expense (Reversal)",
        "label": "Accounts Receivable, Allowance For Credit Loss , Deferred Expense (Reversal)",
        "terseLabel": "Uncollectible Costs Deferred"
       }
      }
     },
     "localname": "AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_AccountsReceivableAllowanceForCreditLossIncreaseFromBusinessCombination": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accounts Receivable, Allowance For Credit Loss, Increase From Business Combination",
        "label": "Accounts Receivable, Allowance For Credit Loss, Increase From Business Combination",
        "terseLabel": "Increase due to CMA acquisition"
       }
      }
     },
     "localname": "AccountsReceivableAllowanceForCreditLossIncreaseFromBusinessCombination",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_AccruedPensionSERPandPBOPMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accrued Pension, SERP and PBOP [Member]",
        "label": "Accrued Pension, SERP and PBOP [Member]",
        "terseLabel": "Accrued Pension, SERP and PBOP"
       }
      }
     },
     "localname": "AccruedPensionSERPandPBOPMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_AfudcTransmissionIncentiveMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "AFUDC is recorded on 100 percent of CL&amp;P's and WMECO's CWIP for their NEEWS projects, all of which is being reserved as a regulatory liability to reflect current rate base recovery for 100 percent of the CWIP as a result of FERC-approved transmission incentives.",
        "label": "AFUDC Transmission Incentive [Member]",
        "terseLabel": "AFUDC - Transmission"
       }
      }
     },
     "localname": "AfudcTransmissionIncentiveMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_AllowanceForFundsUsedDuringConstruction": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total value of the public utilities allowance for funds used during construction capitalized portions, including both the equity and debt portions",
        "label": "Allowance For Funds Used During Construction",
        "terseLabel": "Total AFUDC"
       }
      }
     },
     "localname": "AllowanceForFundsUsedDuringConstruction",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAFUDCandWeightedAverageAFUDCDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_AmortizationPriorServiceCostfromRegAsset": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The change in other regulatory asset due to the amortization of the net prior service costs (credit) into net periodic pension costs.",
        "label": "AmortizationPriorServiceCostfromRegAsset",
        "negatedTerseLabel": "Prior Service (Cost)/Credit Reclassified as Net Periodic Benefit (Expense)/Income"
       }
      }
     },
     "localname": "AmortizationPriorServiceCostfromRegAsset",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_AmortizationofRegulatoryAssetLiability": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 4.0,
       "parentTag": "us-gaap_OperatingExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortization of Regulatory Asset (Liability)",
        "label": "Amortization of Regulatory Asset (Liability)",
        "terseLabel": "Amortization of Regulatory Assets, Net"
       }
      }
     },
     "localname": "AmortizationofRegulatoryAssetLiability",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_AmountOfRegulatoryRecoveryNotYetApproved": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of Regulatory Recovery Not yet Approved",
        "label": "Amount of Regulatory Recovery Not yet Approved",
        "terseLabel": "Amount of regulatory recovery not yet approved"
       }
      }
     },
     "localname": "AmountOfRegulatoryRecoveryNotYetApproved",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_AmountofCapacityProvidedUnderCapacityContract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of Capacity Provided Under Capacity Contract",
        "label": "Amount of Capacity Provided Under Capacity Contract",
        "terseLabel": "Amount of power to be purchased under capacity-related contract (up to) (in MW)"
       }
      }
     },
     "localname": "AmountofCapacityProvidedUnderCapacityContract",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "powerItemType"
    },
    "es_AmountofNaturalGasToBePurchasedUnderFuturesContracts": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of Natural Gas To Be Purchased Under Futures Contracts",
        "label": "Amount of Natural Gas To Be Purchased Under Futures Contracts",
        "terseLabel": "Amount of natural gas to be purchased under futures contracts (in MMBtu)"
       }
      }
     },
     "localname": "AmountofNaturalGasToBePurchasedUnderFuturesContracts",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails"
     ],
     "xbrltype": "energyItemType"
    },
    "es_AquarionMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aquarion [Member]",
        "label": "Aquarion [Member]",
        "terseLabel": "Aquarion"
       }
      }
     },
     "localname": "AquarionMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_AquarionPlansMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aquarion Plans [Member]",
        "label": "Aquarion Plans [Member]",
        "terseLabel": "Aquarion Plans"
       }
      }
     },
     "localname": "AquarionPlansMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_AquarionWaterCompanyMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aquarion Water Company [Member]",
        "label": "Aquarion Water Company [Member]",
        "terseLabel": "Aquarion Water Company"
       }
      }
     },
     "localname": "AquarionWaterCompanyMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_AquarionWaterCompanyOfConnecticut331SeniorNotesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aquarion Water Company of Connecticut 3.31% Senior Notes",
        "label": "Aquarion Water Company of Connecticut 3.31% Senior Notes [Member]",
        "terseLabel": "Aquarion Water Company of Connecticut 3.31% Senior Notes"
       }
      }
     },
     "localname": "AquarionWaterCompanyOfConnecticut331SeniorNotesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_AquarionWaterCompanyOfConnecticut550NotesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aquarion Water Company of Connecticut 5.50% Notes",
        "label": "Aquarion Water Company of Connecticut 5.50% Notes [Member]",
        "terseLabel": "Aquarion Water Company of Connecticut 5.50% Notes"
       }
      }
     },
     "localname": "AquarionWaterCompanyOfConnecticut550NotesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_AssetRetirementObligationLiabilitiesAssumedInBusinessCombination": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Asset Retirement Obligation, Liabilities Assumed In Business Combination",
        "label": "Asset Retirement Obligation, Liabilities Assumed In Business Combination",
        "terseLabel": "Liability Assumed Upon CMA Asset Acquisition"
       }
      }
     },
     "localname": "AssetRetirementObligationLiabilitiesAssumedInBusinessCombination",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_AssetRetirementObligationsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Asset Retirement Obligations [Member]",
        "label": "Asset Retirement Obligations [Member]",
        "terseLabel": "Asset Retirement Obligations"
       }
      }
     },
     "localname": "AssetRetirementObligationsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Assetsrelatedto401hMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Assetsrelatedto401h [Member]",
        "terseLabel": "401 PBOP Assets"
       }
      }
     },
     "localname": "Assetsrelatedto401hMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_AssumedRateOfReturnOnDefinedBenefitPlanAssets": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the assumed rate of return for each class of pension and other post retirement benefit plan assets",
        "label": "Assumed Rate of Return on Defined Benefit Plan Assets",
        "verboseLabel": "Assumed rate of return"
       }
      }
     },
     "localname": "AssumedRateOfReturnOnDefinedBenefitPlanAssets",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_AuditInformationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Audit Information [Abstract]",
        "label": "Audit Information [Abstract]"
       }
      }
     },
     "localname": "AuditInformationAbstract",
     "nsuri": "http://www.eversource.com/20211231",
     "xbrltype": "stringItemType"
    },
    "es_BayStateWindLLCMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Bay State Wind LLC",
        "label": "Bay State Wind LLC [Member]",
        "terseLabel": "Bay State Wind LLC"
       }
      }
     },
     "localname": "BayStateWindLLCMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_BenefitCostsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Benefit Costs [Member]",
        "terseLabel": "Benefit Costs",
        "verboseLabel": "Benefit Costs"
       }
      }
     },
     "localname": "BenefitCostsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_BoardMembersMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Board Members [Member]",
        "label": "Board Members [Member]",
        "terseLabel": "Board Members"
       }
      }
     },
     "localname": "BoardMembersMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEnergyReliefFundLiability": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Energy Relief Fund Liability",
        "label": "Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Energy Relief Fund Liability",
        "terseLabel": "Energy relief fund liability"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEnergyReliefFundLiability",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesExcludingLongTermDebt": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities Excluding Long-Term Debt",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities Excluding Long-Term Debt",
        "negatedTerseLabel": "Other Noncurrent Liabilities"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesExcludingLongTermDebt",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedReserveForArrearageForgivenessCurrent": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Reserve For Arrearage Forgiveness, Current",
        "label": "Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Reserve For Arrearage Forgiveness, Current",
        "terseLabel": "Arrearage Forgiveness Fund"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedReserveForArrearageForgivenessCurrent",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRestrictedCashAndCashEquivalents": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Restricted Cash And Cash Equivalents",
        "label": "Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Restricted Cash And Cash Equivalents",
        "terseLabel": "Restricted Cash"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRestrictedCashAndCashEquivalents",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_BusinessCombinationTargetWorkingCapitalAmount": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Business Combination, Target Working Capital Amount",
        "label": "Business Combination, Target Working Capital Amount",
        "terseLabel": "Target working capital amount"
       }
      }
     },
     "localname": "BusinessCombinationTargetWorkingCapitalAmount",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_CLPNSTARElectricandPSNHMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "CL&amp;P, NSTAR Electric and PSNH [Member]",
        "label": "CL&amp;P, NSTAR Electric and PSNH [Member]",
        "terseLabel": "CL&amp;P, NSTAR Electric and PSNH"
       }
      }
     },
     "localname": "CLPNSTARElectricandPSNHMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_CLPRateAdjustmentMechanismsRAMMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "CL&amp;P Rate Adjustment Mechanisms (RAM)",
        "label": "CL&amp;P Rate Adjustment Mechanisms (RAM) [Member]",
        "terseLabel": "CL&amp;P Rate Adjustment Mechanisms (RAM)"
       }
      }
     },
     "localname": "CLPRateAdjustmentMechanismsRAMMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_CLPSettlementAgreementAndStormPerformancePenaltyMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "CL&amp;P Settlement Agreement and Storm Performance Penalty",
        "label": "CL&amp;P Settlement Agreement and Storm Performance Penalty [Member]",
        "terseLabel": "CL&amp;P Settlement Agreement and Storm Performance Penalty"
       }
      }
     },
     "localname": "CLPSettlementAgreementAndStormPerformancePenaltyMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_COVID19Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "COVID 19",
        "label": "COVID 19 [Member]",
        "terseLabel": "COVID 19"
       }
      }
     },
     "localname": "COVID19Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_CYAPCMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "CYAPC [Member]",
        "label": "CYAPC [Member]",
        "terseLabel": "CYAPC"
       }
      }
     },
     "localname": "CYAPCMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_CYAPCYAECAndMYAPCMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "CYAPC, YAEC, And MYAPC [Member]",
        "label": "CYAPC, YAEC, And MYAPC [Member]",
        "terseLabel": "CYAPC, YAEC, And MYAPC"
       }
      }
     },
     "localname": "CYAPCYAECAndMYAPCMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_CapacityProductionGuaranteeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Capacity Production Guarantee",
        "label": "Capacity Production Guarantee [Member]",
        "terseLabel": "OREC Capacity Production"
       }
      }
     },
     "localname": "CapacityProductionGuaranteeMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_CapacityRequiredForInstallationofDistributionCable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Capacity Required For Installation of Distribution Cable",
        "label": "Capacity Required For Installation of Distribution Cable",
        "terseLabel": "Amount of capacity required for installation of distribution cable (in kV)"
       }
      }
     },
     "localname": "CapacityRequiredForInstallationofDistributionCable",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEversourceandNSTARElectricBostonHarborCivilActionDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "es_Capacityavailableunderpreferredstockprovisions": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "capacity available under preferred stock provisions",
        "label": "capacity available under preferred stock provisions",
        "terseLabel": "Capacity available under preferred stock provisions"
       }
      }
     },
     "localname": "Capacityavailableunderpreferredstockprovisions",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_CapitalContributionsToSubsidiaries": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Capital Contributions To Subsidiaries",
        "negatedTerseLabel": "Capital Contributions to Subsidiaries"
       }
      }
     },
     "localname": "CapitalContributionsToSubsidiaries",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_CashFlowLesseeAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cash Flow, Lessee [Abstract]",
        "label": "Cash Flow, Lessee [Abstract]",
        "terseLabel": "Cash Paid for Amounts Included in the Measurement of Lease Liabilities:"
       }
      }
     },
     "localname": "CashFlowLesseeAbstract",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_Changeinassetsduetotransferofemployees": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Change in assets due to the merger of the service companies or transfer to employees amoung operating companies",
        "label": "ChangeInAssetsDueToTransferOfEmployees",
        "negatedTerseLabel": "Employee Transfers"
       }
      }
     },
     "localname": "Changeinassetsduetotransferofemployees",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_Changeinliabilityduetotransferofemployees": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Change in liability due to movement of emplyees due among operating companies or service companies",
        "label": "ChangeInLiabilityDueToTransferOfEmployees",
        "verboseLabel": "Employee Transfers"
       }
      }
     },
     "localname": "Changeinliabilityduetotransferofemployees",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_CharitableContribution": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of future tax deductions arising from contributions in excess of statutory limitations in historical filings, and which can only be realized if sufficient tax-basis income is generated in future periods to enable deductions to be taken and providing tax laws continue to allow such deductions.",
        "label": "Charitable Contribution",
        "terseLabel": "Federal and State Charitable Contribution"
       }
      }
     },
     "localname": "CharitableContribution",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTaxCreditsandLossCarryforwardsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_ColumbiaGasOfMassachusettsCMAMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Columbia Gas Of Massachusetts (CMA) [Member]",
        "label": "Columbia Gas Of Massachusetts (CMA) [Member]",
        "terseLabel": "CMA",
        "verboseLabel": "CMA"
       }
      }
     },
     "localname": "ColumbiaGasOfMassachusettsCMAMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails",
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails",
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSScheduleofProFormaInformationDetails",
      "http://www.eversource.com/role/GOODWILLNarrativeDetails",
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_CommercialMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Commercial [Member]",
        "label": "Commercial [Member]",
        "terseLabel": "Commercial"
       }
      }
     },
     "localname": "CommercialMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_ComponentsOfOtherOperatingCostsAndExpenseTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Components of Other Operating Costs and Expense [Table]",
        "label": "Components of Other Operating Costs and Expense [Table]",
        "terseLabel": "Components of Other Operating Costs and Expense [Table]"
       }
      }
     },
     "localname": "ComponentsOfOtherOperatingCostsAndExpenseTable",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAFUDCandWeightedAverageAFUDCDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_ComponentsofOtherOperatingCostsandExpenseLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Line Items] for Components of Other Operating Costs and Expense [Table]",
        "label": "Components of Other Operating Costs and Expense [Line Items]",
        "terseLabel": "Components of Other Operating Costs and Expense [Line Items]"
       }
      }
     },
     "localname": "ComponentsofOtherOperatingCostsandExpenseLineItems",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAFUDCandWeightedAverageAFUDCDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_ComputerSoftwareHardwareAndEquipmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Computer Software, Hardware And Equipment [Member]",
        "label": "Computer Software, Hardware And Equipment [Member]",
        "terseLabel": "Computer Software, Hardware and Equipment"
       }
      }
     },
     "localname": "ComputerSoftwareHardwareAndEquipmentMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_ConnecticutLightAndPowerCompany438SeriesAPCRBMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Connecticut Light And Power Company 4.38% Series A PCRB",
        "label": "Connecticut Light And Power Company 4.38% Series A PCRB [Member]",
        "terseLabel": "4.38% Series A PCRB"
       }
      }
     },
     "localname": "ConnecticutLightAndPowerCompany438SeriesAPCRBMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_ConnecticutMassachusettsandNewHampshireMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Connecticut, Massachusetts and New Hampshire [Member]",
        "label": "Connecticut, Massachusetts and New Hampshire [Member]",
        "terseLabel": "Connecticut, Massachusetts and New Hampshire"
       }
      }
     },
     "localname": "ConnecticutMassachusettsandNewHampshireMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_ContractualObligationEstimatedAnnualCost": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Contractual Obligation, Estimated Annual Cost",
        "label": "Contractual Obligation, Estimated Annual Cost",
        "terseLabel": "Estimated costs under construction contract"
       }
      }
     },
     "localname": "ContractualObligationEstimatedAnnualCost",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_ContractualObligationTermOfContract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Contractual Obligation, Term Of Contract",
        "label": "Contractual Obligation, Term Of Contract",
        "terseLabel": "Contract term"
       }
      }
     },
     "localname": "ContractualObligationTermOfContract",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_CostOfRemovalMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The regulated companies currently recover amounts in rates for future costs of removal of plant assets over the lives of the assets.",
        "label": "Cost Of Removal [Member]",
        "terseLabel": "Cost of Removal"
       }
      }
     },
     "localname": "CostOfRemovalMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_CyapcAndYaecMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "CYAPC and YAEC [Member]",
        "terseLabel": "CYAPC and YAEC",
        "verboseLabel": "CYAPC and YAEC"
       }
      }
     },
     "localname": "CyapcAndYaecMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSNarrativeDetails",
      "http://www.eversource.com/role/MARKETABLESECURITIESEquitySecuritiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_DebtInstrumentRefinancedAmount": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debt Instrument, Refinanced Amount",
        "label": "Debt Instrument, Refinanced Amount",
        "terseLabel": "Refinanced amount"
       }
      }
     },
     "localname": "DebtInstrumentRefinancedAmount",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DebtInstrumentRequestedForIssuanceFaceAmount": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debt Instrument, Requested For Issuance, Face Amount",
        "label": "Debt Instrument, Requested For Issuance, Face Amount",
        "terseLabel": "Amount of long-term debt requested for issuance"
       }
      }
     },
     "localname": "DebtInstrumentRequestedForIssuanceFaceAmount",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DeferredCompensationCashBasedArrangementsExpensePertainingToDeferredBenefits": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other retirement benefits are accounted for on an accrual basis and expensed over the service lives of the employees in accordance with accounting guidance for deferred compensation contracts.",
        "label": "Deferred Compensation Cash-based Arrangements, Expense Pertaining to Deferred Benefits",
        "terseLabel": "Other Retirement Benefits Expense"
       }
      }
     },
     "localname": "DeferredCompensationCashBasedArrangementsExpensePertainingToDeferredBenefits",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofOtherRetirementBenefitsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DeferredPreStagingAndStormRestorationCostsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Deferred Pre-Staging And Storm Restoration Costs",
        "label": "Deferred Pre-Staging And Storm Restoration Costs [Member]",
        "terseLabel": "Deferred Pre-Staging And Storm Restoration Costs"
       }
      }
     },
     "localname": "DeferredPreStagingAndStormRestorationCostsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_DeferredRegulatoryCosts": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Deferred Regulatory Costs",
        "label": "Deferred Regulatory Costs",
        "terseLabel": "Deferred costs"
       }
      }
     },
     "localname": "DeferredRegulatoryCosts",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DeferredRegulatoryCostsUncollectibleExpensesIncurred": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Deferred Regulatory Costs, Uncollectible Expenses Incurred",
        "label": "Deferred Regulatory Costs, Uncollectible Expenses Incurred",
        "terseLabel": "Deferred costs related to uncollectible expense"
       }
      }
     },
     "localname": "DeferredRegulatoryCostsUncollectibleExpensesIncurred",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DeferredStormRestorationCostsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Deferred Storm Restoration Costs [Member]",
        "label": "Deferred Storm Restoration Costs [Member]",
        "terseLabel": "Deferred Storm Restoration Costs"
       }
      }
     },
     "localname": "DeferredStormRestorationCostsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_DeferredTaxAssetPurchaseAccounting": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 7.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Deferred Tax Asset, Purchase Accounting",
        "terseLabel": "Purchase Accounting Adjustment"
       }
      }
     },
     "localname": "DeferredTaxAssetPurchaseAccounting",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DeferredTaxAssetsTaxEffectTaxRegulatoryLiabilities": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Deferred Tax Assets Tax Effect Tax Regulatory Liabilities",
        "terseLabel": "Tax Effect - Tax Regulatory Liabilities"
       }
      }
     },
     "localname": "DeferredTaxAssetsTaxEffectTaxRegulatoryLiabilities",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DeferredTaxLiabilitiesGoodwillRegulatoryAsset": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_DeferredTaxLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Deferred Tax Liabilities Goodwill Regulatory Asset",
        "terseLabel": "Goodwill Regulatory Asset - 1999 Merger"
       }
      }
     },
     "localname": "DeferredTaxLiabilitiesGoodwillRegulatoryAsset",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DeferredTaxLiabilitiesRegulatoryAssetsDerivativeAssets": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_DeferredTaxLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Deferred Tax Liabilities Regulatory Assets Derivative Assets",
        "terseLabel": "Derivative Assets"
       }
      }
     },
     "localname": "DeferredTaxLiabilitiesRegulatoryAssetsDerivativeAssets",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DeferredTaxLiabilitiesRegulatoryAssetsOtherRegulatoryDeferrals": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_DeferredTaxLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Deferred Tax Liabilities Regulatory Assets Other Regulatory Deferrals",
        "terseLabel": "Regulatory Deferrals - Assets"
       }
      }
     },
     "localname": "DeferredTaxLiabilitiesRegulatoryAssetsOtherRegulatoryDeferrals",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DeferredTaxLiabilitiesRegulatoryAssetsTaxEffectTaxRegulatoryAssets": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_DeferredTaxLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Deferred Tax Liabilities Regulatory Assets Tax Effect Tax Regulatory Assets",
        "terseLabel": "Tax Effect - Tax Regulatory Assets"
       }
      }
     },
     "localname": "DeferredTaxLiabilitiesRegulatoryAssetsTaxEffectTaxRegulatoryAssets",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DeferredTaxLiabilitiesResultingFromPropertyTaxAccrualsAndOther": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DeferredTaxLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Deferred Tax Liabilities Resulting From Property Tax Accruals And Other",
        "terseLabel": "Property Tax Accruals"
       }
      }
     },
     "localname": "DeferredTaxLiabilitiesResultingFromPropertyTaxAccrualsAndOther",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DefinedBenefitPlanBenefitsPaidLumpSum": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of benefit plan payments made in a lump sum to participants.",
        "label": "Defined Benefit Plan Benefits Paid Lump Sum",
        "negatedLabel": "Benefits Paid - Lump Sum",
        "terseLabel": "Benefits Paid - Lump Sum"
       }
      }
     },
     "localname": "DefinedBenefitPlanBenefitsPaidLumpSum",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DefinedBenefitPlanDebtSecurityPrivateDebtMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Defined Benefit Plan, Debt Security, Private Debt [Member]",
        "label": "Defined Benefit Plan, Debt Security, Private Debt [Member]",
        "terseLabel": "Private Debt"
       }
      }
     },
     "localname": "DefinedBenefitPlanDebtSecurityPrivateDebtMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_DefinedBenefitPlanDebtSecurityPublicHighYieldFixedIncomeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Defined Benefit Plan, Debt Security, Public High Yield Fixed Income [Member]",
        "label": "Defined Benefit Plan, Debt Security, Public High Yield Fixed Income [Member]",
        "terseLabel": "Public High Yield Fixed Income"
       }
      }
     },
     "localname": "DefinedBenefitPlanDebtSecurityPublicHighYieldFixedIncomeMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_DefinedBenefitPlanEquitySecuritiesEmergingMarketsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Defined Benefit Plan, Equity Securities, Emerging Markets [Member]",
        "label": "Defined Benefit Plan, Equity Securities, Emerging Markets [Member]",
        "terseLabel": "Emerging Markets"
       }
      }
     },
     "localname": "DefinedBenefitPlanEquitySecuritiesEmergingMarketsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_DefinedBenefitPlanEquitySecuritiesGlobalMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Defined Benefit Plan, Equity Securities, Global [Member]",
        "label": "Defined Benefit Plan, Equity Securities, Global [Member]",
        "terseLabel": "Global"
       }
      }
     },
     "localname": "DefinedBenefitPlanEquitySecuritiesGlobalMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_DefinedBenefitPlanFairValueofPlanAssetsUncategorized": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Defined Benefit Plan, Fair Value of Plan Assets, Uncategorized",
        "label": "Defined Benefit Plan, Fair Value of Plan Assets, Uncategorized",
        "terseLabel": "Uncategorized"
       }
      }
     },
     "localname": "DefinedBenefitPlanFairValueofPlanAssetsUncategorized",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DefinedBenefitPlanHealthCareTrendRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Defined Benefit Plan, Health Care Trend Rate",
        "label": "Defined Benefit Plan, Health Care Trend Rate",
        "terseLabel": "Health care trend rate"
       }
      }
     },
     "localname": "DefinedBenefitPlanHealthCareTrendRate",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_DefinedBenefitPlanImpactonLiabilityasaResultofChangeinDiscountRate": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Defined Benefit Plan, Impact on Liability as a Result of Change in Discount Rate",
        "label": "Defined Benefit Plan, Impact on Liability as a Result of Change in Discount Rate",
        "terseLabel": "Increase in liability due to amendment in pension plan"
       }
      }
     },
     "localname": "DefinedBenefitPlanImpactonLiabilityasaResultofChangeinDiscountRate",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DefinedBenefitPlanPaymentsSerp": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Defined Benefit Plan payments related to the NU SERP plan",
        "label": "Defined Benefit Plan, Payments SERP",
        "terseLabel": "Benefits Paid - SERP"
       }
      }
     },
     "localname": "DefinedBenefitPlanPaymentsSerp",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DefinedBenefitPlanPrepaidAssets": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Defined Benefit Plan, Prepaid Assets",
        "label": "Defined Benefit Plan, Prepaid Assets",
        "terseLabel": "Prepaid asset"
       }
      }
     },
     "localname": "DefinedBenefitPlanPrepaidAssets",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DefinedContributionPlan401KMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Defined Contribution Plan, 401K [Member]",
        "label": "Defined Contribution Plan, 401K [Member]",
        "terseLabel": "Defined Contribution Plan, 401K"
       }
      }
     },
     "localname": "DefinedContributionPlan401KMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSDefinedContributionPlanNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_DefinedContributionPlanAlternateContribution401KMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Defined Contribution Plan, Alternate Contribution 401K [Member]",
        "label": "Defined Contribution Plan, Alternate Contribution 401K [Member]",
        "terseLabel": "Defined Contribution Plan, Alternate Contribution 401K"
       }
      }
     },
     "localname": "DefinedContributionPlanAlternateContribution401KMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSDefinedContributionPlanNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_DerivativeInstrumentsGainLossRecognizedInRegulatoryAssetLiability": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Derivative Instruments Gain (Loss) Recognized In Regulatory Asset Liability",
        "label": "Derivative Instruments Gain (Loss) Recognized In Regulatory Asset Liability",
        "negatedLabel": "Loss deferred as regulatory costs"
       }
      }
     },
     "localname": "DerivativeInstrumentsGainLossRecognizedInRegulatoryAssetLiability",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_DistributionAssetsAverageUsefulLife": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Distribution Assets Average Useful Life",
        "label": "Distribution Assets Average Useful Life",
        "terseLabel": "Distribution - Electric"
       }
      }
     },
     "localname": "DistributionAssetsAverageUsefulLife",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_DistributionNaturalGasUsefulLife": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Distribution Natural Gas Useful Life",
        "label": "Distribution Natural Gas Useful Life",
        "terseLabel": "Distribution - Natural Gas"
       }
      }
     },
     "localname": "DistributionNaturalGasUsefulLife",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_EGMA211SeriesAFirstMortgageBondsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "EGMA 2.11% Series A First Mortgage Bonds",
        "label": "EGMA 2.11% Series A First Mortgage Bonds [Member]",
        "terseLabel": "EGMA 2.11% Series A First Mortgage Bonds"
       }
      }
     },
     "localname": "EGMA211SeriesAFirstMortgageBondsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EGMA292SeriesBFirstMortgageBondsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "EGMA 2.92% Series B First Mortgage Bonds",
        "label": "EGMA 2.92% Series B First Mortgage Bonds [Member]",
        "terseLabel": "EGMA 2.92% Series B First Mortgage Bonds"
       }
      }
     },
     "localname": "EGMA292SeriesBFirstMortgageBondsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EGMAMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "EGMA",
        "label": "EGMA [Member]",
        "terseLabel": "EGMA"
       }
      }
     },
     "localname": "EGMAMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EffectiveIncomeTaxRateReconciliationExcessStockBenefit": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails": {
       "order": 7.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Effective Income Tax Rate Reconciliation, Excess Stock Benefit",
        "label": "Effective Income Tax Rate Reconciliation, Excess Stock Benefit",
        "negatedTerseLabel": "Excess Stock Benefit",
        "terseLabel": "Excess stock benefit"
       }
      }
     },
     "localname": "EffectiveIncomeTaxRateReconciliationExcessStockBenefit",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_EffectiveTaxRateReconciliationPercentTaxEffectonShareBasedPayments": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Effective Tax Rate Reconciliation, Percent, Tax Effect on Share-Based Payments",
        "label": "Effective Tax Rate Reconciliation, Percent, Tax Effect on Share-Based Payments",
        "terseLabel": "Tax effect on total share-based payments (in percentage)"
       }
      }
     },
     "localname": "EffectiveTaxRateReconciliationPercentTaxEffectonShareBasedPayments",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_EmployeesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Employees [Member]",
        "label": "Employees [Member]",
        "terseLabel": "Employee"
       }
      }
     },
     "localname": "EmployeesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EnergyEfficiencyPrograms": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 5.0,
       "parentTag": "us-gaap_OperatingExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "These costs are in accordance with energy efficiency and conservation program guidelines established by regulators.",
        "label": "Energy Efficiency Programs",
        "terseLabel": "Energy Efficiency Programs"
       }
      }
     },
     "localname": "EnergyEfficiencyPrograms",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_EnergyReliefFundMerrimackValleyProgramsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Energy Relief Fund - Merrimack Valley Programs",
        "label": "Energy Relief Fund - Merrimack Valley Programs [Member]",
        "terseLabel": "Energy Relief Fund"
       }
      }
     },
     "localname": "EnergyReliefFundMerrimackValleyProgramsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EnvironmentalSiteQuantity": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of environmental sites by NU Entity in the remediation or long-term monitoring phase",
        "label": "Environmental Site Quantity",
        "terseLabel": "Number of sites",
        "verboseLabel": "Number of Sites"
       }
      }
     },
     "localname": "EnvironmentalSiteQuantity",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofNumberofSitesandReservesDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "es_EnvironmentalSiteQuantityRemaining": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Environmental Site Quantity Remaining",
        "label": "Environmental Site Quantity Remaining",
        "terseLabel": "Environmental site quantity remaining"
       }
      }
     },
     "localname": "EnvironmentalSiteQuantityRemaining",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "es_EnvironmentalSiteforWhichaRangeisTooEarlytoDetermineMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Environmental Site for Which a Range is Too Early to Determine [Member]",
        "label": "Environmental Site for Which a Range is Too Early to Determine [Member]",
        "terseLabel": "Environmental Site for Which a Range is Too Early to Determine"
       }
      }
     },
     "localname": "EnvironmentalSiteforWhichaRangeisTooEarlytoDetermineMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EnvironmentalSitesforWhichaRangeofLossExistsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Environmental Sites for Which a Range of Loss Exists [Member]",
        "label": "Environmental Sites for Which a Range of Loss Exists [Member]",
        "terseLabel": "Environmental Sites for Which a Range of Loss Exists"
       }
      }
     },
     "localname": "EnvironmentalSitesforWhichaRangeofLossExistsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquityGoodwill": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Equity Method Investment, Difference Between Carrying Amount And Underlying Equity, Goodwill",
        "label": "Equity Method Investment, Difference Between Carrying Amount And Underlying Equity, Goodwill",
        "terseLabel": "Goodwill"
       }
      }
     },
     "localname": "EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquityGoodwill",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_EquityinEarningsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Equity in Earnings [Member]",
        "label": "Equity in Earnings [Member]",
        "verboseLabel": "Equity in Earnings of Unconsolidated Affiliates"
       }
      }
     },
     "localname": "EquityinEarningsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Estimateofpossiblelossforeach10basispointchangetobaseROE": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Estimate of possible loss for each 10 basis point change to base ROE",
        "label": "Estimate of possible loss for each 10 basis point change to base ROE",
        "terseLabel": "Estimate of possible loss for each 10 basis point change to base ROE"
       }
      }
     },
     "localname": "Estimateofpossiblelossforeach10basispointchangetobaseROE",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_EversourceElectricDistributionMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Eversource Electric Distribution [Member]",
        "label": "Eversource Electric Distribution [Member]",
        "terseLabel": "Electric Distribution"
       }
      }
     },
     "localname": "EversourceElectricDistributionMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/GOODWILLSummaryofGoodwillbyReportableSegmentDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EversourceElectricTransmissionMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Eversource Electric Transmission [Member]",
        "label": "Eversource Electric Transmission [Member]",
        "terseLabel": "Electric Transmission"
       }
      }
     },
     "localname": "EversourceElectricTransmissionMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/GOODWILLSummaryofGoodwillbyReportableSegmentDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EversourceGasCompanyOfMassachusettsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Eversource Gas Company of Massachusetts",
        "label": "Eversource Gas Company of Massachusetts [Member]",
        "terseLabel": "Eversource Gas Company of Massachusetts"
       }
      }
     },
     "localname": "EversourceGasCompanyOfMassachusettsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EversourceInvestmentLLCMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Eversource Investment LLC",
        "label": "Eversource Investment LLC [Member]",
        "terseLabel": "Eversource Investment LLC"
       }
      }
     },
     "localname": "EversourceInvestmentLLCMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESGuaranteesandObligationsNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EversourceParent140SeriesUSeniorNotesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Eversource Parent 1.40% Series U Senior Notes",
        "label": "Eversource Parent 1.40% Series U Senior Notes [Member]",
        "terseLabel": "Eversource Parent 1.40% Series U Senior Notes"
       }
      }
     },
     "localname": "EversourceParent140SeriesUSeniorNotesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EversourceParent250SeriesISeniorNotesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Eversource Parent 2.50% Series I Senior Notes",
        "label": "Eversource Parent 2.50% Series I Senior Notes [Member]",
        "terseLabel": "Eversource Parent 2.50% Series I Senior Notes"
       }
      }
     },
     "localname": "EversourceParent250SeriesISeniorNotesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EversourceParent255SeriesSSeniorNotesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Eversource Parent 2.55% Series S Senior Notes",
        "label": "Eversource Parent 2.55% Series S Senior Notes [Member]",
        "terseLabel": "Eversource Parent 2.55% Series S Senior Notes"
       }
      }
     },
     "localname": "EversourceParent255SeriesSSeniorNotesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EversourceParentSeniorNotesDue20222050Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Eversource Parent - Senior Notes Due 2022-2050",
        "label": "Eversource Parent - Senior Notes Due 2022-2050 [Member]",
        "terseLabel": "Eversource Parent - Senior Notes 0.300% - 4.250% due 2022 - 2050"
       }
      }
     },
     "localname": "EversourceParentSeniorNotesDue20222050Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EversourceParentVariableRateSeriesTSeniorNotesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Eversource Parent Variable Rate Series T Senior Notes",
        "label": "Eversource Parent Variable Rate Series T Senior Notes [Member]",
        "terseLabel": "Eversource Parent Variable Rate Series T Senior Notes"
       }
      }
     },
     "localname": "EversourceParentVariableRateSeriesTSeniorNotesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EversourceServicePensionAndPBOPPlansMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Eversource Service Pension And PBOP Plans [Member]",
        "label": "Eversource Service Pension And PBOP Plans [Member]",
        "terseLabel": "Eversource Service Pension and PBOP Plans"
       }
      }
     },
     "localname": "EversourceServicePensionAndPBOPPlansMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EversourceWaterMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Eversource Water [Member]",
        "label": "Eversource Water [Member]",
        "terseLabel": "Water Distribution"
       }
      }
     },
     "localname": "EversourceWaterMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_EvironmentalSiteswithBestEstimateMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Evironmental Sites with Best Estimate [Member]",
        "label": "Evironmental Sites with Best Estimate [Member]",
        "terseLabel": "Evironmental Sites with Best Estimate"
       }
      }
     },
     "localname": "EvironmentalSiteswithBestEstimateMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_ExcessADITduetotaxCutsandJobsActMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Excess ADIT due to tax Cuts and Jobs Act [Member]",
        "label": "Excess ADIT due to tax Cuts and Jobs Act [Member]",
        "terseLabel": "EDIT due to Tax Cuts and Jobs Act of 2017"
       }
      }
     },
     "localname": "ExcessADITduetotaxCutsandJobsActMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_FERCROEComplaintsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "FERC ROE Complaints [Member]",
        "label": "FERC ROE Complaints [Member]",
        "terseLabel": "FERC ROE Complaints"
       }
      }
     },
     "localname": "FERCROEComplaintsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_FERCROEFirstComplaintMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "FERC ROE First Complaint [Member]",
        "label": "FERC ROE First Complaint [Member]",
        "terseLabel": "FERC ROE First Complaint"
       }
      }
     },
     "localname": "FERCROEFirstComplaintMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_FERCROEFirstSecondandThirdComplaintsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "FERC ROE First, Second and Third Complaints [Member]",
        "label": "FERC ROE First, Second and Third Complaints [Member]",
        "terseLabel": "FERC ROE First, Second and Third Complaints"
       }
      }
     },
     "localname": "FERCROEFirstSecondandThirdComplaintsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_FERCROEFirstandSecondComplaintsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "FERC ROE First and Second Complaints [Member]",
        "label": "FERC ROE First and Second Complaints [Member]",
        "terseLabel": "FERC ROE Complaints"
       }
      }
     },
     "localname": "FERCROEFirstandSecondComplaintsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_FERCROEFourthComplaintMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "FERC ROE Fourth Complaint [Member]",
        "label": "FERC ROE Fourth Complaint [Member]",
        "terseLabel": "FERC ROE Fourth Complaint"
       }
      }
     },
     "localname": "FERCROEFourthComplaintMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_FERCROESecondComplaintMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "FERC ROE Second Complaint [Member]",
        "label": "FERC ROE Second Complaint [Member]",
        "terseLabel": "FERC ROE Second Complaint"
       }
      }
     },
     "localname": "FERCROESecondComplaintMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_FairValueAdjustmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Fair Value Adjustment [Member]",
        "terseLabel": "Fair Value Adjustment"
       }
      }
     },
     "localname": "FairValueAdjustmentMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_FairValueHeirarchyTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Fair Value Heirarchy [Table Text Block]",
        "terseLabel": "Marketable Securities Recorded at Fair Value"
       }
      }
     },
     "localname": "FairValueHeirarchyTableTextBlock",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "es_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetLiabilityGainLossIncludedInRegulatoryAssetLiability": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Liability Gain (Loss) Included In Regulatory Asset Liability",
        "label": "Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Liability Gain (Loss) Included In Regulatory Asset Liability",
        "negatedTerseLabel": "Net Realized/Unrealized Losses Included in Regulatory Assets"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetLiabilityGainLossIncludedInRegulatoryAssetLiability",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSVariationsUsingSignificantunobservableInputsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_FairvalueadjustmentmembercurrentportionMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "FairValueAdjustmentMemberCurrentPortion [Member]",
        "terseLabel": "Fair Value Adjustment - Current Portion"
       }
      }
     },
     "localname": "FairvalueadjustmentmembercurrentportionMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_FinanceLeaseCost": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_LeaseCost",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Finance Lease, Cost",
        "label": "Finance Lease, Cost",
        "totalLabel": "Total Finance Lease Cost"
       }
      }
     },
     "localname": "FinanceLeaseCost",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_FixedrateTaxExemptDue2028Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fixed rate Tax Exempt Due 2028 [Member]",
        "label": "Fixed rate Tax Exempt Due 2028 [Member]",
        "terseLabel": "4.375% Fixed Rate Tax Exempt due 2028"
       }
      }
     },
     "localname": "FixedrateTaxExemptDue2028Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_FuelPowerCosts": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fuel power costs included in Fuel, Purchased and Net Interchange line item on the income statement",
        "label": "Fuel Power Costs",
        "terseLabel": "Natural gas and fuel costs"
       }
      }
     },
     "localname": "FuelPowerCosts",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofOperatingExpensesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_GainLossArisingDuringYearRegulatoryAsset": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Pretax change in the value of either the benefit obligation or the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption, or the consequence of a decision to temporarily deviate from the substantive plan, that has not been recognized in net periodic benefit cost.",
        "label": "Gain Loss Arising During Year Regulatory",
        "terseLabel": "Actuarial (Gains)/Losses Arising During the Year"
       }
      }
     },
     "localname": "GainLossArisingDuringYearRegulatoryAsset",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_GainLossOnDispositionOfPropertyPlantAndEquipmentNetOfTax": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Gain Loss on Disposition of Property Plant and Equipment Net of Tax",
        "label": "Gain Loss on Disposition of Property Plant and Equipment Net of Tax",
        "terseLabel": "After-tax gain (loss) on the sale of property, plant and equipment"
       }
      }
     },
     "localname": "GainLossOnDispositionOfPropertyPlantAndEquipmentNetOfTax",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_GainLossRelatedToLitigationSettlementNetOfTax": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Gain \u200b(Loss) Related To Litigation Settlement, Net Of Tax",
        "label": "Gain \u200b(Loss) Related To Litigation Settlement, Net Of Tax",
        "negatedTerseLabel": "Loss related to litigation settlement, net of tax"
       }
      }
     },
     "localname": "GainLossRelatedToLitigationSettlementNetOfTax",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_GainLossRelatedToLitigationSettlementNetOfTaxPerShare": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Gain \u200b(Loss) Related to Litigation Settlement, Net Of Tax, Per Share",
        "label": "Gain \u200b(Loss) Related to Litigation Settlement, Net Of Tax, Per Share",
        "negatedLabel": "Loss contingency, after-tax earnings impact per share (in dollars per share)",
        "terseLabel": "Loss contingency, after-tax earnings impact per share (in dollars per share)"
       }
      }
     },
     "localname": "GainLossRelatedToLitigationSettlementNetOfTaxPerShare",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPTropicalStormIsaiasResponseInvestigationDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "es_GenerationAssetsAverageUsefulLife": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Generation Assets Average Useful Life",
        "label": "Generation Assets Average Useful Life",
        "terseLabel": "Solar"
       }
      }
     },
     "localname": "GenerationAssetsAverageUsefulLife",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_GoodwillRegulatoryAssetMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Goodwill that originated from the merger that created NSTAR in 1999.",
        "label": "Goodwill Regulatory Asset [Member]",
        "terseLabel": "Goodwill-related"
       }
      }
     },
     "localname": "GoodwillRegulatoryAssetMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_GuarantorObligationsMaximumExposurePercentOfObligation": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Guarantor Obligations, Maximum Exposure, Percent Of Obligation",
        "label": "Guarantor Obligations, Maximum Exposure, Percent Of Obligation",
        "terseLabel": "Percent of obligations guaranteed"
       }
      }
     },
     "localname": "GuarantorObligationsMaximumExposurePercentOfObligation",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_HardshipAccountsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Hardship Accounts",
        "label": "Hardship Accounts [Member]",
        "terseLabel": "Hardship Accounts"
       }
      }
     },
     "localname": "HardshipAccountsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_HinghamWaterSystemMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Hingham Water System",
        "label": "Hingham Water System [Member]",
        "terseLabel": "Hingham Water System"
       }
      }
     },
     "localname": "HinghamWaterSystemMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/GOODWILLNarrativeDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_HydroQuebecSystemMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Hydro-Quebec System [Member]",
        "label": "Hydro-Quebec System [Member]",
        "terseLabel": "Hydro-Quebec System"
       }
      }
     },
     "localname": "HydroQuebecSystemMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_IncreaseDecreaseInDeferralCost": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Increase (Decrease) in Deferral Cost",
        "label": "Increase (Decrease) in Deferral Cost",
        "negatedTerseLabel": "Decrease in deferral cost"
       }
      }
     },
     "localname": "IncreaseDecreaseInDeferralCost",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_IncrementalCommonSharesAttributableToDilutiveEffectOfShareBasedPaymentArrangementsAndOther": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment",
       "weight": 1.0
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Incremental Common Shares Attributable To Dilutive Effect Of Share-Based Payment Arrangements And Other",
        "label": "Incremental Common Shares Attributable To Dilutive Effect Of Share-Based Payment Arrangements And Other",
        "terseLabel": "Share-Based Compensation Awards and Other (in shares)"
       }
      }
     },
     "localname": "IncrementalCommonSharesAttributableToDilutiveEffectOfShareBasedPaymentArrangementsAndOther",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "es_IndustrialMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Industrial [Member]",
        "label": "Industrial [Member]",
        "terseLabel": "Industrial"
       }
      }
     },
     "localname": "IndustrialMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_InterestIncludedInPaymentToSettleSpentNuclearFuelObligation": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount represents the interest included in the payment to settle the spent nuclear fuel obligation",
        "label": "Interest included in payment to settle spent nuclear fuel obligation",
        "terseLabel": "Interest included in payment to settle spent nuclear fuel obligation"
       }
      }
     },
     "localname": "InterestIncludedInPaymentToSettleSpentNuclearFuelObligation",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_InterestPaidExcludingCapitalizedInterestOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Interest Paid, Excluding Capitalized Interest, Operating Activities [Abstract]",
        "label": "Interest Paid, Excluding Capitalized Interest, Operating Activities [Abstract]",
        "terseLabel": "Cash Paid/(Received) During the Year for:"
       }
      }
     },
     "localname": "InterestPaidExcludingCapitalizedInterestOperatingActivitiesAbstract",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_InvestmentIncomeLossMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Investment Income (Loss) [Member]",
        "label": "Investment Income (Loss) [Member]",
        "terseLabel": "Investment Income/(Loss)"
       }
      }
     },
     "localname": "InvestmentIncomeLossMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_LesseeLeaseFinanceLeaseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Lessee, Lease, Finance Lease [Abstract]",
        "label": "Lessee, Lease, Finance Lease [Abstract]",
        "terseLabel": "Finance Leases:"
       }
      }
     },
     "localname": "LesseeLeaseFinanceLeaseAbstract",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_LesseeLeaseOperatingLeaseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Lessee, Lease, Operating Lease [Abstract]",
        "label": "Lessee, Lease, Operating Lease [Abstract]",
        "terseLabel": "Operating Leases:"
       }
      }
     },
     "localname": "LesseeLeaseOperatingLeaseAbstract",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_LesseeLeaseSupplementalNonCashInformationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Lessee, Lease, Supplemental Non-Cash Information [Abstract]",
        "label": "Lessee, Lease, Supplemental Non-Cash Information [Abstract]",
        "terseLabel": "Supplemental Non-Cash Information on Lease Liabilities:"
       }
      }
     },
     "localname": "LesseeLeaseSupplementalNonCashInformationAbstract",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_LesseeLeaseWeightedAverageDiscountRateAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Lessee, Lease, Weighted Average Discount Rate [Abstract]",
        "label": "Lessee, Lease, Weighted Average Discount Rate [Abstract]",
        "terseLabel": "Weighted-Average Discount Rate (Percentage):"
       }
      }
     },
     "localname": "LesseeLeaseWeightedAverageDiscountRateAbstract",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_LesseeLeaseWeightedAverageRemainingLeaseTermAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Lessee, Lease, Weighted Average Remaining Lease Term [Abstract]",
        "label": "Lessee, Lease, Weighted Average Remaining Lease Term [Abstract]",
        "terseLabel": "Weighted-Average Remaining Lease Term (Years):"
       }
      }
     },
     "localname": "LesseeLeaseWeightedAverageRemainingLeaseTermAbstract",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_LesseeLeasesOtherInformationTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Lessee, Leases, Other Information [Table Text Block]",
        "label": "Lessee, Leases, Other Information [Table Text Block]",
        "terseLabel": "Other Information Related to Leases"
       }
      }
     },
     "localname": "LesseeLeasesOtherInformationTableTextBlock",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LEASESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "es_LesseeLeasesSupplementalBalanceSheetInformationTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Lessee, Leases, Supplemental Balance Sheet Information [Table Text Block]",
        "label": "Lessee, Leases, Supplemental Balance Sheet Information [Table Text Block]",
        "terseLabel": "Supplemental Balance Sheet Information Related to Leases"
       }
      }
     },
     "localname": "LesseeLeasesSupplementalBalanceSheetInformationTableTextBlock",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LEASESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "es_LesseeOperatingAndFinanceLeaseRenewalTerm": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Lessee, Operating And Finance Lease, Renewal Term",
        "label": "Lessee, Operating And Finance Lease, Renewal Term",
        "terseLabel": "Renewal period"
       }
      }
     },
     "localname": "LesseeOperatingAndFinanceLeaseRenewalTerm",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LEASESNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_LineofCreditFacilityAmountOutstandingDuringPeriod": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line of Credit Facility, Amount Outstanding During Period",
        "label": "Line of Credit Facility, Amount Outstanding During Period",
        "terseLabel": "Amount outstanding during period"
       }
      }
     },
     "localname": "LineofCreditFacilityAmountOutstandingDuringPeriod",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_LongTermPurchaseCommitmentEnergyProductionCapacity": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-Term Purchase Commitment, Energy Production Capacity",
        "label": "Long-Term Purchase Commitment, Energy Production Capacity",
        "terseLabel": "Nameplate capacity (in MW)"
       }
      }
     },
     "localname": "LongTermPurchaseCommitmentEnergyProductionCapacity",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "es_LongTermReceivableFromNusco": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Long Term Receivable From Nusco",
        "terseLabel": "Long term receivable"
       }
      }
     },
     "localname": "LongTermReceivableFromNusco",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_Longtermdebtmaturitiesrepaymentsofprincipaltotal": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of long-term debt maturities at the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed of determinable prices and dates.",
        "label": "LongTermDebtMaturitiesRepaymentsOfPrincipalTotal",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "Longtermdebtmaturitiesrepaymentsofprincipaltotal",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_LossContingencyAccidentReportingViolationFines": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Accident Reporting Violation Fines",
        "label": "Loss Contingency, Accident Reporting Violation Fines",
        "terseLabel": "Loss contingency, accident reporting violation fines"
       }
      }
     },
     "localname": "LossContingencyAccidentReportingViolationFines",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPTropicalStormIsaiasResponseInvestigationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_LossContingencyAllowedRateOfROE": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Allowed Rate Of ROE",
        "label": "Loss Contingency, Allowed Rate Of ROE",
        "terseLabel": "Loss contingency, allowed rate of ROE"
       }
      }
     },
     "localname": "LossContingencyAllowedRateOfROE",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPTropicalStormIsaiasResponseInvestigationDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_LossContingencyBaseROEPercentageChallengedbyComplainants": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Percentage of Base ROE Challenged by Complainants",
        "label": "Loss Contingency, Base ROE Percentage Challenged by Complainants",
        "terseLabel": "Base ROE percentage challenged by complainants"
       }
      }
     },
     "localname": "LossContingencyBaseROEPercentageChallengedbyComplainants",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_LossContingencyBasisPointsReductionToReturnOnEquityScenarioOne": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Basis Points Reduction To Return On Equity, Scenario One",
        "label": "Loss Contingency, Basis Points Reduction To Return On Equity, Scenario One",
        "terseLabel": "Basis points reduction to return on equity, scenario one"
       }
      }
     },
     "localname": "LossContingencyBasisPointsReductionToReturnOnEquityScenarioOne",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_LossContingencyBasisPointsReductionToReturnOnEquityScenarioTwo": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Basis Points Reduction To Return On Equity, Scenario Two",
        "label": "Loss Contingency, Basis Points Reduction To Return On Equity, Scenario Two",
        "terseLabel": "Basis points reduction to return on equity, scenario two"
       }
      }
     },
     "localname": "LossContingencyBasisPointsReductionToReturnOnEquityScenarioTwo",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_LossContingencyBasisSpread": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Basis Spread",
        "label": "Loss Contingency, Basis Spread",
        "terseLabel": "Basis point change"
       }
      }
     },
     "localname": "LossContingencyBasisSpread",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_LossContingencyCumulativePreTaxReservesWhichIncludeImpactofRefundsGiventoCustomers": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Cumulative Pre-Tax Reserves Which Include Impact of Refunds Given to Customers",
        "label": "Loss Contingency, Cumulative Pre-Tax Reserves Which Include Impact of Refunds Given to Customers",
        "terseLabel": "Cumulative pre-tax reserves which include impact of refunds given to customers"
       }
      }
     },
     "localname": "LossContingencyCumulativePreTaxReservesWhichIncludeImpactofRefundsGiventoCustomers",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_LossContingencyDamagesSoughtRemainingAmount": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Damages Sought, Remaining Amount",
        "label": "Loss Contingency, Damages Sought, Remaining Amount",
        "terseLabel": "Remaining damages sought"
       }
      }
     },
     "localname": "LossContingencyDamagesSoughtRemainingAmount",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_LossContingencyEstimateOfPossibleLossAccidentReportingViolationFines": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Estimate of Possible Loss, Accident Reporting Violation Fines",
        "label": "Loss Contingency, Estimate of Possible Loss, Accident Reporting Violation Fines",
        "terseLabel": "Loss contingency, estimate of possible earnings impact, accident reporting violation fines"
       }
      }
     },
     "localname": "LossContingencyEstimateOfPossibleLossAccidentReportingViolationFines",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPTropicalStormIsaiasResponseInvestigationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_LossContingencyEstimateOfPossibleLossNonComplianceFine": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Estimate of Possible Loss, Non-Compliance Fine",
        "label": "Loss Contingency, Estimate of Possible Loss, Non-Compliance Fine",
        "terseLabel": "Loss contingency, estimate of possible earnings impact, non-compliance with performance standards"
       }
      }
     },
     "localname": "LossContingencyEstimateOfPossibleLossNonComplianceFine",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPTropicalStormIsaiasResponseInvestigationDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/REVENUESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_LossContingencyMaximumpercentageofROEforincentiveprojects": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Maximum percentage of ROE for incentive projects",
        "label": "Loss Contingency, Maximum percentage of ROE for incentive projects",
        "terseLabel": "Maximum percentage cap of ROE for incentive projects"
       }
      }
     },
     "localname": "LossContingencyMaximumpercentageofROEforincentiveprojects",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_LossContingencyNonComplianceFine": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Non-Compliance Fine",
        "label": "Loss Contingency, Non-Compliance Fine",
        "terseLabel": "Non-compliance fine"
       }
      }
     },
     "localname": "LossContingencyNonComplianceFine",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPTropicalStormIsaiasResponseInvestigationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_LossContingencyOriginalBaseROEAuthorizedbyFERCatTimeofComplaint": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Original Base ROE Authorized by FERC at Time of Complaint",
        "label": "Loss Contingency, Original Base ROE Authorized by FERC at Time of Complaint",
        "terseLabel": "Original base ROE authorized by FERC at time of complaint"
       }
      }
     },
     "localname": "LossContingencyOriginalBaseROEAuthorizedbyFERCatTimeofComplaint",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_LossContingencyPenaltyAsAPercentOfDistributionRevenues": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Penalty As a Percent Of Distribution Revenues",
        "label": "Loss Contingency, Penalty As a Percent Of Distribution Revenues",
        "terseLabel": "Loss contingency, penalty rate as a percent of distribution revenues"
       }
      }
     },
     "localname": "LossContingencyPenaltyAsAPercentOfDistributionRevenues",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPTropicalStormIsaiasResponseInvestigationDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_LossContingencyPercentageOfBaseROEReasonablyJustified": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Percentage Of Base ROE Reasonably Justified",
        "label": "Loss Contingency, Percentage Of Base ROE Reasonably Justified",
        "terseLabel": "Percentage of base ROE reasonably justified"
       }
      }
     },
     "localname": "LossContingencyPercentageOfBaseROEReasonablyJustified",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_LossContingencyPercentageOfIncentiveCapOnTotalROE": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Percentage Of Incentive Cap On Total ROE",
        "label": "Loss Contingency, Percentage Of Incentive Cap On Total ROE",
        "terseLabel": "Percentage of incentive cap on total ROE"
       }
      }
     },
     "localname": "LossContingencyPercentageOfIncentiveCapOnTotalROE",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_LossContingencyPercentageofROEforAnyIncentiveProject": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Percentage of ROE for Any Incentive Project",
        "label": "Loss Contingency, Percentage of ROE for Any Incentive Project",
        "terseLabel": "Percentage of ROE for any incentive project"
       }
      }
     },
     "localname": "LossContingencyPercentageofROEforAnyIncentiveProject",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_LossContingencyPeriodofComplaint": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Period of Complaint",
        "label": "Loss Contingency, Period of Complaint",
        "terseLabel": "Period of complaint"
       }
      }
     },
     "localname": "LossContingencyPeriodofComplaint",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_LossContingencySettlementAgreementCustomerAssistanceInitiatives": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Settlement Agreement, Customer Assistance Initiatives",
        "label": "Loss Contingency, Settlement Agreement, Customer Assistance Initiatives",
        "terseLabel": "Customer assistance initiatives"
       }
      }
     },
     "localname": "LossContingencySettlementAgreementCustomerAssistanceInitiatives",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_LossContingencySettlementAgreementCustomerCredits": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Settlement Agreement, Customer Credits",
        "label": "Loss Contingency, Settlement Agreement, Customer Credits",
        "terseLabel": "Customer credits"
       }
      }
     },
     "localname": "LossContingencySettlementAgreementCustomerCredits",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_LossContingencySettlementAgreementCustomerCreditsAndAssistance": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Settlement Agreement, Customer Credits And Assistance",
        "label": "Loss Contingency, Settlement Agreement, Customer Credits And Assistance",
        "terseLabel": "Customer credits and assistance"
       }
      }
     },
     "localname": "LossContingencySettlementAgreementCustomerCreditsAndAssistance",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_LossContingencyTotalAmountofDamagesAwarded": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loss Contingency, Total Amount of Damages Awarded",
        "label": "Loss Contingency, Total Amount of Damages Awarded",
        "terseLabel": "Total amount of damages awarded"
       }
      }
     },
     "localname": "LossContingencyTotalAmountofDamagesAwarded",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_LossesReclassifedFromRegAssetPreTax": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "he net gain (loss) previously recognized in regulatory assets that is a reclassification adjustment of other comprehensive income as a result of being recognized as a component of net periodic benefit cost for the period.",
        "label": "Losses Reclassifed From RegAsset PreTax",
        "terseLabel": "Actuarial Losses Reclassified as Net Periodic Benefit Expense"
       }
      }
     },
     "localname": "LossesReclassifedFromRegAssetPreTax",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_MarketableSecuritiesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Marketable Securities [Member]",
        "label": "Marketable Securities [Member]",
        "terseLabel": "Marketable Securities"
       }
      }
     },
     "localname": "MarketableSecuritiesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_MassachusettsDepartmentOfPublicUtilitiesDPUMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Massachusetts Department Of Public Utilities (DPU)",
        "label": "Massachusetts Department Of Public Utilities (DPU) [Member]",
        "terseLabel": "DPU"
       }
      }
     },
     "localname": "MassachusettsDepartmentOfPublicUtilitiesDPUMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_MassachusettsDepartmentOfPublicUtilitiesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Massachusetts Department of Public Utilities",
        "label": "Massachusetts Department of Public Utilities [Member]",
        "terseLabel": "Massachusetts Department of Public Utilities"
       }
      }
     },
     "localname": "MassachusettsDepartmentOfPublicUtilitiesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_MaterialsandSuppliesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Materials and Supplies [Member]",
        "label": "Materials and Supplies [Member]",
        "terseLabel": "Materials and Supplies"
       }
      }
     },
     "localname": "MaterialsandSuppliesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_MaximumLoansReceivableOutstanding": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Maximum Loans Receivable Outstanding",
        "label": "Maximum Loans Receivable Outstanding",
        "terseLabel": "Maximum loans receivable outstanding"
       }
      }
     },
     "localname": "MaximumLoansReceivableOutstanding",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTransferofEnergyEfficiencyLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_MeasurementInputCapacityPricesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measurement Input, Capacity Prices [Member]",
        "label": "Measurement Input, Capacity Prices [Member]",
        "terseLabel": "Capacity Prices"
       }
      }
     },
     "localname": "MeasurementInputCapacityPricesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_MeasurementInputForwardReserveMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measurement Input, Forward Reserve [Member]",
        "label": "Measurement Input, Forward Reserve [Member]",
        "terseLabel": "Forward Reserve"
       }
      }
     },
     "localname": "MeasurementInputForwardReserveMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_MgpSiteAccrualMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Portion of environmental liability associated with MGP sites",
        "label": "MGP Site accrual [Member]",
        "terseLabel": "MGP Site accrual"
       }
      }
     },
     "localname": "MgpSiteAccrualMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_MilestoneNuclearPowerStationMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Milestone Nuclear Power Station [Member]",
        "label": "Milestone Nuclear Power Station [Member]",
        "terseLabel": "Milestone Nuclear Power Station"
       }
      }
     },
     "localname": "MilestoneNuclearPowerStationMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_MillstoneNuclearPowerStationAndSeabrookNuclearPowerPlantMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Millstone Nuclear Power Station And Seabrook Nuclear Power Plant [Member]",
        "label": "Millstone Nuclear Power Station And Seabrook Nuclear Power Plant [Member]",
        "terseLabel": "Millstone Nuclear Power Station and Seabrook Nuclear Power Plant"
       }
      }
     },
     "localname": "MillstoneNuclearPowerStationAndSeabrookNuclearPowerPlantMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_MutualFundsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents investments in mutual and exchange traded funds",
        "label": "Mutual Funds [Member]",
        "terseLabel": "Mutual Funds and Equities"
       }
      }
     },
     "localname": "MutualFundsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_MyapcMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "MYAPC [Member]",
        "terseLabel": "MYAPC"
       }
      }
     },
     "localname": "MyapcMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_NSTARGas303SeriesUFirstMortgageBondsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "NSTAR Gas 3.03% Series U First Mortgage Bonds",
        "label": "NSTAR Gas 3.03% Series U First Mortgage Bonds [Member]",
        "terseLabel": "NSTAR Gas 3.03% Series U First Mortgage Bonds"
       }
      }
     },
     "localname": "NSTARGas303SeriesUFirstMortgageBondsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_NSTARGasCompanyMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "NSTAR Gas Company [Member]",
        "label": "NSTAR Gas Company [Member]",
        "terseLabel": "NSTAR Gas"
       }
      }
     },
     "localname": "NSTARGasCompanyMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_NaturalGasBusinessesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Natural Gas Businesses",
        "label": "Natural Gas Businesses [Member]",
        "terseLabel": "Natural Gas Businesses"
       }
      }
     },
     "localname": "NaturalGasBusinessesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_NaturalGasDistributionMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Natural Gas Distribution [Member]",
        "terseLabel": "Natural Gas Distribution",
        "verboseLabel": "Natural Gas Distribution"
       }
      }
     },
     "localname": "NaturalGasDistributionMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/GOODWILLNarrativeDetails",
      "http://www.eversource.com/role/GOODWILLSummaryofGoodwillbyReportableSegmentDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_NaturalGasInfrastructurePipelineOwnedByEnbridgeInc.Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Natural Gas Infrastructure - Pipeline Owned By Enbridge, Inc. [Member]",
        "label": "Natural Gas Infrastructure - Pipeline Owned By Enbridge, Inc. [Member]",
        "terseLabel": "Natural Gas Pipeline - Algonquin Gas Transmission, LLC"
       }
      }
     },
     "localname": "NaturalGasInfrastructurePipelineOwnedByEnbridgeInc.Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESSummaryofInvestmentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_NaturalGasProcurementContractsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Natural Gas Procurement Contracts [Member]",
        "terseLabel": "Natural Gas Procurement"
       }
      }
     },
     "localname": "NaturalGasProcurementContractsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_NaturalGasProcurementCostsIncurred": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Natural Gas Procurement Costs Incurred",
        "terseLabel": "Natural Gas Procurement"
       }
      }
     },
     "localname": "NaturalGasProcurementCostsIncurred",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofTotalCostsIncurredDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_NaturalGasTransitionServiceTransactionCosts": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Natural Gas Transition Service Transaction Costs",
        "label": "Natural Gas Transition Service Transaction Costs",
        "terseLabel": "Amount of natural gas transmission purchased"
       }
      }
     },
     "localname": "NaturalGasTransitionServiceTransactionCosts",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SEGMENTINFORMATIONNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_NonServiceCostBenefitsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non-Service Cost Benefits [Member]",
        "label": "Non-Service Cost Benefits [Member]",
        "verboseLabel": "Pension, SERP and PBOP Non-Service Income Components"
       }
      }
     },
     "localname": "NonServiceCostBenefitsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_NoncontrollingInterestIncreaseinContributionsFromParent": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Noncontrolling Interest, Increase in Contributions From Parent",
        "label": "Noncontrolling Interest, Increase in Contributions From Parent",
        "terseLabel": "Capital Contributions from Eversource Parent"
       }
      }
     },
     "localname": "NoncontrollingInterestIncreaseinContributionsFromParent",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_NortheastOffshoreLLCMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Northeast Offshore LLC",
        "label": "Northeast Offshore LLC [Member]",
        "terseLabel": "North East Offshore LLC"
       }
      }
     },
     "localname": "NortheastOffshoreLLCMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_NorthernPassTransmissionMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Northern Pass Transmission",
        "label": "Northern Pass Transmission [Member]",
        "terseLabel": "Northern Pass Transmission"
       }
      }
     },
     "localname": "NorthernPassTransmissionMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_NstarElectricCompanyMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "NSTAR Electric Company [Member]",
        "terseLabel": "NSTAR Electric Company",
        "verboseLabel": "NSTAR Electric Company"
       }
      }
     },
     "localname": "NstarElectricCompanyMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSNarrativeDetails",
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails",
      "http://www.eversource.com/role/AuditInformation",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEversourceandNSTARElectricBostonHarborCivilActionDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofNumberofSitesandReservesDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofReconciliationofActivityinEnvironmentalReserveDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofTotalCostsIncurredDetails",
      "http://www.eversource.com/role/COMMONSHARESCommonSharesAuthorizedandIssuedDetails",
      "http://www.eversource.com/role/COVERPAGE",
      "http://www.eversource.com/role/DIVIDENDRESTRICTIONSDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofCompensationExpenseandIncomeTaxBenefitDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofDefinedContributionPlansDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofFundedStatusDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofOtherRetirementBenefitsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails",
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails",
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESTaxCreditsandLossCarryforwardsDetails",
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails",
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails",
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails",
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails",
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails",
      "http://www.eversource.com/role/LONGTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETSParenthetical",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONNarrativeDetails",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAggregateCompositeDepreciationRatesDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/REVENUESNarrativeDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONNarrativeDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTScheduleofDebtDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAFUDCandWeightedAverageAFUDCDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSupplementalCashFlowInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_NumberofCompaniesThatTransmitHydroElectricity": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of Companies That Transmit Hydro Electricity",
        "label": "Number of Companies That Transmit Hydro Electricity",
        "terseLabel": "Number of companies that transmit hydro electricity imported from The Hydro-Quebec System in Canada"
       }
      }
     },
     "localname": "NumberofCompaniesThatTransmitHydroElectricity",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "es_NumberofElectricNaturalGasAndWaterCustomers": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of Electric, Natural Gas And Water Customers",
        "label": "Number of Electric, Natural Gas And Water Customers",
        "terseLabel": "Number of electric and natural gas customers"
       }
      }
     },
     "localname": "NumberofElectricNaturalGasAndWaterCustomers",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "es_NumberofRegulatedUtilities": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of Regulated Utilities",
        "label": "Number of Regulated Utilities",
        "terseLabel": "Number of regulated utilities"
       }
      }
     },
     "localname": "NumberofRegulatedUtilities",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "es_OffshoreWindBusinessNorthEastOffshoreAndBayStateWindMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Offshore Wind Business - North East Offshore And Bay State Wind [Member]",
        "label": "Offshore Wind Business - North East Offshore And Bay State Wind [Member]",
        "terseLabel": "Offshore Wind Business - North East Offshore"
       }
      }
     },
     "localname": "OffshoreWindBusinessNorthEastOffshoreAndBayStateWindMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails",
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESSummaryofInvestmentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_OtherAssetsAverageUsefulLife": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other Assets Average Useful Life",
        "label": "Other Assets Average Useful Life",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "OtherAssetsAverageUsefulLife",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_OtherEquityMethodInvestmentsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other Equity Method Investments [Member]",
        "label": "Other Equity Method Investments [Member]",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "OtherEquityMethodInvestmentsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESSummaryofInvestmentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_OtherIncomeNetTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Table Text Block] for Other Income, Net [Table]",
        "label": "Other Income, Net [Table Text Block]",
        "terseLabel": "Components of Other Income, Net"
       }
      }
     },
     "localname": "OtherIncomeNetTableTextBlock",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "es_OtherMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other [Member]",
        "label": "Other [Member]",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "OtherMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_OtherNet": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Other, Net",
        "terseLabel": "Other, Net"
       }
      }
     },
     "localname": "OtherNet",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_OtherRegulatoryAssetsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents various remaining other regulatory assets.",
        "label": "Other Regulatory Assets [Member]",
        "terseLabel": "Other Regulatory Assets"
       }
      }
     },
     "localname": "OtherRegulatoryAssetsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_OtherRegulatoryLiabilitiesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents various remaining other regulatory liabilities.",
        "label": "Other Regulatory Liabilities [Member]",
        "terseLabel": "Other Regulatory Liabilities"
       }
      }
     },
     "localname": "OtherRegulatoryLiabilitiesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_OtherRevenueAdjustmentsfromContractswithCustomersMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other Revenue Adjustments from Contracts with Customers [Member]",
        "label": "Other Revenue Adjustments from Contracts with Customers [Member]",
        "terseLabel": "Other Revenues from Contracts with Customers"
       }
      }
     },
     "localname": "OtherRevenueAdjustmentsfromContractswithCustomersMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_PaymentsForCharitableContributionsRelatedParties": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Payments For Charitable Contributions, Related Parties",
        "label": "Payments For Charitable Contributions, Related Parties",
        "terseLabel": "Charitable contributions"
       }
      }
     },
     "localname": "PaymentsForCharitableContributionsRelatedParties",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_PeakerCfdExpenseIncurred": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Peaker CfD Expense Incurred",
        "terseLabel": "Peaker CfDs"
       }
      }
     },
     "localname": "PeakerCfdExpenseIncurred",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofTotalCostsIncurredDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_PeakerContractsForDifferencesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Peaker Contracts For Differences [Member]",
        "terseLabel": "Peaker Contracts For Differences",
        "verboseLabel": "Peaker CfDs"
       }
      }
     },
     "localname": "PeakerContractsForDifferencesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_PensionAndOtherPostretirementDefinedBenefitPlansAssetsNoncurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 6.0,
       "parentTag": "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Pension And Other Postretirement Defined Benefit Plans Assets Noncurrent",
        "label": "Pension And Other Postretirement Defined Benefit Plans Assets Noncurrent",
        "terseLabel": "Prepaid Pension and PBOP"
       }
      }
     },
     "localname": "PensionAndOtherPostretirementDefinedBenefitPlansAssetsNoncurrent",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_PercentageofBaseROEofComplaintPeriod": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage of Base ROE of Complaint Period",
        "label": "Percentage of Base ROE of Complaint Period",
        "terseLabel": "Percentage of base ROE of complaint period"
       }
      }
     },
     "localname": "PercentageofBaseROEofComplaintPeriod",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_PercentageofCostsandBenefitsBorneUnderUnrecordedUnconditionalPurchaseObligation": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage of Costs and Benefits Borne Under Unrecorded Unconditional Purchase Obligation",
        "label": "Percentage of Costs and Benefits Borne Under Unrecorded Unconditional Purchase Obligation",
        "terseLabel": "Percentage of costs and benefits borne"
       }
      }
     },
     "localname": "PercentageofCostsandBenefitsBorneUnderUnrecordedUnconditionalPurchaseObligation",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_PercentageofCostsandBenefitsBorneUnderUnrecordedUnconditionalPurchaseObligationbyUnitedIlluminatedCompany": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage of Costs and Benefits Borne Under Unrecorded Unconditional Purchase Obligation by United Illuminated Company",
        "label": "Percentage of Costs and Benefits Borne Under Unrecorded Unconditional Purchase Obligation by United Illuminated Company",
        "terseLabel": "Percentage of costs and benefits borne by United Illuminated Company"
       }
      }
     },
     "localname": "PercentageofCostsandBenefitsBorneUnderUnrecordedUnconditionalPurchaseObligationbyUnitedIlluminatedCompany",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_PercentageofCostsorBenefitsBorneUnderCapacityRelatedContracts": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage of Costs or Benefits Borne Under Capacity-Related Contracts",
        "label": "Percentage of Costs or Benefits Borne Under Capacity-Related Contracts",
        "terseLabel": "Percentage of costs or benefits borne under capacity-related contracts (as a percentage)"
       }
      }
     },
     "localname": "PercentageofCostsorBenefitsBorneUnderCapacityRelatedContracts",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_PercentageofCostsorBenefitsBorneUnderCapacityRelatedContractsbyUnitedIlluminatedCompany": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage of Costs or Benefits Borne Under Capacity-Related Contracts by United Illuminated Company",
        "label": "Percentage of Costs or Benefits Borne Under Capacity-Related Contracts by United Illuminated Company",
        "terseLabel": "Percentage of costs or benefits borne under capacity-related contracts by United Illuminated Company (as a percentage)"
       }
      }
     },
     "localname": "PercentageofCostsorBenefitsBorneUnderCapacityRelatedContractsbyUnitedIlluminatedCompany",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_PercentageofExitPricePremiums": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage of Exit Price Premiums",
        "label": "Percentage of Exit Price Premiums",
        "terseLabel": "Percentage of exit price premiums related to derivative contracts"
       }
      }
     },
     "localname": "PercentageofExitPricePremiums",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_PercentageofTotalCapitalization": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage of Total Capitalization",
        "label": "Percentage of Total Capitalization",
        "terseLabel": "Total capitalization (as a percentage)"
       }
      }
     },
     "localname": "PercentageofTotalCapitalization",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "es_PeriodofAccountsReceivableRecoverableUnderFinancialorMedicalDuress": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period of Accounts Receivable Recoverable Under Financial or Medical Duress",
        "label": "Period of Accounts Receivable Recoverable Under Financial or Medical Duress",
        "terseLabel": "Period of accounts receivable recoverable under financial or medical duress"
       }
      }
     },
     "localname": "PeriodofAccountsReceivableRecoverableUnderFinancialorMedicalDuress",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_PeriodofGradedVestingScheduleUnderLongTermIncentiveProgram": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period of Graded Vesting Schedule Under Long-Term Incentive Program",
        "label": "Period of Graded Vesting Schedule Under Long-Term Incentive Program",
        "terseLabel": "Period of graded vesting schedule under long-term incentive program"
       }
      }
     },
     "localname": "PeriodofGradedVestingScheduleUnderLongTermIncentiveProgram",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_PeriodofMaturityRestrictingProvisionsofDebt": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period of Maturity Restricting Provisions of Debt",
        "label": "Period of Maturity Restricting Provisions of Debt",
        "terseLabel": "Period of maturity restricting provisions of debt"
       }
      }
     },
     "localname": "PeriodofMaturityRestrictingProvisionsofDebt",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_Post65PlanMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Post-65 Plan [Member]",
        "label": "Post-65 Plan [Member]",
        "terseLabel": "Post-65 Plan"
       }
      }
     },
     "localname": "Post65PlanMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Pre65PlanMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Pre-65 Plan [Member]",
        "label": "Pre-65 Plan [Member]",
        "terseLabel": "Pre-65 Plan"
       }
      }
     },
     "localname": "Pre65PlanMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_PriorServiceCostCreditArisingDuringPeriodRegulatoryAsset": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Prior Service Cost (Credit) Arising During Period, Regulatory Asset",
        "label": "Prior Service Cost (Credit) Arising During Period, Regulatory Asset",
        "terseLabel": "Prior Service Cost Arising During the Year"
       }
      }
     },
     "localname": "PriorServiceCostCreditArisingDuringPeriodRegulatoryAsset",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_ProceedsFromPaymentsForItemsRelatedToSpentNuclearFuel": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 9.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Proceeds From (Payments For) Items Related To Spent Nuclear Fuel",
        "label": "Proceeds From (Payments For) Items Related To Spent Nuclear Fuel",
        "terseLabel": "Payments Related to CYAPC's DOE Pre-1983 Spent Nuclear Fuel Obligation",
        "verboseLabel": "DOE settlement payment"
       }
      }
     },
     "localname": "ProceedsFromPaymentsForItemsRelatedToSpentNuclearFuel",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_ProceedsPaymentsOfIssuanceOfRateReductionBonds": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Proceeds (Payments) Of Issuance Of Rate Reduction Bonds",
        "label": "Proceeds (Payments) Of Issuance Of Rate Reduction Bonds",
        "terseLabel": "Repayment of Rate Reduction Bonds"
       }
      }
     },
     "localname": "ProceedsPaymentsOfIssuanceOfRateReductionBonds",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_PropertyPlantAndEquipmentNetExcludingConstructionWorkInProgress": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period end amount of property, plant and equipment (PPE) related to utility distribution.",
        "label": "Property Plant And Equipment Net Excluding Construction Work In Progress",
        "totalLabel": "Property, Plant and Equipment, Net"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentNetExcludingConstructionWorkInProgress",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_PublicServiceCompanyOfNewHampshirePSNHMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Public Service Company Of New Hampshire (PSNH) [Member]",
        "terseLabel": "Public Service Company of New Hampshire",
        "verboseLabel": "Public Service Company of New Hampshire"
       }
      }
     },
     "localname": "PublicServiceCompanyOfNewHampshirePSNHMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSNarrativeDetails",
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails",
      "http://www.eversource.com/role/AuditInformation",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofNumberofSitesandReservesDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofReconciliationofActivityinEnvironmentalReserveDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofTotalCostsIncurredDetails",
      "http://www.eversource.com/role/COMMONSHARESCommonSharesAuthorizedandIssuedDetails",
      "http://www.eversource.com/role/COVERPAGE",
      "http://www.eversource.com/role/DIVIDENDRESTRICTIONSDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofCompensationExpenseandIncomeTaxBenefitDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofDefinedContributionPlansDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofFundedStatusDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofOtherRetirementBenefitsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails",
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails",
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESTaxCreditsandLossCarryforwardsDetails",
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails",
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails",
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails",
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails",
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAggregateCompositeDepreciationRatesDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETSParenthetical",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESIncomeStatementDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESNarrativeDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONNarrativeDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAFUDCandWeightedAverageAFUDCDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofOperatingExpensesDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSupplementalCashFlowInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_PublicUtilitiesApprovedRate": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Public Utilities, Approved Rate",
        "label": "Public Utilities, Approved Rate",
        "terseLabel": "Approved rate base"
       }
      }
     },
     "localname": "PublicUtilitiesApprovedRate",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_PublicUtilitiesPropertyPlantAndEquipmentDistributionNaturalGas": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails": {
       "order": 2.0,
       "parentTag": "es_PublicUtilitiesPropertyPlantAndEquipmentElectricNaturalGasandWaterUtilityTotal",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period end amount of property, plant and equipment (PPE) related to utility natural gas distribution.",
        "label": "Public Utilities Property Plant And Equipment Distribution Natural Gas",
        "terseLabel": "Distribution - Natural Gas"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantAndEquipmentDistributionNaturalGas",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_PublicUtilitiesPropertyPlantAndEquipmentDistributionWater": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails": {
       "order": 4.0,
       "parentTag": "es_PublicUtilitiesPropertyPlantAndEquipmentElectricNaturalGasandWaterUtilityTotal",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Public Utilities Property Plant And Equipment Distribution, Water",
        "label": "Public Utilities Property Plant And Equipment Distribution, Water",
        "terseLabel": "Distribution - Water"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantAndEquipmentDistributionWater",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_PublicUtilitiesPropertyPlantAndEquipmentElectricNaturalGasandWaterUtilityTotal": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Public Utilities Property Plant And Equipment Electric Natural Gas and Water Utility Total",
        "label": "Public Utilities Property Plant And Equipment Electric Natural Gas and Water Utility Total",
        "totalLabel": "Utility"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantAndEquipmentElectricNaturalGasandWaterUtilityTotal",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_PublicUtilitiesPropertyPlantandEquipmentAccumulatedDepreciationElectricNaturalGasandWaterUtility": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Public Utilities, Property, Plant and Equipment, Accumulated Depreciation, Electric, Natural Gas and Water Utility",
        "label": "Public Utilities, Property, Plant and Equipment, Accumulated Depreciation, Electric, Natural Gas and Water Utility",
        "negatedTerseLabel": "Utility"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantandEquipmentAccumulatedDepreciationElectricNaturalGasandWaterUtility",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_PublicUtilitiesPropertyPlantandEquipmentAccumulatedDepreciationOther": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Public Utilities, Property, Plant and Equipment, Accumulated Depreciation, Other",
        "label": "Public Utilities, Property, Plant and Equipment, Accumulated Depreciation, Other",
        "negatedTerseLabel": "Other"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantandEquipmentAccumulatedDepreciationOther",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_PublicUtilitiesRateMattersGainLossOnRateChange": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Public Utilities, Rate Matters, Gain (Loss) On Rate Change",
        "label": "Public Utilities, Rate Matters, Gain (Loss) On Rate Change",
        "terseLabel": "Pre-tax benefit to earnings from settlement agreement"
       }
      }
     },
     "localname": "PublicUtilitiesRateMattersGainLossOnRateChange",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_PurchaseGuaranteeExpiring2026Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Purchase Guarantee Expiring 2026",
        "label": "Purchase Guarantee Expiring 2026 [Member]",
        "terseLabel": "Purchase Guarantee Expiring 2026"
       }
      }
     },
     "localname": "PurchaseGuaranteeExpiring2026Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_PurchaseGuaranteeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Purchase Guarantee",
        "label": "Purchase Guarantee [Member]",
        "terseLabel": "Construction-related Purchase Contracts with Third-Party Suppliers"
       }
      }
     },
     "localname": "PurchaseGuaranteeMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_RateReductionBonds": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 4.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate Reduction Bonds",
        "label": "Rate Reduction Bonds",
        "terseLabel": "Rate Reduction Bonds",
        "verboseLabel": "Rate Reduction Bonds - Long-Term Portion"
       }
      }
     },
     "localname": "RateReductionBonds",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RateReductionBondsCurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 3.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate Reduction Bonds, Current",
        "label": "Rate Reduction Bonds, Current",
        "terseLabel": "Rate Reduction Bonds \u2013 Current Portion",
        "verboseLabel": "Rate Reduction Bonds - Current Portion"
       }
      }
     },
     "localname": "RateReductionBondsCurrent",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RateReductionBondsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate Reduction Bonds [Member]",
        "label": "Rate Reduction Bonds [Member]",
        "terseLabel": "Rate Reduction Bonds"
       }
      }
     },
     "localname": "RateReductionBondsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESIncomeStatementDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESNarrativeDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_RateReductionBondsPrincipalAndInterestPaymentsToBePaid": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate Reduction Bonds, Principal And Interest Payments To Be Paid",
        "label": "Rate Reduction Bonds, Principal And Interest Payments To Be Paid",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "RateReductionBondsPrincipalAndInterestPaymentsToBePaid",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RateReductionBondsPrincipalAndInterestPaymentsToBePaidAfterYearFive": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails": {
       "order": 6.0,
       "parentTag": "es_RateReductionBondsPrincipalAndInterestPaymentsToBePaid",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate Reduction Bonds, Principal And Interest Payments To Be Paid, After Year Five",
        "label": "Rate Reduction Bonds, Principal And Interest Payments To Be Paid, After Year Five",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "RateReductionBondsPrincipalAndInterestPaymentsToBePaidAfterYearFive",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RateReductionBondsPrincipalAndInterestPaymentsToBePaidYearFive": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails": {
       "order": 5.0,
       "parentTag": "es_RateReductionBondsPrincipalAndInterestPaymentsToBePaid",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate Reduction Bonds, Principal And Interest Payments To Be Paid, Year Five",
        "label": "Rate Reduction Bonds, Principal And Interest Payments To Be Paid, Year Five",
        "terseLabel": "2026"
       }
      }
     },
     "localname": "RateReductionBondsPrincipalAndInterestPaymentsToBePaidYearFive",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RateReductionBondsPrincipalAndInterestPaymentsToBePaidYearFour": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails": {
       "order": 4.0,
       "parentTag": "es_RateReductionBondsPrincipalAndInterestPaymentsToBePaid",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate Reduction Bonds, Principal And Interest Payments To Be Paid, Year Four",
        "label": "Rate Reduction Bonds, Principal And Interest Payments To Be Paid, Year Four",
        "terseLabel": "2025"
       }
      }
     },
     "localname": "RateReductionBondsPrincipalAndInterestPaymentsToBePaidYearFour",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RateReductionBondsPrincipalAndInterestPaymentsToBePaidYearOne": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails": {
       "order": 1.0,
       "parentTag": "es_RateReductionBondsPrincipalAndInterestPaymentsToBePaid",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate Reduction Bonds, Principal And Interest Payments To Be Paid, Year One",
        "label": "Rate Reduction Bonds, Principal And Interest Payments To Be Paid, Year One",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "RateReductionBondsPrincipalAndInterestPaymentsToBePaidYearOne",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RateReductionBondsPrincipalAndInterestPaymentsToBePaidYearThree": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails": {
       "order": 3.0,
       "parentTag": "es_RateReductionBondsPrincipalAndInterestPaymentsToBePaid",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate Reduction Bonds, Principal And Interest Payments To Be Paid, Year Three",
        "label": "Rate Reduction Bonds, Principal And Interest Payments To Be Paid, Year Three",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "RateReductionBondsPrincipalAndInterestPaymentsToBePaidYearThree",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RateReductionBondsPrincipalAndInterestPaymentsToBePaidYearTwo": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails": {
       "order": 2.0,
       "parentTag": "es_RateReductionBondsPrincipalAndInterestPaymentsToBePaid",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate Reduction Bonds, Principal And Interest Payments To Be Paid, Year Two",
        "label": "Rate Reduction Bonds, Principal And Interest Payments To Be Paid, Year Two",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "RateReductionBondsPrincipalAndInterestPaymentsToBePaidYearTwo",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESRateReductionBondsPrincipalandInterestPaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RateReductionBondsandVariableInterestEntityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate Reduction Bonds and Variable Interest Entity [Abstract]",
        "label": "Rate Reduction Bonds and Variable Interest Entity [Abstract]",
        "terseLabel": "Rate Reduction Bonds and Variable Interest Entity [Abstract]"
       }
      }
     },
     "localname": "RateReductionBondsandVariableInterestEntityAbstract",
     "nsuri": "http://www.eversource.com/20211231",
     "xbrltype": "stringItemType"
    },
    "es_RateReductionBondsandVariableInterestEntityDisclosureTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate Reduction Bonds and Variable Interest Entity Disclosure [Text Block]",
        "label": "Rate Reduction Bonds and Variable Interest Entity Disclosure [Text Block]",
        "verboseLabel": "RATE REDUCTION BONDS AND VARIABLE INTEREST ENTITIES"
       }
      }
     },
     "localname": "RateReductionBondsandVariableInterestEntityDisclosureTextBlock",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIES"
     ],
     "xbrltype": "textBlockItemType"
    },
    "es_RealEstatePurchaseGuaranteeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Real Estate Purchase Guarantee",
        "label": "Real Estate Purchase Guarantee [Member]",
        "terseLabel": "Real Estate Purchase"
       }
      }
     },
     "localname": "RealEstatePurchaseGuaranteeMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_RecoveryOfCumulativeUnderRecovery": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Recovery Of Cumulative Under-Recovery",
        "label": "Recovery Of Cumulative Under-Recovery",
        "terseLabel": "Recovery of cumulative under-recoveries"
       }
      }
     },
     "localname": "RecoveryOfCumulativeUnderRecovery",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RecsMemberMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Renewable Energy Credits inventory",
        "label": "RECs [Member]",
        "terseLabel": "RECs"
       }
      }
     },
     "localname": "RecsMemberMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_RegulatoryAssetPriorServiceCost": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount related to the pretax cost of benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation, which has not yet been recognized as components of net periodic benefit cost.",
        "label": "Regulatory Asset Prior Service Cost",
        "terseLabel": "Prior Service Cost"
       }
      }
     },
     "localname": "RegulatoryAssetPriorServiceCost",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RegulatoryAssetRemainingAmortizationPeriod": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Regulatory Asset, Remaining Amortization Period",
        "label": "Regulatory Asset, Remaining Amortization Period",
        "terseLabel": "Remaining amortization"
       }
      }
     },
     "localname": "RegulatoryAssetRemainingAmortizationPeriod",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_RegulatoryAssetsOffsettingDerivativeLiabilitiesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The regulatory assets offsetting derivative liabilities relate to the fair value of contracts used to purchase power and other related contracts that will be collected from customers in the future.",
        "label": "Regulatory Assets Offsetting Derivative Liabilities [Member]",
        "terseLabel": "Derivative Liabilities"
       }
      }
     },
     "localname": "RegulatoryAssetsOffsettingDerivativeLiabilitiesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_RegulatoryAssetsRemovalCostsIncome": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 20.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Regulatory Assets, Removal Costs (Income)",
        "label": "Regulatory Assets, Removal Costs (Income)",
        "negatedTerseLabel": "Cost of Removal Expenditures"
       }
      }
     },
     "localname": "RegulatoryAssetsRemovalCostsIncome",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RegulatoryTrackerDeferralsRegulatoryAssetsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Regulatory tracker deferrals are approved rate mechanisms that allow utilities to recover costs in specific business segments through reconcilable tracking mechanisms that are reviewed at least annually by the applicable regulatory commission. Regulatory tracker deferrals are recorded as regulatory assets if unrecovered costs are in excess of collections and are recorded as regulatory liabilities if collections are in excess of costs.",
        "label": "Regulatory Tracker Deferrals Regulatory Assets [Member]",
        "verboseLabel": "Regulatory Tracker Mechanisms"
       }
      }
     },
     "localname": "RegulatoryTrackerDeferralsRegulatoryAssetsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_RegulatoryTrackerDeferralsRegulatoryLiabilitiesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Regulatory tracker deferrals are approved rate mechanisms that allow utilities to recover costs in specific business segments through reconcilable tracking mechanisms that are reviewed at least annually by the applicable regulatory commission. Regulatory tracker deferrals are recorded as regulatory assets if unrecovered costs are in excess of collections and are recorded as regulatory liabilities if collections are in excess of costs.",
        "label": "Regulatory Tracker Deferrals Regulatory Liabilities [Member]",
        "terseLabel": "Regulatory Tracker Mechanisms"
       }
      }
     },
     "localname": "RegulatoryTrackerDeferralsRegulatoryLiabilitiesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Regulatoryassetgainslossesbeforetax": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The pretax net amount of gains and losses that are not yet recognized as a component of net periodic benefit cost, and that are recognized as increases or decreases in other comprehensive income as they arise. Gains and losses are due to changes in the value of either the benefit obligation or the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption, or the consequence of a decision to temporarily deviate from the substantive plan.",
        "label": "RegulatoryAsset Gains Losses Before Tax",
        "terseLabel": "Actuarial Loss"
       }
      }
     },
     "localname": "Regulatoryassetgainslossesbeforetax",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RelatedIntercompanyAllocationsofDefinedBenefitExpense": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount represents allocation of pension and other post retirement benefits expense from parent and other that are not included in pension and post-retirement benefit expense.",
        "label": "Related Intercompany Allocations of Defined (Benefit) Expense",
        "terseLabel": "Intercompany Expense/(Income) Allocations"
       }
      }
     },
     "localname": "RelatedIntercompanyAllocationsofDefinedBenefitExpense",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RelatedPartyPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Related Party [Policy Text Block]",
        "label": "Related Party [Policy Text Block]",
        "terseLabel": "Related Parties"
       }
      }
     },
     "localname": "RelatedPartyPolicyTextBlock",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "es_RenewableEnergyContractsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Renewable Energy Contracts [Member]",
        "terseLabel": "Renewable Energy"
       }
      }
     },
     "localname": "RenewableEnergyContractsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_RenewableEnergyCostsIncurred": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Renewable Energy Costs Incurred",
        "terseLabel": "Renewable Energy"
       }
      }
     },
     "localname": "RenewableEnergyCostsIncurred",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofTotalCostsIncurredDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_RenewableEnergyFundInvestmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Renewable Energy Fund Investment",
        "label": "Renewable Energy Fund Investment [Member]",
        "terseLabel": "Renewable Energy Fund"
       }
      }
     },
     "localname": "RenewableEnergyFundInvestmentMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_RenewableEnergyInvestmentFundMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Renewable Energy Investment Fund [Member]",
        "label": "Renewable Energy Investment Fund [Member]",
        "terseLabel": "Renewable Energy Investment Fund"
       }
      }
     },
     "localname": "RenewableEnergyInvestmentFundMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESSummaryofInvestmentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_RenewablePortfolioStandardsComplianceObligation": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 11.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The current obligation PSNH has in order to meet renewable compliance standards.",
        "label": "Renewable Portfolio Standards Compliance Obligation",
        "terseLabel": "Renewable Portfolio Standards Compliance Obligations"
       }
      }
     },
     "localname": "RenewablePortfolioStandardsComplianceObligation",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_ReservesForRevenuesSubjectToRefundMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Reserves For Revenues Subject To Refund",
        "label": "Reserves For Revenues Subject To Refund [Member]",
        "terseLabel": "Reserve for Revenues Subject to Refund"
       }
      }
     },
     "localname": "ReservesForRevenuesSubjectToRefundMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REVENUESNarrativeDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_ResidentialMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Residential [Member]",
        "label": "Residential [Member]",
        "terseLabel": "Residential"
       }
      }
     },
     "localname": "ResidentialMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_RetailNonHardshipWholesaleandOtherReceivablesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Retail Non Hardship Wholesaleand Other Receivables",
        "label": "Retail Non Hardship Wholesaleand Other Receivables [Member]",
        "terseLabel": "Retail Non Hardship Wholesaleand Other Receivables"
       }
      }
     },
     "localname": "RetailNonHardshipWholesaleandOtherReceivablesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_RevolutionWindAndSouthForkWindMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Revolution Wind And South Fork Wind [Member]",
        "label": "Revolution Wind And South Fork Wind [Member]",
        "terseLabel": "Revolution Wind And South Fork Wind"
       }
      }
     },
     "localname": "RevolutionWindAndSouthForkWindMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_RevolutionWindLLCMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Revolution Wind, LLC",
        "label": "Revolution Wind, LLC [Member]",
        "terseLabel": "Revolution Wind, LLC"
       }
      }
     },
     "localname": "RevolutionWindLLCMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_RockyRiverRealtyCompanyAndEversourceServiceMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rocky River Realty Company And Eversource Service",
        "label": "Rocky River Realty Company And Eversource Service [Member]",
        "terseLabel": "Eversource Service"
       }
      }
     },
     "localname": "RockyRiverRealtyCompanyAndEversourceServiceMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_ScheduleOfAllowanceForFundsUsedDuringConstructionTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Schedule Of Allowance For Funds Used During Construction [Table Text Block]",
        "terseLabel": "Weighted-Average AFUDC Rates"
       }
      }
     },
     "localname": "ScheduleOfAllowanceForFundsUsedDuringConstructionTableTextBlock",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "es_ScheduleOfDefinedContributionPlans401kTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule disclosing the matching contributions of cash and NU common shares to the 401k plan.",
        "label": "Schedule Of Defined Contribution Plans 401k [Table Text Block]",
        "terseLabel": "Schedule of Defined Contribution Plans"
       }
      }
     },
     "localname": "ScheduleOfDefinedContributionPlans401kTableTextBlock",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "es_ScheduleOfFuelCostsTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Schedule of Fuel Costs [Table Text Block]",
        "terseLabel": "Costs Related to Fuel and Natural Gas"
       }
      }
     },
     "localname": "ScheduleOfFuelCostsTableTextBlock",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "es_ScheduleOfRateReductionBondsPrincipalAndInterestPaymentsTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule Of Rate Reduction Bonds, Principal And Interest Payments",
        "label": "Schedule Of Rate Reduction Bonds, Principal And Interest Payments [Table Text Block]",
        "terseLabel": "Schedule Of Rate Reduction Bonds, Principal And Interest Payments"
       }
      }
     },
     "localname": "ScheduleOfRateReductionBondsPrincipalAndInterestPaymentsTableTextBlock",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "es_ScheduleofAssetRetirementObligationLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Line Items] for Schedule of Asset Retirement Obligation [Table]",
        "label": "Schedule of Asset Retirement Obligation [Line Items]",
        "terseLabel": "Schedule of Asset Retirement Obligation [Line Items]"
       }
      }
     },
     "localname": "ScheduleofAssetRetirementObligationLineItems",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSNarrativeDetails",
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_ScheduleofAssetRetirementObligationTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule of Asset Retirement Obligation [Table]",
        "label": "Schedule of Asset Retirement Obligation [Table]",
        "terseLabel": "Schedule of Asset Retirement Obligation [Table]"
       }
      }
     },
     "localname": "ScheduleofAssetRetirementObligationTable",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSNarrativeDetails",
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_ScheduleofGrossEarningsTaxesTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule of Gross Earnings Taxes [Table Text Block]",
        "label": "Schedule of Gross Earnings Taxes [Table Text Block]",
        "terseLabel": "Other Taxes"
       }
      }
     },
     "localname": "ScheduleofGrossEarningsTaxesTableTextBlock",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "es_ScheduleofRestrictionsonRetainedEarningsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Line Items] for Schedule of Restrictions on Retained Earnings [Table]",
        "label": "Schedule of Restrictions on Retained Earnings [Line Items]",
        "terseLabel": "Schedule of Restrictions on Retained Earnings [Line Items]"
       }
      }
     },
     "localname": "ScheduleofRestrictionsonRetainedEarningsLineItems",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/DIVIDENDRESTRICTIONSDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_ScheduleofRestrictionsonRetainedEarningsTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule of Restrictions on Retained Earnings [Table]",
        "label": "Schedule of Restrictions on Retained Earnings [Table]",
        "terseLabel": "Schedule of Restrictions on Retained Earnings [Table]"
       }
      }
     },
     "localname": "ScheduleofRestrictionsonRetainedEarningsTable",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/DIVIDENDRESTRICTIONSDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_ScheduleofSupplementalCashFlowLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Line Items] for Schedule of Supplemental Cash Flow [Table]",
        "label": "Schedule of Supplemental Cash Flow [Line Items]",
        "terseLabel": "Schedule of Supplemental Cash Flow [Line Items]"
       }
      }
     },
     "localname": "ScheduleofSupplementalCashFlowLineItems",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSupplementalCashFlowInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_ScheduleofSupplementalCashFlowTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule of Supplemental Cash Flow [Table]",
        "label": "Schedule of Supplemental Cash Flow [Table]",
        "terseLabel": "Schedule of Supplemental Cash Flow [Table]"
       }
      }
     },
     "localname": "ScheduleofSupplementalCashFlowTable",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSupplementalCashFlowInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_SeabrookNuclearPowerPlantMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Seabrook Nuclear Power Plant [Member]",
        "label": "Seabrook Nuclear Power Plant [Member]",
        "terseLabel": "Seabrook Nuclear Power Plant"
       }
      }
     },
     "localname": "SeabrookNuclearPowerPlantMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SecuredDebtNotesDue20222044Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Secured Debt Notes Due 2022 - 2044",
        "label": "Secured Debt Notes Due 2022 - 2044 [Member]",
        "terseLabel": "Aquarion - Secured Debt 1.296% - 9.290% due 2022 - 2044"
       }
      }
     },
     "localname": "SecuredDebtNotesDue20222044Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeniorNotesDue2024Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Senior Notes Due 2024 [Member]",
        "label": "Senior Notes Due 2024 [Member]",
        "terseLabel": "Aquarion - Senior Notes 4.000% due 2024"
       }
      }
     },
     "localname": "SeniorNotesDue2024Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesA2006NotesDue2036Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series A 2006 Notes Due 2036 [Member]",
        "label": "Series A 2006 Notes Due 2036 [Member]",
        "terseLabel": "6.350% 2006 Series A due 2036"
       }
      }
     },
     "localname": "SeriesA2006NotesDue2036Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesA2013NotesDue2023Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series A 2013 Notes Due 2023 [Member]",
        "label": "Series A 2013 Notes Due 2023 [Member]",
        "terseLabel": "2.500% 2013 Series A due 2023"
       }
      }
     },
     "localname": "SeriesA2013NotesDue2023Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesA2014NotesDue2044Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series A 2014 Notes Due 2044 [Member]",
        "label": "Series A 2014 Notes Due 2044 [Member]",
        "terseLabel": "4.300% 2014 Series A due 2044"
       }
      }
     },
     "localname": "SeriesA2014NotesDue2044Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesA2015NotesDue2045Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series A 2015 Notes Due 2045 [Member]",
        "label": "Series A 2015 Notes Due 2045 [Member]",
        "terseLabel": "4.150% 2015 Series A due 2045"
       }
      }
     },
     "localname": "SeriesA2015NotesDue2045Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesA2017NotesDue2027Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series A 2017 Notes Due 2027 [Member]",
        "label": "Series A 2017 Notes Due 2027 [Member]",
        "terseLabel": "3.200% 2017 Series A due 2027"
       }
      }
     },
     "localname": "SeriesA2017NotesDue2027Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesA2018NotesDue2048Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series A 2018 Notes Due 2048 [Member]",
        "label": "Series A 2018 Notes Due 2048 [Member]",
        "terseLabel": "4.000% 2018 Series A due 2048"
       }
      }
     },
     "localname": "SeriesA2018NotesDue2048Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesA2020NotesDue2025Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series A 2020 Notes Due 2025",
        "label": "Series A 2020 Notes Due 2025 [Member]",
        "terseLabel": "0.750% 2020 Series A due 2025"
       }
      }
     },
     "localname": "SeriesA2020NotesDue2025Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesA2021NotesDue2031Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series A 2021 Notes Due 2031",
        "label": "Series A 2021 Notes Due 2031 [Member]",
        "terseLabel": "2.050% 2021 Series A due 2031"
       }
      }
     },
     "localname": "SeriesA2021NotesDue2031Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesB2004NotesDue2034Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series B 2004 Notes Due 2034 [Member]",
        "label": "Series B 2004 Notes Due 2034 [Member]",
        "terseLabel": "5.750% 2004 Series B due 2034"
       }
      }
     },
     "localname": "SeriesB2004NotesDue2034Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesB2005NotesDue2035Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series B 2005 Notes Due 2035 [Member]",
        "label": "Series B 2005 Notes Due 2035 [Member]",
        "terseLabel": "5.625% 2005 Series B due 2035"
       }
      }
     },
     "localname": "SeriesB2005NotesDue2035Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesB2007NotesDue2037Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series B 2007 Notes Due 2037 [Member]",
        "label": "Series B 2007 Notes Due 2037 [Member]",
        "terseLabel": "5.750% 2007 Series B due 2037"
       }
      }
     },
     "localname": "SeriesB2007NotesDue2037Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesBNotesDue2034Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series B Notes Due 2034 [Member]",
        "label": "Series B Notes Due 2034 [Member]",
        "terseLabel": "5.900% Senior Notes Series B due 2034"
       }
      }
     },
     "localname": "SeriesBNotesDue2034Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesD1994NotesDue2024Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series D 1994 Notes Due 2024 [Member]",
        "label": "Series D 1994 Notes Due 2024 [Member]",
        "terseLabel": "7.875% 1994 Series D due 2024"
       }
      }
     },
     "localname": "SeriesD1994NotesDue2024Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesD2007NotesDue2037Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series D 2007 Notes Due 2037 [Member]",
        "label": "Series D 2007 Notes Due 2037 [Member]",
        "terseLabel": "6.375% 2007 Series D due 2037"
       }
      }
     },
     "localname": "SeriesD2007NotesDue2037Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesDNotesDue2037Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series D Notes Due 2037 [Member]",
        "label": "Series D Notes Due 2037 [Member]",
        "terseLabel": "6.700% Senior Notes Series D due 2037"
       }
      }
     },
     "localname": "SeriesDNotesDue2037Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesE1954PreferredStockat2.06Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series E 1954 Preferred Stock at $2.06 [Member]",
        "label": "Series E 1954 Preferred Stock at $2.06 [Member]",
        "terseLabel": "Series E of 1954 Preferred Stock at $2.06"
       }
      }
     },
     "localname": "SeriesE1954PreferredStockat2.06Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesFNotesDue2021Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series F Notes Due 2021 [Member]",
        "label": "Series F Notes Due 2021 [Member]",
        "terseLabel": "3.500% Senior Notes Series F due 2021"
       }
      }
     },
     "localname": "SeriesFNotesDue2021Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesFof1955PreferredStockat2.09Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series F of 1955 Preferred Stock at $2.09 [Member]",
        "label": "Series F of 1955 Preferred Stock at $2.09 [Member]",
        "terseLabel": "Series F of 1955 Preferred Stock at $2.09"
       }
      }
     },
     "localname": "SeriesFof1955PreferredStockat2.09Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesGNotesDue2023Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series G Notes Due 2023 [Member]",
        "label": "Series G Notes Due 2023 [Member]",
        "terseLabel": "3.880% Senior Notes Series G due 2023"
       }
      }
     },
     "localname": "SeriesGNotesDue2023Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesGof1968PreferredStockat3.24Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series G of 1968 Preferred Stock at $3.24 [Member]",
        "label": "Series G of 1968 Preferred Stock at $3.24 [Member]",
        "terseLabel": "Series G of 1968 Preferred Stock at $3.24"
       }
      }
     },
     "localname": "SeriesGof1968PreferredStockat3.24Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesHNotesDue2026Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series H Notes Due 2026 [Member]",
        "label": "Series H Notes Due 2026 [Member]",
        "terseLabel": "2.750% Senior Notes Series H due 2026"
       }
      }
     },
     "localname": "SeriesHNotesDue2026Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesMNotesDue2035Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series M Notes Due 2035 [Member]",
        "label": "Series M Notes Due 2035 [Member]",
        "terseLabel": "5.600% Series M due 2035"
       }
      }
     },
     "localname": "SeriesMNotesDue2035Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesQNotesDue2021Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series Q Notes Due 2021 [Member]",
        "label": "Series Q Notes Due 2021 [Member]",
        "terseLabel": "4.050% Series Q due 2021"
       }
      }
     },
     "localname": "SeriesQNotesDue2021Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesRNotesDue2021Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series R Notes Due 2021 [Member]",
        "label": "Series R Notes Due 2021 [Member]",
        "terseLabel": "3.200% Series R due 2021"
       }
      }
     },
     "localname": "SeriesRNotesDue2021Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesSNotesDue2023Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series S Notes Due 2023 [Member]",
        "label": "Series S Notes Due 2023 [Member]",
        "terseLabel": "3.500% Series S due 2023"
       }
      }
     },
     "localname": "SeriesSNotesDue2023Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesTNotesDue2049Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series T Notes Due 2049 [Member]",
        "label": "Series T Notes Due 2049 [Member]",
        "terseLabel": "3.600% Series T due 2049"
       }
      }
     },
     "localname": "SeriesTNotesDue2049Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Seriesof1947PreferredStockat1.90Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series of 1947 Preferred Stock at $1.90 [Member]",
        "label": "Series of 1947 Preferred Stock at $1.90 [Member]",
        "terseLabel": "Series of 1947 Preferred Stock at $1.90"
       }
      }
     },
     "localname": "Seriesof1947PreferredStockat1.90Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Seriesof1947PreferredStockat2.00Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series of 1947 Preferred Stock at $2.00 [Member]",
        "label": "Series of 1947 Preferred Stock at $2.00 [Member]",
        "terseLabel": "Series of 1947 Preferred Stock at $2.00"
       }
      }
     },
     "localname": "Seriesof1947PreferredStockat2.00Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Seriesof1949PreferredStockat2.04Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series of 1949 Preferred Stock at $2.04 [Member]",
        "label": "Series of 1949 Preferred Stock at $2.04 [Member]",
        "terseLabel": "Series of 1949 Preferred Stock at $2.04"
       }
      }
     },
     "localname": "Seriesof1949PreferredStockat2.04Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Seriesof1949PreferredStockat2.20Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series of 1949 Preferred Stock at $2.20 [Member]",
        "label": "Series of 1949 Preferred Stock at $2.20 [Member]",
        "terseLabel": "Series of 1949 Preferred Stock at $2.20"
       }
      }
     },
     "localname": "Seriesof1949PreferredStockat2.20Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Seriesof1949PreferredStockat3.90Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series of 1949 Preferred Stock at 3.90% [Member]",
        "label": "Series of 1949 Preferred Stock at 3.90% [Member]",
        "terseLabel": "Series of 1949 Preferred Stock at 3.90%"
       }
      }
     },
     "localname": "Seriesof1949PreferredStockat3.90Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Seriesof1956PreferredStockat4.5Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series of 1956 Preferred Stock at 4.5% [Member]",
        "label": "Series of 1956 Preferred Stock at 4.5% [Member]",
        "terseLabel": "Series of 1956 Preferred Stock at 4.5%"
       }
      }
     },
     "localname": "Seriesof1956PreferredStockat4.5Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Seriesof1958PreferredStockat4.96Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series of 1958 Preferred Stock at 4.96% [Member]",
        "label": "Series of 1958 Preferred Stock at 4.96% [Member]",
        "terseLabel": "Series of 1958 Preferred Stock at 4.96%"
       }
      }
     },
     "localname": "Seriesof1958PreferredStockat4.96Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Seriesof1963PreferredStockat4.5Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series of 1963 Preferred Stock at 4.5% [Member]",
        "label": "Series of 1963 Preferred Stock at 4.5% [Member]",
        "terseLabel": "Series of 1963 Preferred Stock at 4.5%"
       }
      }
     },
     "localname": "Seriesof1963PreferredStockat4.5Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Seriesof1967PreferredStockat5.28Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series of 1967 Preferred Stock at 5.28% [Member]",
        "label": "Series of 1967 Preferred Stock at 5.28% [Member]",
        "terseLabel": "Series of 1967 Preferred Stock at 5.28%"
       }
      }
     },
     "localname": "Seriesof1967PreferredStockat5.28Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Seriesof1968PreferredStockat6.56Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series of 1968 Preferred Stock at 6.56% [Member]",
        "label": "Series of 1968 Preferred Stock at 6.56% [Member]",
        "terseLabel": "Series of 1968 Preferred Stock at 6.56%"
       }
      }
     },
     "localname": "Seriesof1968PreferredStockat6.56Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesofPreferredStockat4.25Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series of Preferred Stock at 4.25% [Member]",
        "label": "Series of Preferred Stock at 4.25% [Member]",
        "terseLabel": "Preferred Stock 4.25%"
       }
      }
     },
     "localname": "SeriesofPreferredStockat4.25Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesofPreferredStockat4.78Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series of Preferred Stock at 4.78% [Member]",
        "label": "Series of Preferred Stock at 4.78% [Member]",
        "terseLabel": "Preferred Stock 4.78%"
       }
      }
     },
     "localname": "SeriesofPreferredStockat4.78Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SeriesofPreferredStockat6Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Series of Preferred Stock at 6% [Member]",
        "label": "Series of Preferred Stock at 6% [Member]",
        "terseLabel": "Series of Preferred Stock at 6%"
       }
      }
     },
     "localname": "SeriesofPreferredStockat6Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsIssuedInPeriodWeightedAverageGrantDateFairValue": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The weighted average grant-date fair value of the number of shares newly issued during the reporting period under the plan.",
        "label": "Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Issued In Period Weighted Average Grant Date Fair Value",
        "verboseLabel": "Shares issued (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsIssuedInPeriodWeightedAverageGrantDateFairValue",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "es_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpectedToVest": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "As of the balance sheet date, the number of shares into which expected to vest awards outstanding can be converted under the option plan.",
        "label": "Share Based Compensation Arrangement By Share Based Payment Award Expected To Vest",
        "terseLabel": "Additional restricted stock unit expected to vest (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardExpectedToVest",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "es_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestedOutstandingNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Share Based Compensation Arrangement By Share Based Payment Award Vested Outstanding Number",
        "terseLabel": "Restricted stock unit fully vested (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardVestedOutstandingNumber",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "es_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsNonvestedandVestedNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested and Vested, Number",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested and Vested, Number",
        "periodEndLabel": "Ending balance (in shares)",
        "periodStartLabel": "Beginning balance (in shares)"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsNonvestedandVestedNumber",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "es_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsNonvestedandVestedWeightedAverageGrantDateFairValue": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested and Vested Weighted Average Grant Date Fair Value",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested and Vested Weighted Average Grant Date Fair Value",
        "periodEndLabel": "Ending balance (in dollars per share)",
        "periodStartLabel": "Beginning balance (in dollars per share)"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsNonvestedandVestedWeightedAverageGrantDateFairValue",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "es_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsSharesIssuedinPeriod": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Shares Issued in Period",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Shares Issued in Period",
        "negatedTerseLabel": "Shares issued (in shares)"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsSharesIssuedinPeriod",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "es_ShortTermDebtAuthorizationCalculationMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Short Term Debt Authorization Calculation [Member]",
        "label": "Short Term Debt Authorization Calculation [Member]",
        "terseLabel": "Short Term Debt Authorization Calculation"
       }
      }
     },
     "localname": "ShortTermDebtAuthorizationCalculationMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_Shorttermborrowinglimitapprovedbyregulatoryagency": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Short-term borrowing limit approved by regulatory agency",
        "label": "Short-term borrowing limit approved by regulatory agency",
        "terseLabel": "Short-term borrowing limit approved by regulatory agency"
       }
      }
     },
     "localname": "Shorttermborrowinglimitapprovedbyregulatoryagency",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_Shorttermdebtborrowingcalculationapprovedbyregulatoryagency": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "",
        "label": "Short-term debt borrowing calculation approved by regulatory agency",
        "terseLabel": "Short-term debt borrowing calculation approved by regulatory agency"
       }
      }
     },
     "localname": "Shorttermdebtborrowingcalculationapprovedbyregulatoryagency",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_SocialSecurityTaxEmployerDeferralCARESAct": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Social Security Tax, Employer, Deferral, CARES Act",
        "label": "Social Security Tax, Employer, Deferral, CARES Act",
        "terseLabel": "Tax liability related to the deferral of employer payroll tax liability provision of the CARES Act"
       }
      }
     },
     "localname": "SocialSecurityTaxEmployerDeferralCARESAct",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_SouthForkWindLLCMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "South Fork Wind LLC",
        "label": "South Fork Wind LLC [Member]",
        "terseLabel": "South Fork Wind, LLC"
       }
      }
     },
     "localname": "SouthForkWindLLCMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SpentNuclearFuelObilgationCyMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Spent Nuclear Fuel Obilgation CY [Member]",
        "terseLabel": "Pre-1983 Spent Nuclear Fuel Obligation (CYAPC)"
       }
      }
     },
     "localname": "SpentNuclearFuelObilgationCyMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_StormRestorationCostsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The storm cost deferrals relate to costs incurred by the regulated company for restorations that met regulatory agency specified criteria for deferral to a major storm cost reserve.",
        "label": "Storm Restoration Costs [Member]",
        "terseLabel": "Storm Costs, Net"
       }
      }
     },
     "localname": "StormRestorationCostsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SummaryofAccountingPoliciesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Line Items] for Summary of Accounting Policies [Table]",
        "label": "Summary of Accounting Policies [Line Items]",
        "terseLabel": "Summary of Accounting Policies [Line Items]"
       }
      }
     },
     "localname": "SummaryofAccountingPoliciesLineItems",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofOperatingExpensesDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofOtherTaxesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_SummaryofAccountingPoliciesTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Summary of Accounting Policies [Table]",
        "label": "Summary of Accounting Policies [Table]",
        "terseLabel": "Summary of Accounting Policies [Table]"
       }
      }
     },
     "localname": "SummaryofAccountingPoliciesTable",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofOperatingExpensesDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofOtherTaxesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_SunriseWindLLCMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sunrise Wind, LLC [Member]",
        "label": "Sunrise Wind, LLC [Member]",
        "terseLabel": "Sunrise Wind LLC"
       }
      }
     },
     "localname": "SunriseWindLLCMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SupplyAndStrandedCostObligationsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Supply And Stranded Cost Obligations [Member]",
        "terseLabel": "Purchased Power and Capacity"
       }
      }
     },
     "localname": "SupplyAndStrandedCostObligationsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_SupplyAndStrandedCostsObligationsIncurred": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Supply And Stranded Costs Obligations Incurred",
        "terseLabel": "Purchased Power and Capacity"
       }
      }
     },
     "localname": "SupplyAndStrandedCostsObligationsIncurred",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofTotalCostsIncurredDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_TangibleAssetImpairmentChargesAfterTax": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tangible Asset Impairment Charges, After Tax",
        "label": "Tangible Asset Impairment Charges, After Tax",
        "negatedTerseLabel": "After-tax impact of impairment charge"
       }
      }
     },
     "localname": "TangibleAssetImpairmentChargesAfterTax",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_TangibleAssetImpairmentChargesAfterTaxPerShare": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tangible Asset Impairment Charges, After Tax, Per Share",
        "label": "Tangible Asset Impairment Charges, After Tax, Per Share",
        "negatedTerseLabel": "After-tax impact of impairment charge (in dollars per share)"
       }
      }
     },
     "localname": "TangibleAssetImpairmentChargesAfterTaxPerShare",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "es_TaxCreditAndOperatingLossCarryforwardValuationAllowance": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of valuation allowance pertaining to the deferred tax asset representing potential future taxable deductions from tax credit carryforwards and operating loss carryforwards for which it is more likely than not that a tax benefit will not be realized.",
        "label": "Tax Credit and Operating Loss Carryforward Valuation Allowance",
        "terseLabel": "Valuation allowance for tax credit and operating loss carryforward"
       }
      }
     },
     "localname": "TaxCreditAndOperatingLossCarryforwardValuationAllowance",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_TaxRemittanceToStateForEnergyEfficiencyFunds": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tax Remittance To State For Energy Efficiency Funds",
        "label": "Tax Remittance To State For Energy Efficiency Funds",
        "terseLabel": "Tax remittance to state for energy efficiency funds"
       }
      }
     },
     "localname": "TaxRemittanceToStateForEnergyEfficiencyFunds",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_TheConnecticutLightAndPowerCompanyMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "The Connecticut Light And Power Company [Member]",
        "terseLabel": "The Connecticut Light and Power Company",
        "verboseLabel": "The Connecticut Light and Power Company"
       }
      }
     },
     "localname": "TheConnecticutLightAndPowerCompanyMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails",
      "http://www.eversource.com/role/AuditInformation",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofNumberofSitesandReservesDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofReconciliationofActivityinEnvironmentalReserveDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofTotalCostsIncurredDetails",
      "http://www.eversource.com/role/COMMONSHARESCommonSharesAuthorizedandIssuedDetails",
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETSParenthetical_1",
      "http://www.eversource.com/role/COVERPAGE",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSVariationsUsingSignificantunobservableInputsDetails",
      "http://www.eversource.com/role/DIVIDENDRESTRICTIONSDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofCompensationExpenseandIncomeTaxBenefitDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofDefinedContributionPlansDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofFundedStatusDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofOtherRetirementBenefitsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails",
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails",
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationofUnrecognizedTaxBenefitDetails",
      "http://www.eversource.com/role/INCOMETAXESTaxCreditsandLossCarryforwardsDetails",
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails",
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails",
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails",
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails",
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONNarrativeDetails",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAggregateCompositeDepreciationRatesDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/REVENUESNarrativeDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONNarrativeDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAFUDCandWeightedAverageAFUDCDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofOtherTaxesDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSupplementalCashFlowInformationDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTransferofEnergyEfficiencyLoansDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "domainItemType"
    },
    "es_TotalAssetsBefore401hMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total Assets Before 401 (h) [Member]",
        "label": "Total Assets Before 401 (h) [Member]",
        "terseLabel": "Total Assets Before 401"
       }
      }
     },
     "localname": "TotalAssetsBefore401hMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_TotalOtherLongTermDebtMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Total Other Long-Term Debt [Member]",
        "terseLabel": "Total Other Long-Term Debt"
       }
      }
     },
     "localname": "TotalOtherLongTermDebtMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_TotalRetailSalesRevenueMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total Retail Sales Revenue [Member]",
        "label": "Total Retail Sales Revenue [Member]",
        "terseLabel": "Total Retail Tariff Sales Revenues"
       }
      }
     },
     "localname": "TotalRetailSalesRevenueMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_TransitionServicesAgreementTSAMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Transition Services Agreement (TSA)",
        "label": "Transition Services Agreement (TSA) [Member]",
        "terseLabel": "TSA"
       }
      }
     },
     "localname": "TransitionServicesAgreementTSAMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_TransmissionAssetsAverageUsefulLife": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Transmission Assets Average Useful Life",
        "label": "Transmission Assets Average Useful Life",
        "terseLabel": "Transmission - Electric"
       }
      }
     },
     "localname": "TransmissionAssetsAverageUsefulLife",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_TransmissionInterconnectionGuaranteeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Transmission Interconnection Guarantee",
        "label": "Transmission Interconnection Guarantee [Member]",
        "terseLabel": "Transmission Interconnection"
       }
      }
     },
     "localname": "TransmissionInterconnectionGuaranteeMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_TransmissionSupportCommitmentCostsIncurred": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "label": "Transmission Support Commitment Costs Incurred",
        "terseLabel": "Transmission Support Commitments"
       }
      }
     },
     "localname": "TransmissionSupportCommitmentCostsIncurred",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofTotalCostsIncurredDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_TransmissionSupportCommitmentsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Transmission Support Commitments [Member]",
        "terseLabel": "Transmission Support Commitments"
       }
      }
     },
     "localname": "TransmissionSupportCommitmentsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_TropicalStormIsaiasMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tropical Storm Isaias",
        "label": "Tropical Storm Isaias [Member]",
        "terseLabel": "Tropical Storm Isaias"
       }
      }
     },
     "localname": "TropicalStormIsaiasMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_TypeOfInventoryByMajorAssetClassAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Type of inventory by major asset class",
        "label": "Type Of Inventory By Major Asset Class [Axis]",
        "terseLabel": "Type Of Inventory By Major Asset Class [Axis]"
       }
      }
     },
     "localname": "TypeOfInventoryByMajorAssetClassAxis",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "es_TypeOfInventoryByMajorAssetClassMemberDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Type of inventory by major asset class",
        "label": "Type Of Inventory By Major Asset Class Member [Domain]",
        "terseLabel": "Type Of Inventory By Major Asset Class Member [Domain]"
       }
      }
     },
     "localname": "TypeOfInventoryByMajorAssetClassMemberDomain",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_UIMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "UI [Member]",
        "label": "UI [Member]",
        "terseLabel": "UI"
       }
      }
     },
     "localname": "UIMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_UnrecordedUnconditionalPurchaseObligationAmountofCapacityContracts": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unrecorded Unconditional Purchase Obligation, Amount of Capacity Contracts",
        "label": "Unrecorded Unconditional Purchase Obligation, Amount of Capacity Contracts",
        "terseLabel": "Amount of peaking capacity contracts (in MW)"
       }
      }
     },
     "localname": "UnrecordedUnconditionalPurchaseObligationAmountofCapacityContracts",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "powerItemType"
    },
    "es_UnrecordedUnconditionalPurchaseObligationNumberofCapacityContracts": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unrecorded Unconditional Purchase Obligation, Number of Capacity Contracts",
        "label": "Unrecorded Unconditional Purchase Obligation, Number of Capacity Contracts",
        "terseLabel": "Number of capacity contracts"
       }
      }
     },
     "localname": "UnrecordedUnconditionalPurchaseObligationNumberofCapacityContracts",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "es_UnrecordedUnconditionalPurchaseObligationPeriodofPaymentofAnnualOperationandMaintenanceExpense": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unrecorded Unconditional Purchase Obligation, Period of Payment of Annual Operation and Maintenance Expense",
        "label": "Unrecorded Unconditional Purchase Obligation, Period of Payment of Annual Operation and Maintenance Expense",
        "terseLabel": "Period of payment of annual operation and maintenance expense"
       }
      }
     },
     "localname": "UnrecordedUnconditionalPurchaseObligationPeriodofPaymentofAnnualOperationandMaintenanceExpense",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_UnrecordedUnconditionalPurchaseObligationPeriodofPaymenttoGenerationFacilityOwner": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unrecorded Unconditional Purchase Obligation, Period of Payment to Generation Facility Owner",
        "label": "Unrecorded Unconditional Purchase Obligation, Period of Payment to Generation Facility Owner",
        "terseLabel": "Period of payment to generation facility owner"
       }
      }
     },
     "localname": "UnrecordedUnconditionalPurchaseObligationPeriodofPaymenttoGenerationFacilityOwner",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_UnsecuredNotesDue20222051Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unsecured Notes Due 2018-2044 [Member]",
        "label": "Unsecured Notes Due 2022-2051 [Member]",
        "terseLabel": "Yankee Gas - First Mortgage Bonds: 1.380% - 8.480% due 2022 - 2051"
       }
      }
     },
     "localname": "UnsecuredNotesDue20222051Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_UnsecuredNotesDue2022Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unsecured Notes Due 2022 [Member]",
        "label": "Unsecured Notes Due 2022 [Member]",
        "terseLabel": "2.375% due 2022"
       }
      }
     },
     "localname": "UnsecuredNotesDue2022Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_UnsecuredNotesDue20232051Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unsecured Notes Due 2021-2037 [Member]",
        "label": "Unsecured Notes Due 2023-2051 [Member]",
        "terseLabel": "Aquarion - Unsecured Notes 0% - 6.430% due 2023 - 2051"
       }
      }
     },
     "localname": "UnsecuredNotesDue20232051Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_UnsecuredNotesDue20252051Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unsecured Notes Due 2025-2051 [Member]",
        "label": "Unsecured Notes Due 2025-2051 [Member]",
        "terseLabel": "NSTAR Gas - First Mortgage Bonds: 2.250% - 7.110% due 2025 - 2051"
       }
      }
     },
     "localname": "UnsecuredNotesDue20252051Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_UnsecuredNotesDue2025Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unsecured Notes Due 2025 [Member]",
        "label": "Unsecured Notes Due 2025 [Member]",
        "terseLabel": "3.250% due 2025"
       }
      }
     },
     "localname": "UnsecuredNotesDue2025Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_UnsecuredNotesDue2026Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unsecured Notes Due 2026 [Member]",
        "label": "Unsecured Notes Due 2026 [Member]",
        "terseLabel": "2.700% due 2026"
       }
      }
     },
     "localname": "UnsecuredNotesDue2026Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_UnsecuredNotesDue2027Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unsecured Notes Due 2027 [Member]",
        "label": "Unsecured Notes Due 2027 [Member]",
        "terseLabel": "3.200% due 2027"
       }
      }
     },
     "localname": "UnsecuredNotesDue2027Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_UnsecuredNotesDue2029Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unsecured Notes Due 2029 [Member]",
        "label": "Unsecured Notes Due 2029 [Member]",
        "terseLabel": "3.250% due 2029"
       }
      }
     },
     "localname": "UnsecuredNotesDue2029Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_UnsecuredNotesDue20312051Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unsecured Notes Due 2031-2051",
        "label": "Unsecured Notes Due 2031-2051 [Member]",
        "terseLabel": "EGMA - First Mortgage Bonds: 2.110% - 2.920% due 2031 - 2051"
       }
      }
     },
     "localname": "UnsecuredNotesDue20312051Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_UnsecuredNotesDue2036Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unsecured Notes Due 2036 [Member]",
        "label": "Unsecured Notes Due 2036 [Member]",
        "terseLabel": "5.750% due 2036"
       }
      }
     },
     "localname": "UnsecuredNotesDue2036Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_UnsecuredNotesDue2040Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unsecured Notes Due 2040 [Member]",
        "label": "Unsecured Notes Due 2040 [Member]",
        "terseLabel": "5.500% due 2040"
       }
      }
     },
     "localname": "UnsecuredNotesDue2040Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_UnsecuredNotesDue2044Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unsecured Notes Due 2044 [Member]",
        "label": "Unsecured Notes Due 2044 [Member]",
        "terseLabel": "4.400% due 2044"
       }
      }
     },
     "localname": "UnsecuredNotesDue2044Member",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_UtilitiesOperatingExpensePurchasedPowerPurchasedTransmissionAndFuelUsed": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 1.0,
       "parentTag": "us-gaap_OperatingExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Utilities Operating Expense, Purchased Power, Purchased Transmission, And Fuel Used",
        "label": "Utilities Operating Expense, Purchased Power, Purchased Transmission, And Fuel Used",
        "terseLabel": "Purchased Power and Transmission"
       }
      }
     },
     "localname": "UtilitiesOperatingExpensePurchasedPowerPurchasedTransmissionAndFuelUsed",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "es_VariousEntitiesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Various Entities",
        "label": "Various Entities [Member]",
        "terseLabel": "Various"
       }
      }
     },
     "localname": "VariousEntitiesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_WaterAssetsAverageUsefulLife": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Water Assets Average Useful Life",
        "label": "Water Assets Average Useful Life",
        "terseLabel": "Distribution - Water"
       }
      }
     },
     "localname": "WaterAssetsAverageUsefulLife",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "es_WaterDistributionSegmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Water Distribution Segment",
        "label": "Water Distribution Segment [Member]",
        "terseLabel": "Water Distribution"
       }
      }
     },
     "localname": "WaterDistributionSegmentMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/GOODWILLNarrativeDetails",
      "http://www.eversource.com/role/GOODWILLSummaryofGoodwillbyReportableSegmentDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_WholesaleMarketSalesRevenueMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Wholesale Market Sales Revenue [Member]",
        "label": "Wholesale Market Sales Revenue [Member]",
        "terseLabel": "Wholesale Market Sales Revenues"
       }
      }
     },
     "localname": "WholesaleMarketSalesRevenueMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_WholesaleTransmissionRevenueMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Wholesale Transmission Revenue [Member]",
        "label": "Wholesale Transmission Revenue [Member]",
        "terseLabel": "Wholesale Transmission Revenues"
       }
      }
     },
     "localname": "WholesaleTransmissionRevenueMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_YAECMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "YAEC [Member]",
        "label": "YAEC [Member]",
        "terseLabel": "YAEC"
       }
      }
     },
     "localname": "YAECMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_YankeeCompaniesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Yankee Companies [Member]",
        "terseLabel": "Yankee Companies"
       }
      }
     },
     "localname": "YankeeCompaniesMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_YankeeGas288SeriesTFirstMortgageBondsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Yankee Gas 2.88% Series T First Mortgage Bonds",
        "label": "Yankee Gas 2.88% Series T First Mortgage Bonds [Member]",
        "terseLabel": "Yankee Gas 2.88% Series T First Mortgage Bonds"
       }
      }
     },
     "localname": "YankeeGas288SeriesTFirstMortgageBondsMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_YankeeGasMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Yankee Gas",
        "label": "Yankee Gas [Member]",
        "terseLabel": "Yankee Gas"
       }
      }
     },
     "localname": "YankeeGasMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_YankeeGasNSTARGasAndEGMAMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Yankee Gas, NSTAR Gas And EGMA",
        "label": "Yankee Gas, NSTAR Gas And EGMA [Member]",
        "terseLabel": "Yankee Gas, NSTAR Gas and EGMA"
       }
      }
     },
     "localname": "YankeeGasNSTARGasAndEGMAMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SEGMENTINFORMATIONNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "es_YankeeGasServicesCompanyMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Yankee Gas Services Company [Member]",
        "terseLabel": "Yankee Gas Services Company"
       }
      }
     },
     "localname": "YankeeGasServicesCompanyMember",
     "nsuri": "http://www.eversource.com/20211231",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_CondensedBalanceSheetStatementTable": {
     "auth_ref": [
      "r175",
      "r699",
      "r983"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about condensed balance sheet, including, but not limited to, balance sheets of consolidated entities and consolidation eliminations.",
        "label": "Condensed Balance Sheet Statement [Table]",
        "terseLabel": "Condensed Balance Sheet Statement [Table]"
       }
      }
     },
     "localname": "CondensedBalanceSheetStatementTable",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_CondensedBalanceSheetStatementsCaptionsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Condensed Balance Sheet Statements, Captions [Line Items]",
        "terseLabel": "Condensed Balance Sheet Statements, Captions [Line Items]"
       }
      }
     },
     "localname": "CondensedBalanceSheetStatementsCaptionsLineItems",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_CondensedCashFlowStatementTable": {
     "auth_ref": [
      "r175",
      "r699",
      "r992"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about condensed cash flow statement, including, but not limited to, cash flow statements of consolidated entities and consolidation eliminations.",
        "label": "Condensed Cash Flow Statement [Table]",
        "terseLabel": "Condensed Cash Flow Statement [Table]"
       }
      }
     },
     "localname": "CondensedCashFlowStatementTable",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_CondensedCashFlowStatementsCaptionsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Condensed Cash Flow Statements, Captions [Line Items]",
        "terseLabel": "Condensed Cash Flow Statements, Captions [Line Items]"
       }
      }
     },
     "localname": "CondensedCashFlowStatementsCaptionsLineItems",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_CondensedFinancialInformationOfParentCompanyOnlyDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Condensed Financial Information Disclosure [Abstract]",
        "terseLabel": "Condensed Financial Information Disclosure [Abstract]"
       }
      }
     },
     "localname": "CondensedFinancialInformationOfParentCompanyOnlyDisclosureAbstract",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "srt_CondensedIncomeStatementTable": {
     "auth_ref": [
      "r175",
      "r699",
      "r992"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about condensed income statement including, but not limited to, income statements of consolidated entities and consolidation eliminations.",
        "label": "Condensed Income Statement [Table]",
        "terseLabel": "Condensed Income Statement [Table]"
       }
      }
     },
     "localname": "CondensedIncomeStatementTable",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESIncomeStatementDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_CondensedIncomeStatementsCaptionsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Condensed Income Statements, Captions [Line Items]",
        "terseLabel": "Condensed Income Statements, Captions [Line Items]"
       }
      }
     },
     "localname": "CondensedIncomeStatementsCaptionsLineItems",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESIncomeStatementDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_CondensedStatementOfComprehensiveIncomeTable": {
     "auth_ref": [
      "r175",
      "r699",
      "r983"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about condensed statement of comprehensive income (loss) including, but not limited to, statements of comprehensive income (loss) of consolidated entities and consolidation eliminations.",
        "label": "Condensed Statement of Comprehensive Income [Table]",
        "terseLabel": "Condensed Statement of Comprehensive Income [Table]"
       }
      }
     },
     "localname": "CondensedStatementOfComprehensiveIncomeTable",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFCOMPREHENSIVEINCOMEDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_CondensedStatementOfIncomeCaptionsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Condensed Statement of Income Captions [Line Items]",
        "terseLabel": "Condensed Statement of Income Captions [Line Items]"
       }
      }
     },
     "localname": "CondensedStatementOfIncomeCaptionsLineItems",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFCOMPREHENSIVEINCOMEDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ConsolidatedEntitiesAxis": {
     "auth_ref": [
      "r175",
      "r414",
      "r419",
      "r427",
      "r703",
      "r704",
      "r710",
      "r711",
      "r823",
      "r946",
      "r981",
      "r994",
      "r1003",
      "r1004"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by consolidated entity or group of entities.",
        "label": "Consolidated Entities [Axis]",
        "terseLabel": "Consolidated Entities [Axis]"
       }
      }
     },
     "localname": "ConsolidatedEntitiesAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESIncomeStatementDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFCOMPREHENSIVEINCOMEDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTScheduleofDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ConsolidatedEntitiesDomain": {
     "auth_ref": [
      "r175",
      "r414",
      "r419",
      "r427",
      "r703",
      "r704",
      "r710",
      "r711",
      "r823",
      "r946",
      "r981",
      "r994",
      "r1003",
      "r1004"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Entity or group of entities consolidated into reporting entity.",
        "label": "Consolidated Entities [Domain]",
        "terseLabel": "Consolidated Entities [Domain]"
       }
      }
     },
     "localname": "ConsolidatedEntitiesDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESIncomeStatementDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFCOMPREHENSIVEINCOMEDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTScheduleofDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ConsolidationEliminationsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Eliminating entries used in consolidating a parent entity and its subsidiaries.",
        "label": "Consolidation, Eliminations [Member]",
        "terseLabel": "Consolidations Eliminations"
       }
      }
     },
     "localname": "ConsolidationEliminationsMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ConsolidationItemsAxis": {
     "auth_ref": [
      "r175",
      "r234",
      "r247",
      "r248",
      "r249",
      "r250",
      "r252",
      "r254",
      "r258",
      "r414",
      "r415",
      "r416",
      "r417",
      "r418",
      "r419",
      "r421",
      "r422",
      "r424",
      "r426",
      "r427",
      "r994",
      "r995",
      "r996",
      "r997",
      "r998",
      "r999",
      "r1000",
      "r1001",
      "r1002",
      "r1003",
      "r1004"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by components, eliminations, non-segment corporate-level activity and reconciling items used in consolidating a parent entity and its subsidiaries or its operating segments.",
        "label": "Consolidation Items [Axis]",
        "terseLabel": "Consolidation Items [Axis]"
       }
      }
     },
     "localname": "ConsolidationItemsAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESNarrativeDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ConsolidationItemsDomain": {
     "auth_ref": [
      "r175",
      "r234",
      "r247",
      "r248",
      "r249",
      "r250",
      "r252",
      "r254",
      "r258",
      "r414",
      "r415",
      "r416",
      "r417",
      "r418",
      "r419",
      "r421",
      "r422",
      "r424",
      "r426",
      "r427",
      "r994",
      "r995",
      "r996",
      "r997",
      "r998",
      "r999",
      "r1000",
      "r1001",
      "r1002",
      "r1003",
      "r1004"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Components, elimination, non-segment corporate-level activity and reconciling items used in consolidating a parent entity and its subsidiaries or its operating segments.",
        "label": "Consolidation Items [Domain]",
        "terseLabel": "Consolidation Items [Domain]"
       }
      }
     },
     "localname": "ConsolidationItemsDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESNarrativeDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_CounterpartyNameAxis": {
     "auth_ref": [
      "r77",
      "r80",
      "r172",
      "r173",
      "r433",
      "r466",
      "r1005"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by name of counterparty. A counterparty is the other party that participates in a financial transaction. Examples include, but not limited to, the name of the financial institution.",
        "label": "Counterparty Name [Axis]",
        "terseLabel": "Counterparty Name [Axis]"
       }
      }
     },
     "localname": "CounterpartyNameAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember": {
     "auth_ref": [
      "r2",
      "r189",
      "r197",
      "r204",
      "r314",
      "r628",
      "r629",
      "r630",
      "r666",
      "r667",
      "r745",
      "r748",
      "r750",
      "r751",
      "r1009"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Increase (decrease) to financial statements for cumulative-effect adjustment in period of adoption of amendment to accounting standards.",
        "label": "Cumulative Effect, Period of Adoption, Adjustment [Member]",
        "terseLabel": "Adoption of New Accounting Standard"
       }
      }
     },
     "localname": "CumulativeEffectPeriodOfAdoptionAdjustmentMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_CumulativeEffectPeriodOfAdoptionAxis": {
     "auth_ref": [
      "r2",
      "r189",
      "r197",
      "r204",
      "r314",
      "r628",
      "r629",
      "r630",
      "r666",
      "r667",
      "r745",
      "r748",
      "r750",
      "r751",
      "r1009"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by cumulative-effect adjustment to financial statements in period of adoption of amendment to accounting standards.",
        "label": "Cumulative Effect, Period of Adoption [Axis]",
        "terseLabel": "Cumulative Effect, Period of Adoption [Axis]"
       }
      }
     },
     "localname": "CumulativeEffectPeriodOfAdoptionAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_CumulativeEffectPeriodOfAdoptionDomain": {
     "auth_ref": [
      "r2",
      "r189",
      "r197",
      "r204",
      "r314",
      "r628",
      "r629",
      "r630",
      "r666",
      "r667",
      "r745",
      "r748",
      "r750",
      "r751",
      "r1009"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cumulative-effect adjustment to financial statements in period of adoption of amendment to accounting standards.",
        "label": "Cumulative Effect, Period of Adoption [Domain]",
        "terseLabel": "Cumulative Effect, Period of Adoption [Domain]"
       }
      }
     },
     "localname": "CumulativeEffectPeriodOfAdoptionDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_EquityMethodInvesteeNameDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of investment including named security. Excludes entity that is consolidated.",
        "label": "Investment, Name [Domain]",
        "terseLabel": "Investment, Name [Domain]"
       }
      }
     },
     "localname": "EquityMethodInvesteeNameDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails",
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails",
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESSummaryofInvestmentsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_LitigationCaseAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of judicial proceeding, alternative dispute resolution or claim.",
        "label": "Litigation Case [Axis]",
        "terseLabel": "Litigation Case [Axis]"
       }
      }
     },
     "localname": "LitigationCaseAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_LitigationCaseTypeDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Judicial proceeding, alternative dispute resolution or claim. For example, but not limited to, name of case, category of litigation, or other differentiating information.",
        "label": "Litigation Case [Domain]",
        "terseLabel": "Litigation Case [Domain]"
       }
      }
     },
     "localname": "LitigationCaseTypeDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_MaximumMember": {
     "auth_ref": [
      "r432",
      "r465",
      "r598",
      "r608",
      "r835",
      "r836",
      "r837",
      "r838",
      "r839",
      "r840",
      "r860",
      "r912",
      "r915",
      "r947",
      "r948"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Upper limit of the provided range.",
        "label": "Maximum [Member]",
        "terseLabel": "Maximum"
       }
      }
     },
     "localname": "MaximumMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssumptionsusedToCalculatePensionandSERPandPBOPDetails",
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_MinimumMember": {
     "auth_ref": [
      "r432",
      "r465",
      "r598",
      "r608",
      "r835",
      "r836",
      "r837",
      "r838",
      "r839",
      "r840",
      "r860",
      "r912",
      "r915",
      "r947",
      "r948"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Lower limit of the provided range.",
        "label": "Minimum [Member]",
        "terseLabel": "Minimum"
       }
      }
     },
     "localname": "MinimumMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssumptionsusedToCalculatePensionandSERPandPBOPDetails",
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ParentCompanyMember": {
     "auth_ref": [
      "r175"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The registrant that controls, directly or indirectly, another entity (or entities). The usual condition for control is ownership of a majority (over 50%) of the outstanding voting stock. The power to control may also exist with a lesser percentage of ownership, for example, by contract, lease, agreement with other stockholders or by court decree.",
        "label": "Parent Company [Member]",
        "terseLabel": "Eversource",
        "verboseLabel": "Eversource Parent Commercial Paper Program"
       }
      }
     },
     "localname": "ParentCompanyMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFCOMPREHENSIVEINCOMEDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTScheduleofDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ProductOrServiceAxis": {
     "auth_ref": [
      "r261",
      "r500",
      "r502",
      "r862",
      "r911",
      "r913"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by product and service, or group of similar products and similar services.",
        "label": "Product and Service [Axis]",
        "terseLabel": "Product and Service [Axis]"
       }
      }
     },
     "localname": "ProductOrServiceAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESNarrativeDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ProductsAndServicesDomain": {
     "auth_ref": [
      "r261",
      "r500",
      "r502",
      "r862",
      "r911",
      "r913"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Product or service, or a group of similar products or similar services.",
        "label": "Product and Service [Domain]",
        "terseLabel": "Product and Service [Domain]"
       }
      }
     },
     "localname": "ProductsAndServicesDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESNarrativeDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RangeAxis": {
     "auth_ref": [
      "r432",
      "r465",
      "r541",
      "r598",
      "r608",
      "r835",
      "r836",
      "r837",
      "r838",
      "r839",
      "r840",
      "r860",
      "r912",
      "r915",
      "r947",
      "r948"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by statistical measurement. Includes, but is not limited to, minimum, maximum, weighted average, arithmetic average, and median.",
        "label": "Statistical Measurement [Axis]",
        "terseLabel": "Statistical Measurement [Axis]"
       }
      }
     },
     "localname": "RangeAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssumptionsusedToCalculatePensionandSERPandPBOPDetails",
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_RangeMember": {
     "auth_ref": [
      "r432",
      "r465",
      "r541",
      "r598",
      "r608",
      "r835",
      "r836",
      "r837",
      "r838",
      "r839",
      "r840",
      "r860",
      "r912",
      "r915",
      "r947",
      "r948"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Statistical measurement. Includes, but is not limited to, minimum, maximum, weighted average, arithmetic average, and median.",
        "label": "Statistical Measurement [Domain]",
        "terseLabel": "Statistical Measurement [Domain]"
       }
      }
     },
     "localname": "RangeMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssumptionsusedToCalculatePensionandSERPandPBOPDetails",
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RepurchaseAgreementCounterpartyNameDomain": {
     "auth_ref": [
      "r79",
      "r80",
      "r172",
      "r173",
      "r433",
      "r466"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Named other party that participates in a financial transaction. Examples include, but not limited to, the name of the financial institution.",
        "label": "Counterparty Name [Domain]",
        "terseLabel": "Counterparty Name [Domain]"
       }
      }
     },
     "localname": "RepurchaseAgreementCounterpartyNameDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RestatementAdjustmentMember": {
     "auth_ref": [
      "r186",
      "r187",
      "r188",
      "r190",
      "r191",
      "r194",
      "r195",
      "r197",
      "r199",
      "r200",
      "r202",
      "r203",
      "r220",
      "r750",
      "r751"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cumulative increase (decrease) for adjustment to previously issued financial statements. Includes, but is not limited to, adjustment for retrospective application of amendment to accounting standards, other change in accounting principle, correction of error, and other revision.",
        "label": "Revision of Prior Period, Adjustment [Member]",
        "terseLabel": "Restatement Adjustment"
       }
      }
     },
     "localname": "RestatementAdjustmentMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RestatementAxis": {
     "auth_ref": [
      "r3",
      "r186",
      "r187",
      "r188",
      "r190",
      "r191",
      "r194",
      "r195",
      "r196",
      "r197",
      "r199",
      "r200",
      "r201",
      "r202",
      "r203",
      "r204",
      "r220",
      "r315",
      "r316",
      "r631",
      "r667",
      "r746",
      "r750",
      "r751",
      "r752",
      "r918",
      "r919",
      "r920",
      "r921",
      "r922",
      "r923",
      "r924",
      "r925",
      "r926",
      "r927",
      "r1010",
      "r1011"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by adjustment to previously issued financial statements. Includes, but is not limited to, adjustment for retrospective application of amendment to accounting standards, other change in accounting principle, correction of error, and other revision.",
        "label": "Revision of Prior Period [Axis]",
        "terseLabel": "Restatement [Axis]"
       }
      }
     },
     "localname": "RestatementAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_RestatementDomain": {
     "auth_ref": [
      "r3",
      "r186",
      "r187",
      "r188",
      "r190",
      "r191",
      "r194",
      "r195",
      "r196",
      "r197",
      "r199",
      "r200",
      "r201",
      "r202",
      "r203",
      "r204",
      "r220",
      "r315",
      "r316",
      "r631",
      "r667",
      "r746",
      "r750",
      "r751",
      "r752",
      "r918",
      "r919",
      "r920",
      "r921",
      "r922",
      "r923",
      "r924",
      "r925",
      "r926",
      "r927",
      "r1010",
      "r1011"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Adjustment to previously issued financial statements. Includes, but is not limited to, adjustment for retrospective application of amendment to accounting standards, other change in accounting principle, correction of error, and other revision.",
        "label": "Revision of Prior Period [Domain]",
        "terseLabel": "Restatement [Domain]"
       }
      }
     },
     "localname": "RestatementDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis": {
     "auth_ref": [
      "r305"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by name of investment including named security. Excludes entity that is consolidated.",
        "label": "Investment, Name [Axis]",
        "terseLabel": "Investment, Name [Axis]"
       }
      }
     },
     "localname": "ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails",
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails",
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESSummaryofInvestmentsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock": {
     "auth_ref": [
      "r184",
      "r993"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for valuation and qualifying accounts and reserves.",
        "label": "SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]",
        "terseLabel": "SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES"
       }
      }
     },
     "localname": "ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVES"
     ],
     "xbrltype": "textBlockItemType"
    },
    "srt_SegmentGeographicalDomain": {
     "auth_ref": [
      "r262",
      "r263",
      "r500",
      "r503",
      "r914",
      "r937",
      "r938",
      "r939",
      "r940",
      "r941",
      "r942",
      "r943",
      "r944",
      "r945",
      "r980",
      "r984",
      "r985",
      "r986",
      "r987",
      "r988",
      "r989",
      "r990",
      "r991"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Geographical area.",
        "label": "Geographical [Domain]",
        "terseLabel": "Geographical [Domain]"
       }
      }
     },
     "localname": "SegmentGeographicalDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_StatementGeographicalAxis": {
     "auth_ref": [
      "r262",
      "r263",
      "r500",
      "r503",
      "r914",
      "r932",
      "r937",
      "r938",
      "r939",
      "r940",
      "r941",
      "r942",
      "r943",
      "r944",
      "r945",
      "r980",
      "r982"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by geographical components.",
        "label": "Geographical [Axis]",
        "terseLabel": "Geographical [Axis]"
       }
      }
     },
     "localname": "StatementGeographicalAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_TitleOfIndividualAxis": {
     "auth_ref": [
      "r267",
      "r821"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by title of individual or nature of relationship to individual or group of individuals.",
        "label": "Title of Individual [Axis]",
        "terseLabel": "Title of Individual [Axis]"
       }
      }
     },
     "localname": "TitleOfIndividualAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_TitleOfIndividualWithRelationshipToEntityDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Title of individual, or nature of relationship to individual or group of individuals.",
        "label": "Title of Individual [Domain]",
        "terseLabel": "Title of Individual [Domain]"
       }
      }
     },
     "localname": "TitleOfIndividualWithRelationshipToEntityDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ValuationAndQualifyingAccountsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]",
        "terseLabel": "SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]"
       }
      }
     },
     "localname": "ValuationAndQualifyingAccountsAbstract",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "srt_ValuationAndQualifyingAccountsDisclosureLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]",
        "terseLabel": "SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]"
       }
      }
     },
     "localname": "ValuationAndQualifyingAccountsDisclosureLineItems",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ValuationAndQualifyingAccountsDisclosureTable": {
     "auth_ref": [
      "r177",
      "r178",
      "r179",
      "r182",
      "r183",
      "r993"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of valuation and qualifying accounts and reserves.",
        "label": "SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table]",
        "terseLabel": "SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table]"
       }
      }
     },
     "localname": "ValuationAndQualifyingAccountsDisclosureTable",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_WeightedAverageMember": {
     "auth_ref": [
      "r835",
      "r837",
      "r840",
      "r947",
      "r948"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Average of a range of values, calculated with consideration of proportional relevance.",
        "label": "Weighted Average [Member]",
        "terseLabel": "Weighted Average"
       }
      }
     },
     "localname": "WeightedAverageMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountingPoliciesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Accounting Policies [Abstract]",
        "terseLabel": "Accounting Policies [Abstract]"
       }
      }
     },
     "localname": "AccountingPoliciesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccountingStandardsUpdateExtensibleList": {
     "auth_ref": [
      "r0",
      "r1",
      "r2",
      "r3",
      "r4",
      "r190",
      "r191",
      "r192",
      "r193",
      "r276",
      "r277",
      "r311",
      "r312",
      "r313",
      "r314",
      "r315",
      "r316",
      "r413",
      "r624",
      "r625",
      "r626",
      "r627",
      "r628",
      "r629",
      "r630",
      "r631",
      "r666",
      "r667",
      "r742",
      "r743",
      "r744",
      "r745",
      "r746",
      "r747",
      "r748",
      "r749",
      "r750",
      "r751",
      "r752",
      "r773",
      "r774",
      "r775",
      "r776",
      "r777",
      "r778",
      "r779",
      "r780",
      "r818",
      "r916",
      "r917",
      "r918",
      "r919",
      "r920",
      "r921",
      "r922",
      "r923",
      "r924",
      "r925",
      "r926",
      "r927",
      "r1007",
      "r1008",
      "r1009",
      "r1010",
      "r1011"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates amendment to accounting standards.",
        "label": "Accounting Standards Update [Extensible Enumeration]",
        "terseLabel": "Accounting Standards Update [Extensible Enumeration]"
       }
      }
     },
     "localname": "AccountingStandardsUpdateExtensibleList",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "enumerationSetItemType"
    },
    "us-gaap_AccountsNotesAndLoansReceivableLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Accounts, Notes, Loans and Financing Receivable [Line Items]",
        "terseLabel": "Accounts, Notes, Loans and Financing Receivable [Line Items]"
       }
      }
     },
     "localname": "AccountsNotesAndLoansReceivableLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTransferofEnergyEfficiencyLoansDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis": {
     "auth_ref": [
      "r66"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of receivable.",
        "label": "Receivable Type [Axis]",
        "terseLabel": "Receivable Type [Axis]"
       }
      }
     },
     "localname": "AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccountsPayableCurrent": {
     "auth_ref": [
      "r50",
      "r826"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 4.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
        "label": "Accounts Payable, Current",
        "terseLabel": "Accounts Payable"
       }
      }
     },
     "localname": "AccountsPayableCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccountsPayableOtherCurrent": {
     "auth_ref": [
      "r21",
      "r50"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 9.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of obligations incurred classified as other, payable within one year or the normal operating cycle, if longer.",
        "label": "Accounts Payable, Other, Current",
        "terseLabel": "Obligations to Third Party Suppliers"
       }
      }
     },
     "localname": "AccountsPayableOtherCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccountsPayableRelatedPartiesCurrent": {
     "auth_ref": [
      "r50",
      "r171",
      "r820",
      "r822"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 8.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
        "label": "Accounts Payable, Related Parties, Current",
        "terseLabel": "Accounts Payable to Affiliated Companies",
        "verboseLabel": "Accounts Payable to Subsidiaries"
       }
      }
     },
     "localname": "AccountsPayableRelatedPartiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccountsReceivableNetCurrent": {
     "auth_ref": [
      "r13",
      "r35",
      "r268",
      "r269"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 2.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.",
        "label": "Accounts Receivable, after Allowance for Credit Loss, Current",
        "terseLabel": "Receivables, Net (net of allowance for uncollectible accounts of $181,319 and $157,447 as of December 31, 2021 and 2020, respectively)"
       }
      }
     },
     "localname": "AccountsReceivableNetCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccountsReceivableRelatedPartiesCurrent": {
     "auth_ref": [
      "r64",
      "r171",
      "r819",
      "r822"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 7.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of receivables arising from transactions with related parties due within one year or the normal operating cycle, if longer.",
        "label": "Accounts Receivable, Related Parties, Current",
        "terseLabel": "Accounts Receivable from Affiliated Companies",
        "verboseLabel": "Accounts Receivable from Subsidiaries"
       }
      }
     },
     "localname": "AccountsReceivableRelatedPartiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccrualForEnvironmentalLossContingencies": {
     "auth_ref": [
      "r374",
      "r383",
      "r384"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total costs accrued as of the balance sheet date for environmental loss contingencies.",
        "label": "Accrual for Environmental Loss Contingencies",
        "periodEndLabel": "Accrual for Environmental Loss Contingencies, Ending Balance",
        "periodStartLabel": "Accrual for Environmental Loss Contingencies, Beginning Balance",
        "terseLabel": "Reserve"
       }
      }
     },
     "localname": "AccrualForEnvironmentalLossContingencies",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofReconciliationofActivityinEnvironmentalReserveDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses": {
     "auth_ref": [
      "r396"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of expense for newly incurred environmental loss contingencies. Includes, but is not limited to, remediation expense and interest accretion.",
        "label": "Accrual for Environmental Loss Contingencies, Charges to Expense for New Losses",
        "terseLabel": "Additions"
       }
      }
     },
     "localname": "AccrualForEnvironmentalLossContingenciesChargesToExpenseForNewLosses",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofReconciliationofActivityinEnvironmentalReserveDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccrualForEnvironmentalLossContingenciesComponentAmount": {
     "auth_ref": [
      "r396"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Recorded amount of the accrual for a material component of an environmental loss contingency.",
        "label": "Accrual for Environmental Loss Contingencies, Component Amount",
        "terseLabel": "Reserve balances related to former MGP sites"
       }
      }
     },
     "localname": "AccrualForEnvironmentalLossContingenciesComponentAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForAcquisitionsAndDivestitures": {
     "auth_ref": [
      "r396"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in the obligation for environmental loss contingencies from business acquisitions (divestitures).",
        "label": "Accrual for Environmental Loss Contingencies, Increase (Decrease) for Acquisitions and Divestitures",
        "negatedTerseLabel": "Increase Due to CMA Asset Acquisition"
       }
      }
     },
     "localname": "AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForAcquisitionsAndDivestitures",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofReconciliationofActivityinEnvironmentalReserveDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccrualForEnvironmentalLossContingenciesPayments1": {
     "auth_ref": [
      "r142",
      "r395"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow to settle environmental loss contingencies.",
        "label": "Accrual for Environmental Loss Contingencies, Payments",
        "negatedTerseLabel": "Payments/Reductions"
       }
      }
     },
     "localname": "AccrualForEnvironmentalLossContingenciesPayments1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofReconciliationofActivityinEnvironmentalReserveDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccrualForEnvironmentalLossContingenciesRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Accrual for Environmental Loss Contingencies [Roll Forward]",
        "terseLabel": "Accrual for Environmental Loss Contingencies [Roll Forward]"
       }
      }
     },
     "localname": "AccrualForEnvironmentalLossContingenciesRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofReconciliationofActivityinEnvironmentalReserveDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember": {
     "auth_ref": [
      "r90",
      "r97",
      "r107",
      "r108",
      "r109",
      "r709"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accumulated other comprehensive (income) loss related to defined benefit plans attributable to the parent.",
        "label": "Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]",
        "terseLabel": "Defined Benefit Plans"
       }
      }
     },
     "localname": "AccumulatedDefinedBenefitPlansAdjustmentMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails",
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember": {
     "auth_ref": [
      "r92",
      "r97",
      "r107",
      "r108",
      "r109",
      "r709"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accumulated other comprehensive (income) loss related to prior service cost (credit) component of defined benefit plans attributable to the parent.",
        "label": "Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member]",
        "terseLabel": "Amortization of Prior Service Credit/(Cost)"
       }
      }
     },
     "localname": "AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetUnamortizedGainLossMember": {
     "auth_ref": [
      "r89",
      "r97",
      "r107",
      "r108",
      "r109",
      "r709"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accumulated other comprehensive income (loss) related to gain (loss) component of defined benefit plans attributable to the parent.",
        "label": "Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member]",
        "terseLabel": "Amortization of Actuarial Losses"
       }
      }
     },
     "localname": "AccumulatedDefinedBenefitPlansAdjustmentNetUnamortizedGainLossMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccumulatedNetGainLossFromCashFlowHedgesIncludingPortionAttributableToNoncontrollingInterestMember": {
     "auth_ref": [
      "r85",
      "r97",
      "r709"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accumulated other comprehensive income (loss) resulting from gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges, including the portion attributable to the noncontrolling interest.",
        "label": "Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member]",
        "terseLabel": "Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest"
       }
      }
     },
     "localname": "AccumulatedNetGainLossFromCashFlowHedgesIncludingPortionAttributableToNoncontrollingInterestMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember": {
     "auth_ref": [
      "r85",
      "r97",
      "r708"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accumulated other comprehensive income (loss) resulting from gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges, attributable to the parent.",
        "label": "Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]",
        "terseLabel": "Qualified Cash Flow Hedging Instruments",
        "verboseLabel": "Qualified Cash Flow Hedging Instruments, Net of Tax"
       }
      }
     },
     "localname": "AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails",
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember": {
     "auth_ref": [
      "r86",
      "r87",
      "r88",
      "r97",
      "r107",
      "r108",
      "r109"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accumulated unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), attributable to parent.",
        "label": "AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]",
        "terseLabel": "Unrealized Gains/(Losses) on Marketable Securities"
       }
      }
     },
     "localname": "AccumulatedNetUnrealizedInvestmentGainLossMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Accumulated Other Comprehensive Income (Loss) [Line Items]",
        "terseLabel": "Accumulated Other Comprehensive Income (Loss) [Line Items]"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeLossLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax": {
     "auth_ref": [
      "r39",
      "r94",
      "r96",
      "r97",
      "r898",
      "r923",
      "r927"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 4.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.",
        "label": "Accumulated Other Comprehensive Income (Loss), Net of Tax",
        "terseLabel": "Accumulated Other Comprehensive Income",
        "verboseLabel": "Accumulated Other Comprehensive Loss"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeLossNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeLossTable": {
     "auth_ref": [
      "r107",
      "r108",
      "r782",
      "r783",
      "r784",
      "r785",
      "r786",
      "r788"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about components of accumulated other comprehensive income (loss).",
        "label": "Accumulated Other Comprehensive Income (Loss) [Table]",
        "terseLabel": "Accumulated Other Comprehensive Income (Loss) [Table]"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeLossTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeMember": {
     "auth_ref": [
      "r93",
      "r97",
      "r107",
      "r108",
      "r109",
      "r186",
      "r187",
      "r188",
      "r709",
      "r918",
      "r919",
      "r1011"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accumulated increase (decrease) in equity from transactions and other events and circumstances from non-owner sources, attributable to the parent. Excludes net income (loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners.",
        "label": "AOCI Attributable to Parent [Member]",
        "terseLabel": "Total",
        "verboseLabel": "Accumulated Other Comprehensive Loss"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AdditionalCashFlowElementsInvestingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Additional Cash Flow Elements, Investing Activities [Abstract]",
        "terseLabel": "Non-Cash Investing Activities:"
       }
      }
     },
     "localname": "AdditionalCashFlowElementsInvestingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSupplementalCashFlowInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AdditionalPaidInCapital": {
     "auth_ref": [
      "r36",
      "r631",
      "r826"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 2.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of excess of issue price over par or stated value of stock and from other transaction involving stock or stockholder. Includes, but is not limited to, additional paid-in capital (APIC) for common and preferred stock.",
        "label": "Additional Paid in Capital",
        "terseLabel": "Capital Surplus, Paid In",
        "verboseLabel": "Capital Surplus, Paid in"
       }
      }
     },
     "localname": "AdditionalPaidInCapital",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AdditionalPaidInCapitalMember": {
     "auth_ref": [
      "r186",
      "r187",
      "r188",
      "r628",
      "r629",
      "r630",
      "r750"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders.",
        "label": "Additional Paid-in Capital [Member]",
        "terseLabel": "Capital Surplus, Paid In"
       }
      }
     },
     "localname": "AdditionalPaidInCapitalMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]",
        "terseLabel": "Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:"
       }
      }
     },
     "localname": "AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings": {
     "auth_ref": [
      "r479",
      "r487"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of decrease in additional paid in capital (APIC) resulting from dividends legally declared (or paid) in excess of retained earnings balance.",
        "label": "Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings",
        "negatedTerseLabel": "Dividends on Common Stock"
       }
      }
     },
     "localname": "AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts": {
     "auth_ref": [
      "r479",
      "r487"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of decrease in additional paid in capital (APIC) resulting from direct costs associated with issuing stock. Includes, but is not limited to, legal and accounting fees and direct costs associated with stock issues under a shelf registration.",
        "label": "Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs",
        "negatedTerseLabel": "Capital Stock Expense"
       }
      }
     },
     "localname": "AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]",
        "terseLabel": "Adjustments to Reconcile Net Income to Net Cash Flows Provided by Operating Activities:"
       }
      }
     },
     "localname": "AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AllocatedShareBasedCompensationExpense": {
     "auth_ref": [
      "r611",
      "r621",
      "r632"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.",
        "label": "Share-based Payment Arrangement, Expense",
        "terseLabel": "Compensation Expense"
       }
      }
     },
     "localname": "AllocatedShareBasedCompensationExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofCompensationExpenseandIncomeTaxBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AllowanceForCreditLossMember": {
     "auth_ref": [
      "r177",
      "r178",
      "r179",
      "r182",
      "r183"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Allowance for credit loss from right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.",
        "label": "SEC Schedule, 12-09, Allowance, Credit Loss [Member]",
        "terseLabel": "Allowance for Doubtful Accounts"
       }
      }
     },
     "localname": "AllowanceForCreditLossMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AllowanceForDoubtfulAccountsReceivable": {
     "auth_ref": [
      "r271",
      "r317",
      "r319",
      "r323"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of allowance for credit loss on accounts receivable.",
        "label": "Accounts Receivable, Allowance for Credit Loss",
        "periodEndLabel": "Balance as of December 31, 2020",
        "periodStartLabel": "Balance as of January 1, 2020",
        "terseLabel": "Allowance for uncollectible accounts for late fees and other receivable amounts",
        "verboseLabel": "Allowance for uncollectible accounts"
       }
      }
     },
     "localname": "AllowanceForDoubtfulAccountsReceivable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETSParenthetical",
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETSParenthetical_1",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETSParenthetical",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETSParenthetical",
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease": {
     "auth_ref": [
      "r324"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in allowance for credit loss on accounts receivable.",
        "label": "Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)",
        "terseLabel": "Accounts receivable, allowance for uncollectible accounts increase (decrease)"
       }
      }
     },
     "localname": "AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AllowanceForDoubtfulAccountsReceivableRecoveries": {
     "auth_ref": [
      "r322"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase in allowance for credit loss on accounts receivable, from recovery.",
        "label": "Accounts Receivable, Allowance for Credit Loss, Recovery",
        "terseLabel": "Recoveries Collected"
       }
      }
     },
     "localname": "AllowanceForDoubtfulAccountsReceivableRecoveries",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs": {
     "auth_ref": [
      "r321"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of direct write-downs of accounts receivable charged against the allowance.",
        "label": "Accounts Receivable, Allowance for Credit Loss, Writeoff",
        "negatedTerseLabel": "Write-Offs"
       }
      }
     },
     "localname": "AllowanceForDoubtfulAccountsReceivableWriteOffs",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AllowanceForFundsUsedDuringConstructionPolicy": {
     "auth_ref": [
      "r955"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy for AFUDC (for example, component of PPE, credit to income statement), information regarding the inclusion in rates (only capitalized if its inclusion in rates is probable) and description of AFUDC (for example, represents the cost of capital used during construction).",
        "label": "Allowance for Funds Used During Construction, Policy [Policy Text Block]",
        "terseLabel": "Allowance for Funds Used During Construction"
       }
      }
     },
     "localname": "AllowanceForFundsUsedDuringConstructionPolicy",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_AmortizationOfDeferredCharges": {
     "auth_ref": [
      "r123"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 8.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of amortization of deferred charges applied against earnings during the period.",
        "label": "Amortization of Deferred Charges",
        "terseLabel": "Amortization"
       }
      }
     },
     "localname": "AmortizationOfDeferredCharges",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AmortizationOfRegulatoryAsset": {
     "auth_ref": [
      "r123",
      "r152"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 18.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The expense charged against earnings during the period to allocate the capitalized costs of regulatory assets over the periods expected to benefit from such costs.",
        "label": "Amortization of Regulatory Asset",
        "terseLabel": "Amortization of Regulatory Assets, Net"
       }
      }
     },
     "localname": "AmortizationOfRegulatoryAsset",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESIncomeStatementDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AmountOfRegulatoryCostsNotYetApproved": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of regulatory costs not yet approved by the regulatory authority.",
        "label": "Amount of Regulatory Costs Not yet Approved",
        "terseLabel": "Amount of regulatory costs not yet approved"
       }
      }
     },
     "localname": "AmountOfRegulatoryCostsNotYetApproved",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount": {
     "auth_ref": [
      "r217"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.",
        "label": "Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount",
        "terseLabel": "Antidilutive share awards excluded from the EPS computation (in shares)"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EARNINGSPERSHARENarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_AssetBackedSecuritiesMember": {
     "auth_ref": [
      "r291",
      "r542"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Securities that are primarily serviced by the cash flows of a discrete pool of receivables or other financial assets for example, but not limited to, credit card receivables, car loans, recreational vehicle loans, and mobile home loans.",
        "label": "Asset-backed Securities [Member]",
        "terseLabel": "Asset-Backed Debt Securities"
       }
      }
     },
     "localname": "AssetBackedSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AssetRetirementObligation": {
     "auth_ref": [
      "r362"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.",
        "label": "Asset Retirement Obligation",
        "periodEndLabel": "Balance as of End of Year",
        "periodStartLabel": "Balance as of Beginning of Year",
        "terseLabel": "Asset retirement obligations"
       }
      }
     },
     "localname": "AssetRetirementObligation",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSNarrativeDetails",
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEversourceandNSTARElectricBostonHarborCivilActionDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetRetirementObligationAccretionExpense": {
     "auth_ref": [
      "r361",
      "r365"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.",
        "label": "Asset Retirement Obligation, Accretion Expense",
        "terseLabel": "Accretion"
       }
      }
     },
     "localname": "AssetRetirementObligationAccretionExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetRetirementObligationDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Asset Retirement Obligation Disclosure [Abstract]",
        "terseLabel": "Asset Retirement Obligation Disclosure [Abstract]"
       }
      }
     },
     "localname": "AssetRetirementObligationDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_AssetRetirementObligationDisclosureTextBlock": {
     "auth_ref": [
      "r367"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for an asset retirement obligation and the associated long-lived asset. An asset retirement obligation is a legal obligation associated with the disposal or retirement from service of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.",
        "label": "Asset Retirement Obligation Disclosure [Text Block]",
        "terseLabel": "ASSET RETIREMENT OBLIGATIONS"
       }
      }
     },
     "localname": "AssetRetirementObligationDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONS"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_AssetRetirementObligationLiabilitiesIncurred": {
     "auth_ref": [
      "r363"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of asset retirement obligations incurred during the period.",
        "label": "Asset Retirement Obligation, Liabilities Incurred",
        "terseLabel": "Liabilities Incurred During the Year"
       }
      }
     },
     "localname": "AssetRetirementObligationLiabilitiesIncurred",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetRetirementObligationLiabilitiesSettled": {
     "auth_ref": [
      "r364"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.",
        "label": "Asset Retirement Obligation, Liabilities Settled",
        "negatedTerseLabel": "Liabilities Settled During the Year"
       }
      }
     },
     "localname": "AssetRetirementObligationLiabilitiesSettled",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetRetirementObligationRevisionOfEstimate": {
     "auth_ref": [
      "r360",
      "r366"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in the asset retirement obligation from changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.",
        "label": "Asset Retirement Obligation, Revision of Estimate",
        "terseLabel": "Revisions in Estimated Cash Flows"
       }
      }
     },
     "localname": "AssetRetirementObligationRevisionOfEstimate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]",
        "terseLabel": "Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]"
       }
      }
     },
     "localname": "AssetRetirementObligationRollForwardAnalysisRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSScheduleofReconciliationofBeginningandEndingBalanceDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AssetRetirementObligationsNoncurrent": {
     "auth_ref": [
      "r362"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 4.0,
       "parentTag": "us-gaap_LiabilitiesOtherThanLongtermDebtNoncurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.",
        "label": "Asset Retirement Obligations, Noncurrent",
        "terseLabel": "Asset Retirement Obligations"
       }
      }
     },
     "localname": "AssetRetirementObligationsNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_Assets": {
     "auth_ref": [
      "r166",
      "r242",
      "r249",
      "r256",
      "r308",
      "r414",
      "r415",
      "r416",
      "r418",
      "r419",
      "r420",
      "r421",
      "r423",
      "r425",
      "r427",
      "r428",
      "r703",
      "r710",
      "r772",
      "r824",
      "r826",
      "r867",
      "r895"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.",
        "label": "Assets",
        "terseLabel": "Total Assets (as of)",
        "totalLabel": "Total Assets"
       }
      }
     },
     "localname": "Assets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Assets [Abstract]",
        "terseLabel": "ASSETS",
        "verboseLabel": "ASSETS"
       }
      }
     },
     "localname": "AssetsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AssetsCurrent": {
     "auth_ref": [
      "r16",
      "r18",
      "r72",
      "r166",
      "r308",
      "r414",
      "r415",
      "r416",
      "r418",
      "r419",
      "r420",
      "r421",
      "r423",
      "r425",
      "r427",
      "r428",
      "r703",
      "r710",
      "r772",
      "r824",
      "r826"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 1.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.",
        "label": "Assets, Current",
        "terseLabel": "Total Current Assets",
        "totalLabel": "Total Current Assets"
       }
      }
     },
     "localname": "AssetsCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetsCurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Assets, Current [Abstract]",
        "terseLabel": "Current Assets:",
        "verboseLabel": "Current Assets:"
       }
      }
     },
     "localname": "AssetsCurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AssetsNoncurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Assets, Noncurrent [Abstract]",
        "terseLabel": "Deferred Debits and Other Assets:"
       }
      }
     },
     "localname": "AssetsNoncurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 3.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      },
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sum of the carrying amounts as of the balance sheet date of all assets, excluding property, plant, and equipment and other property and investments, that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer. Alternate captions include Total Deferred Charges and Other Assets.",
        "label": "Assets, Noncurrent, Other than Noncurrent Investments and Property, Plant and Equipment",
        "totalLabel": "Total Deferred Debits and Other Assets"
       }
      }
     },
     "localname": "AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax": {
     "auth_ref": [
      "r282"
     ],
     "calculation": {
      "http://www.eversource.com/role/MARKETABLESECURITIESAvailableforSaleDebtSecuritiesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax",
        "terseLabel": "Pre-Tax Unrealized Gains"
       }
      }
     },
     "localname": "AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESAvailableforSaleDebtSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax": {
     "auth_ref": [
      "r283"
     ],
     "calculation": {
      "http://www.eversource.com/role/MARKETABLESECURITIESAvailableforSaleDebtSecuritiesDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax",
        "negatedTerseLabel": "Pre-Tax Unrealized Losses"
       }
      }
     },
     "localname": "AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESAvailableforSaleDebtSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis": {
     "auth_ref": [
      "r280",
      "r328"
     ],
     "calculation": {
      "http://www.eversource.com/role/MARKETABLESECURITIESAvailableforSaleDebtSecuritiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Available-for-sale, Amortized Cost",
        "totalLabel": "Amortized Cost"
       }
      }
     },
     "localname": "AvailableForSaleDebtSecuritiesAmortizedCostBasis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESAvailableforSaleDebtSecuritiesDetails",
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost": {
     "auth_ref": [
      "r288"
     ],
     "calculation": {
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10",
        "terseLabel": "Six to ten years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue": {
     "auth_ref": [
      "r284",
      "r288",
      "r889"
     ],
     "calculation": {
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesDebtSecurities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10",
        "terseLabel": "Six to ten years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost": {
     "auth_ref": [
      "r287"
     ],
     "calculation": {
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five",
        "terseLabel": "One to five years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue": {
     "auth_ref": [
      "r284",
      "r287",
      "r888"
     ],
     "calculation": {
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesDebtSecurities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five",
        "terseLabel": "One to five years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost": {
     "auth_ref": [
      "r289"
     ],
     "calculation": {
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing after tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10",
        "terseLabel": "Greater than ten years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue": {
     "auth_ref": [
      "r284",
      "r289",
      "r890"
     ],
     "calculation": {
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesDebtSecurities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing after tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10",
        "terseLabel": "Greater than ten years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value [Abstract]",
        "terseLabel": "Fair Value"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasisAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]",
        "terseLabel": "Amortized Cost"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasisAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost": {
     "auth_ref": [
      "r286"
     ],
     "calculation": {
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One",
        "terseLabel": "Less than one year"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue": {
     "auth_ref": [
      "r284",
      "r286",
      "r887"
     ],
     "calculation": {
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesDebtSecurities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One",
        "terseLabel": "Less than one year"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtSecurities": {
     "auth_ref": [
      "r278",
      "r281",
      "r328",
      "r871"
     ],
     "calculation": {
      "http://www.eversource.com/role/MARKETABLESECURITIESAvailableforSaleDebtSecuritiesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis",
       "weight": 1.0
      },
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Available-for-sale",
        "terseLabel": "Fair Value",
        "totalLabel": "Total Debt Securities"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtSecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESAvailableforSaleDebtSecuritiesDetails",
      "http://www.eversource.com/role/MARKETABLESECURITIESContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AwardTypeAxis": {
     "auth_ref": [
      "r612",
      "r623"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of award under share-based payment arrangement.",
        "label": "Award Type [Axis]",
        "terseLabel": "Award Type [Axis]"
       }
      }
     },
     "localname": "AwardTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BalanceSheetLocationAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by location on balance sheet (statement of financial position).",
        "label": "Balance Sheet Location [Axis]",
        "terseLabel": "Balance Sheet Location [Axis]"
       }
      }
     },
     "localname": "BalanceSheetLocationAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEversourceandNSTARElectricBostonHarborCivilActionDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BalanceSheetLocationDomain": {
     "auth_ref": [
      "r723",
      "r727"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Location in the balance sheet (statement of financial position).",
        "label": "Balance Sheet Location [Domain]",
        "terseLabel": "Balance Sheet Location [Domain]"
       }
      }
     },
     "localname": "BalanceSheetLocationDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEversourceandNSTARElectricBostonHarborCivilActionDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_BasisOfAccountingPolicyPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy for basis of accounting, or basis of presentation, used to prepare the financial statements (for example, US Generally Accepted Accounting Principles, Other Comprehensive Basis of Accounting, IFRS).",
        "label": "Basis of Accounting, Policy [Policy Text Block]",
        "terseLabel": "Basis of Presentation"
       }
      }
     },
     "localname": "BasisOfAccountingPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_BuildingMember": {
     "auth_ref": [
      "r352"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Facility held for productive use including, but not limited to, office, production, storage and distribution facilities.",
        "label": "Building [Member]",
        "terseLabel": "Buildings"
       }
      }
     },
     "localname": "BuildingMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_BusinessAcquisitionAcquireeDomain": {
     "auth_ref": [
      "r591",
      "r604"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Identification of the acquiree in a material business combination (or series of individually immaterial business combinations), which may include the name or other type of identification of the acquiree.",
        "label": "Business Acquisition, Acquiree [Domain]",
        "terseLabel": "Business Acquisition, Acquiree [Domain]"
       }
      }
     },
     "localname": "BusinessAcquisitionAcquireeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails",
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails",
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSScheduleofProFormaInformationDetails",
      "http://www.eversource.com/role/GOODWILLNarrativeDetails",
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_BusinessAcquisitionAxis": {
     "auth_ref": [
      "r591",
      "r604",
      "r685",
      "r686"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by business combination or series of individually immaterial business combinations.",
        "label": "Business Acquisition [Axis]",
        "terseLabel": "Business Acquisition [Axis]"
       }
      }
     },
     "localname": "BusinessAcquisitionAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails",
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails",
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSScheduleofProFormaInformationDetails",
      "http://www.eversource.com/role/GOODWILLNarrativeDetails",
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BusinessAcquisitionLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Business Acquisition [Line Items]",
        "terseLabel": "Business Acquisition [Line Items]"
       }
      }
     },
     "localname": "BusinessAcquisitionLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails",
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails",
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSScheduleofProFormaInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic": {
     "auth_ref": [
      "r683",
      "r684"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.",
        "label": "Business Acquisition, Pro Forma Earnings Per Share, Basic",
        "terseLabel": "Basic EPS (in dollars per share)"
       }
      }
     },
     "localname": "BusinessAcquisitionProFormaEarningsPerShareBasic",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSScheduleofProFormaInformationDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted": {
     "auth_ref": [
      "r683",
      "r684"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.",
        "label": "Business Acquisition, Pro Forma Earnings Per Share, Diluted",
        "terseLabel": "Diluted EPS (in dollars per share)"
       }
      }
     },
     "localname": "BusinessAcquisitionProFormaEarningsPerShareDiluted",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSScheduleofProFormaInformationDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_BusinessAcquisitionProFormaInformationTextBlock": {
     "auth_ref": [
      "r683",
      "r684"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of pro forma results of operations for a material business acquisition or series of individually immaterial business acquisitions that are material in the aggregate.",
        "label": "Business Acquisition, Pro Forma Information [Table Text Block]",
        "terseLabel": "Summary of Unaudited Pro Forma Financial Information"
       }
      }
     },
     "localname": "BusinessAcquisitionProFormaInformationTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax": {
     "auth_ref": [
      "r683",
      "r684"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after tax of pro forma income from continuing operations as if the business combination had been completed at the beginning of a period.",
        "label": "Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax",
        "terseLabel": "Pre-tax income"
       }
      }
     },
     "localname": "BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss": {
     "auth_ref": [
      "r683",
      "r684"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.",
        "label": "Business Acquisition, Pro Forma Net Income (Loss)",
        "terseLabel": "Net Income Attributable to Common Shareholders"
       }
      }
     },
     "localname": "BusinessAcquisitionsProFormaNetIncomeLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSScheduleofProFormaInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessAcquisitionsProFormaRevenue": {
     "auth_ref": [
      "r683",
      "r684"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.",
        "label": "Business Acquisition, Pro Forma Revenue",
        "terseLabel": "Operating revenues",
        "verboseLabel": "Operating Revenues"
       }
      }
     },
     "localname": "BusinessAcquisitionsProFormaRevenue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails",
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSScheduleofProFormaInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationConsiderationTransferred1": {
     "auth_ref": [
      "r691",
      "r692",
      "r694"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.",
        "label": "Business Combination, Consideration Transferred",
        "terseLabel": "Purchase price",
        "verboseLabel": "Consideration transferred"
       }
      }
     },
     "localname": "BusinessCombinationConsiderationTransferred1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationContingentConsiderationLiability": {
     "auth_ref": [
      "r690",
      "r693",
      "r696"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of liability recognized arising from contingent consideration in a business combination.",
        "label": "Business Combination, Contingent Consideration, Liability",
        "terseLabel": "Contingent liability for future refund to customers"
       }
      }
     },
     "localname": "BusinessCombinationContingentConsiderationLiability",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationDisclosureTextBlock": {
     "auth_ref": [
      "r698"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities. The disclosure may include leverage buyout transactions (as applicable).",
        "label": "Business Combination Disclosure [Text Block]",
        "terseLabel": "ACQUISITION OF ASSETS OF COLUMBIA GAS OF MASSACHUSETTS"
       }
      }
     },
     "localname": "BusinessCombinationDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTS"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets": {
     "auth_ref": [
      "r688"
     ],
     "calculation": {
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails": {
       "order": 7.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer, acquired at the acquisition date.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets",
        "terseLabel": "Current Assets"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities": {
     "auth_ref": [
      "r688"
     ],
     "calculation": {
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of liabilities due within one year or within the normal operating cycle, if longer, assumed at the acquisition date.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities",
        "negatedTerseLabel": "Other Current Liabilities"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill": {
     "auth_ref": [
      "r688"
     ],
     "calculation": {
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of intangible assets, excluding goodwill, acquired at the acquisition date.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill",
        "terseLabel": "Other Noncurrent Assets, excluding Goodwill"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment": {
     "auth_ref": [
      "r687",
      "r688"
     ],
     "calculation": {
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of property, plant, and equipment recognized as of the acquisition date.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment",
        "terseLabel": "PP&amp;E"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet": {
     "auth_ref": [
      "r688"
     ],
     "calculation": {
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net",
        "totalLabel": "Cash Purchase Price"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationSegmentAllocationTableTextBlock": {
     "auth_ref": [
      "r697"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of goodwill in a business combination.",
        "label": "Business Combination, Segment Allocation [Table Text Block]",
        "terseLabel": "Summary of Goodwill by Reportable Segment"
       }
      }
     },
     "localname": "BusinessCombinationSegmentAllocationTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/GOODWILLTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed": {
     "auth_ref": [
      "r682"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "For transactions that are recognized separately from the acquisition of assets and assumptions of liabilities in the business combination, such as related to pre-existing relationships with the acquiree, this element represents the disclosure of the amount of acquisition related costs which have been expensed.",
        "label": "Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Cost Expensed",
        "terseLabel": "TSA and pre-TSA costs"
       }
      }
     },
     "localname": "BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAxis": {
     "auth_ref": [
      "r680"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosures related to transactions that are recognized separately from the acquisition of assets and assumptions of liabilities in the business combination by type of transaction.",
        "label": "Business Combination, Separately Recognized Transactions [Axis]",
        "terseLabel": "Business Combination, Separately Recognized Transactions [Axis]"
       }
      }
     },
     "localname": "BusinessCombinationSeparatelyRecognizedTransactionsAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsDomain": {
     "auth_ref": [
      "r680"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Type of transaction that is recognized separately from the acquisition of assets and assumptions of liabilities in a business combination by transaction.",
        "label": "Business Combination, Separately Recognized Transactions [Domain]",
        "terseLabel": "Business Combination, Separately Recognized Transactions [Domain]"
       }
      }
     },
     "localname": "BusinessCombinationSeparatelyRecognizedTransactionsDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsExpensesAndLossesRecognized": {
     "auth_ref": [
      "r681"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The expenses and losses recorded for each transaction with the acquiree that was recognized separately from the acquisition of assets and assumptions of liabilities in the business combination.",
        "label": "Business Combination, Separately Recognized Transactions, Expenses and Losses Recognized",
        "terseLabel": "Energy Efficiency expense"
       }
      }
     },
     "localname": "BusinessCombinationSeparatelyRecognizedTransactionsExpensesAndLossesRecognized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Business Combinations [Abstract]",
        "terseLabel": "Business Combinations [Abstract]"
       }
      }
     },
     "localname": "BusinessCombinationsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_CapitalExpendituresIncurredButNotYetPaid": {
     "auth_ref": [
      "r157",
      "r158",
      "r159"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Future cash outflow to pay for purchases of fixed assets that have occurred.",
        "label": "Capital Expenditures Incurred but Not yet Paid",
        "terseLabel": "Plant additionsincluded in accounts payable (as of)"
       }
      }
     },
     "localname": "CapitalExpendituresIncurredButNotYetPaid",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSupplementalCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CapitalizationLongtermDebtAndEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Capitalization, Long-term Debt and Equity [Abstract]",
        "terseLabel": "Capitalization:"
       }
      }
     },
     "localname": "CapitalizationLongtermDebtAndEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CarryingReportedAmountFairValueDisclosureMember": {
     "auth_ref": [
      "r770",
      "r771"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measured as reported on the statement of financial position (balance sheet).",
        "label": "Reported Value Measurement [Member]",
        "terseLabel": "Fair Value Adjustment",
        "verboseLabel": "Carrying Amount"
       }
      }
     },
     "localname": "CarryingReportedAmountFairValueDisclosureMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_Cash": {
     "auth_ref": [
      "r44",
      "r826",
      "r929",
      "r930"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 1.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Excludes cash and cash equivalents within disposal group and discontinued operation.",
        "label": "Cash",
        "terseLabel": "Cash",
        "verboseLabel": "Cash as reported on the Balance Sheets"
       }
      }
     },
     "localname": "Cash",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashAndCashEquivalentsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.",
        "label": "Cash and Cash Equivalents [Member]",
        "verboseLabel": "Money Market Funds"
       }
      }
     },
     "localname": "CashAndCashEquivalentsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CashAndCashEquivalentsPolicyTextBlock": {
     "auth_ref": [
      "r23",
      "r155"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy for cash and cash equivalents, including the policy for determining which items are treated as cash equivalents. Other information that may be disclosed includes (1) the nature of any restrictions on the entity's use of its cash and cash equivalents, (2) whether the entity's cash and cash equivalents are insured or expose the entity to credit risk, (3) the classification of any negative balance accounts (overdrafts), and (4) the carrying basis of cash equivalents (for example, at cost) and whether the carrying amount of cash equivalents approximates fair value.",
        "label": "Cash and Cash Equivalents, Policy [Policy Text Block]",
        "terseLabel": "Cash"
       }
      }
     },
     "localname": "CashAndCashEquivalentsPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents": {
     "auth_ref": [
      "r145",
      "r154",
      "r160"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage. Excludes amount for disposal group and discontinued operations. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.",
        "label": "Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents",
        "periodEndLabel": "Cash and Restricted Cash - End of Year",
        "periodStartLabel": "Cash and Restricted Cash - Beginning of Year",
        "terseLabel": "Cash and Restricted Cash as reported on the Statements of Cash Flows"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect": {
     "auth_ref": [
      "r145",
      "r781"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in cash, cash equivalents, and cash and cash equivalents restricted to withdrawal or usage; including effect from exchange rate change. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.",
        "label": "Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect",
        "terseLabel": "Net (Decrease)/Increase in Cash and Restricted Cash",
        "totalLabel": "Net (Decrease)/Increase in Cash and Restricted Cash"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries": {
     "auth_ref": [
      "r176"
     ],
     "calculation": {
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": 8.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This element represents disclosure of the aggregate cash dividends paid to the entity by consolidated subsidiaries.",
        "label": "SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Consolidated Subsidiaries",
        "terseLabel": "Cash Dividends Received from Subsidiaries"
       }
      }
     },
     "localname": "CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths": {
     "auth_ref": [
      "r738"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.",
        "label": "Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months",
        "negatedTerseLabel": "Pre-tax amount reclassified from AOCI as a decrease to net income"
       }
      }
     },
     "localname": "CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ClassOfStockDomain": {
     "auth_ref": [
      "r163",
      "r166",
      "r208",
      "r209",
      "r211",
      "r214",
      "r216",
      "r226",
      "r227",
      "r228",
      "r308",
      "r414",
      "r419",
      "r420",
      "r421",
      "r427",
      "r428",
      "r463",
      "r464",
      "r468",
      "r472",
      "r772",
      "r971"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share of stock differentiated by the voting rights the holder receives. Examples include, but are not limited to, common stock, redeemable preferred stock, nonredeemable preferred stock, and convertible stock.",
        "label": "Class of Stock [Domain]",
        "terseLabel": "Class of Stock [Domain]"
       }
      }
     },
     "localname": "ClassOfStockDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ClassOfStockLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Class of Stock [Line Items]",
        "terseLabel": "Class of Stock [Line Items]"
       }
      }
     },
     "localname": "ClassOfStockLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESCommonSharesAuthorizedandIssuedDetails",
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONNarrativeDetails",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CommercialPaperMember": {
     "auth_ref": [
      "r410"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unsecured promissory note (generally negotiable) that provides institutions with short-term funds.",
        "label": "Commercial Paper [Member]",
        "terseLabel": "Commercial Paper"
       }
      }
     },
     "localname": "CommercialPaperMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTScheduleofDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommitmentsAndContingencies": {
     "auth_ref": [
      "r60",
      "r384",
      "r874",
      "r902"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 7.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the caption on the face of the balance sheet to indicate that the entity has entered into (1) purchase or supply arrangements that will require expending a portion of its resources to meet the terms thereof, and (2) is exposed to potential losses or, less frequently, gains, arising from (a) possible claims against a company's resources due to future performance under contract terms, and (b) possible losses or likely gains from uncertainties that will ultimately be resolved when one or more future events that are deemed likely to occur do occur or fail to occur.",
        "label": "Commitments and Contingencies",
        "terseLabel": "Commitments and Contingencies (Note 13)"
       }
      }
     },
     "localname": "CommitmentsAndContingencies",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CommitmentsAndContingenciesDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Commitments and Contingencies Disclosure [Abstract]",
        "terseLabel": "Commitments and Contingencies Disclosure [Abstract]"
       }
      }
     },
     "localname": "CommitmentsAndContingenciesDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_CommitmentsAndContingenciesDisclosureTextBlock": {
     "auth_ref": [
      "r378",
      "r380",
      "r382",
      "r397",
      "r933"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for commitments and contingencies.",
        "label": "Commitments and Contingencies Disclosure [Text Block]",
        "terseLabel": "COMMITMENTS AND CONTINGENCIES"
       }
      }
     },
     "localname": "CommitmentsAndContingenciesDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIES"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CommonStockDividendsPerShareCashPaid": {
     "auth_ref": [
      "r487"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate dividends paid during the period for each share of common stock outstanding.",
        "label": "Common Stock, Dividends, Per Share, Cash Paid",
        "terseLabel": "Dividends on Common Shares (in dollars per share)"
       }
      }
     },
     "localname": "CommonStockDividendsPerShareCashPaid",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITYParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_CommonStockMember": {
     "auth_ref": [
      "r186",
      "r187",
      "r750"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Stock that is subordinate to all other stock of the issuer.",
        "label": "Common Stock [Member]",
        "terseLabel": "Common Shares",
        "verboseLabel": "Common Stock"
       }
      }
     },
     "localname": "CommonStockMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommonStockParOrStatedValuePerShare": {
     "auth_ref": [
      "r32"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Face amount or stated value per share of common stock.",
        "label": "Common Stock, Par or Stated Value Per Share",
        "terseLabel": "Per share par value (in dollars per share)",
        "verboseLabel": "Par value of Common Shares (in dollars per share)"
       }
      }
     },
     "localname": "CommonStockParOrStatedValuePerShare",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESCommonSharesAuthorizedandIssuedDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITYParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_CommonStockSharesAuthorized": {
     "auth_ref": [
      "r32"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The maximum number of common shares permitted to be issued by an entity's charter and bylaws.",
        "label": "Common Stock, Shares Authorized",
        "terseLabel": "Authorized (in shares)"
       }
      }
     },
     "localname": "CommonStockSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESCommonSharesAuthorizedandIssuedDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockSharesIssued": {
     "auth_ref": [
      "r32"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.",
        "label": "Common Stock, Shares, Issued",
        "terseLabel": "Issued (in shares)"
       }
      }
     },
     "localname": "CommonStockSharesIssued",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESCommonSharesAuthorizedandIssuedDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockSharesOutstanding": {
     "auth_ref": [
      "r32",
      "r479"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.",
        "label": "Common Stock, Shares, Outstanding",
        "periodEndLabel": "Ending balance (in shares)",
        "periodStartLabel": "Beginning balance (in shares)",
        "terseLabel": "Common stock outstanding (in shares)"
       }
      }
     },
     "localname": "CommonStockSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockValue": {
     "auth_ref": [
      "r32",
      "r826"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 1.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.",
        "label": "Common Stock, Value, Issued",
        "terseLabel": "Common Shares",
        "verboseLabel": "Common Shares"
       }
      }
     },
     "localname": "CommonStockValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CompensationAndEmployeeBenefitPlansTextBlock": {
     "auth_ref": [
      "r512",
      "r515",
      "r609",
      "r633"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for an entity's employee compensation and benefit plans, including, but not limited to, postemployment and postretirement benefit plans, defined benefit pension plans, defined contribution plans, non-qualified and supplemental benefit plans, deferred compensation, share-based compensation, life insurance, severance, health care, unemployment and other benefit plans.",
        "label": "Compensation and Employee Benefit Plans [Text Block]",
        "terseLabel": "EMPLOYEE BENEFITS"
       }
      }
     },
     "localname": "CompensationAndEmployeeBenefitPlansTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITS"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ComponentsOfDeferredTaxLiabilitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Components of Deferred Tax Liabilities [Abstract]",
        "terseLabel": "Regulatory Amounts:"
       }
      }
     },
     "localname": "ComponentsOfDeferredTaxLiabilitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ComprehensiveIncomeNetOfTax": {
     "auth_ref": [
      "r102",
      "r104",
      "r105",
      "r118",
      "r880",
      "r908"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.",
        "label": "Comprehensive Income (Loss), Net of Tax, Attributable to Parent",
        "terseLabel": "Comprehensive Income",
        "totalLabel": "Comprehensive Income Attributable to Common Shareholders"
       }
      }
     },
     "localname": "ComprehensiveIncomeNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFCOMPREHENSIVEINCOMEDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMPREHENSIVEINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest": {
     "auth_ref": [
      "r102",
      "r104",
      "r117",
      "r701",
      "r702",
      "r718",
      "r879",
      "r907"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME": {
       "order": 3.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income (loss) and other comprehensive income (loss), attributable to noncontrolling interests. Excludes changes in equity resulting from investments by owners and distributions to owners.",
        "label": "Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest",
        "negatedLabel": "Comprehensive Income Attributable to Noncontrolling Interests"
       }
      }
     },
     "localname": "ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ComprehensiveIncomeNoteTextBlock": {
     "auth_ref": [
      "r116",
      "r128",
      "r878",
      "r906"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for comprehensive income, which includes, but is not limited to, 1) the amount of income tax expense or benefit allocated to each component of other comprehensive income, including reclassification adjustments, 2) the reclassification adjustments for each classification of other comprehensive income and 3) the ending accumulated balances for each component of comprehensive income.",
        "label": "Comprehensive Income (Loss) Note [Text Block]",
        "terseLabel": "ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS)"
       }
      }
     },
     "localname": "ComprehensiveIncomeNoteTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSS"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CondensedFinancialInformationOfParentCompanyOnlyDisclosureTextBlock": {
     "auth_ref": [
      "r5",
      "r175",
      "r699"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for condensed financial information, including the financial position, cash flows, and the results of operations of the registrant (parent company) as of the same dates or for the same periods for which audited consolidated financial statements are being presented. Alternatively, the details of this disclosure can be reported by the specific parent company taxonomy elements, indicating the appropriate date and period contexts in an instance document.",
        "label": "Condensed Financial Information of Parent Company Only Disclosure [Text Block]",
        "terseLabel": "SCHEDULE I - FINANCIAL INFORMATION OF REGISTRANT"
       }
      }
     },
     "localname": "CondensedFinancialInformationOfParentCompanyOnlyDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANT"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ConstructionInProgressMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.",
        "label": "Construction in Progress [Member]",
        "terseLabel": "Construction in Progress"
       }
      }
     },
     "localname": "ConstructionInProgressMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ContractualObligation": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.",
        "label": "Contractual Obligation",
        "terseLabel": "Total construction contract cost"
       }
      }
     },
     "localname": "ContractualObligation",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CorporateBondSecuritiesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This category includes information about long-term debt securities that are issued by either a domestic or foreign corporate business entity with a date certain promise of repayment and a return to the holder for the time value of money (for example, variable or fixed interest, original issue discount).",
        "label": "Corporate Bond Securities [Member]",
        "terseLabel": "Corporate Debt Securities"
       }
      }
     },
     "localname": "CorporateBondSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CorporateNonSegmentMember": {
     "auth_ref": [
      "r247",
      "r248",
      "r249",
      "r250",
      "r252",
      "r258",
      "r260"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Corporate headquarters or functional department that may not earn revenues or may earn revenues that are only incidental to the activities of the entity and is not considered an operating segment.",
        "label": "Corporate, Non-Segment [Member]",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "CorporateNonSegmentMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CreditFacilityAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of credit facility. Credit facilities provide capital to borrowers without the need to structure a loan for each borrowing.",
        "label": "Credit Facility [Axis]",
        "terseLabel": "Credit Facility [Axis]"
       }
      }
     },
     "localname": "CreditFacilityAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESGuaranteesandObligationsNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CreditFacilityDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Type of credit facility. Credit facilities provide capital to borrowers without the need to structure a loan for each borrowing.",
        "label": "Credit Facility [Domain]",
        "terseLabel": "Credit Facility [Domain]"
       }
      }
     },
     "localname": "CreditFacilityDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESGuaranteesandObligationsNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Current Federal, State and Local, Tax Expense (Benefit) [Abstract]",
        "terseLabel": "Current Income Taxes:"
       }
      }
     },
     "localname": "CurrentFederalStateAndLocalTaxExpenseBenefitAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CurrentFederalTaxExpenseBenefit": {
     "auth_ref": [
      "r167",
      "r662",
      "r670"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_CurrentIncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.",
        "label": "Current Federal Tax Expense (Benefit)",
        "terseLabel": "Federal"
       }
      }
     },
     "localname": "CurrentFederalTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CurrentIncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r167",
      "r662",
      "r670",
      "r672"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.",
        "label": "Current Income Tax Expense (Benefit)",
        "totalLabel": "Total Current"
       }
      }
     },
     "localname": "CurrentIncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CurrentStateAndLocalTaxExpenseBenefit": {
     "auth_ref": [
      "r167",
      "r662",
      "r670"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_CurrentIncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations.",
        "label": "Current State and Local Tax Expense (Benefit)",
        "terseLabel": "State"
       }
      }
     },
     "localname": "CurrentStateAndLocalTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Disclosure [Abstract]",
        "terseLabel": "Debt Disclosure [Abstract]"
       }
      }
     },
     "localname": "DebtDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtInstrumentAxis": {
     "auth_ref": [
      "r26",
      "r27",
      "r28",
      "r165",
      "r175",
      "r429",
      "r430",
      "r431",
      "r432",
      "r433",
      "r434",
      "r435",
      "r436",
      "r437",
      "r438",
      "r439",
      "r440",
      "r441",
      "r442",
      "r443",
      "r444",
      "r445",
      "r448",
      "r449",
      "r450",
      "r451",
      "r795",
      "r868",
      "r869",
      "r894"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of debt instrument, including, but not limited to, draws against credit facilities.",
        "label": "Debt Instrument [Axis]",
        "terseLabel": "Debt Instrument [Axis]"
       }
      }
     },
     "localname": "DebtInstrumentAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESIncomeStatementDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESNarrativeDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtInstrumentBasisSpreadOnVariableRate1": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage points added to the reference rate to compute the variable rate on the debt instrument.",
        "label": "Debt Instrument, Basis Spread on Variable Rate",
        "terseLabel": "Basis spread on compounded SOFR"
       }
      }
     },
     "localname": "DebtInstrumentBasisSpreadOnVariableRate1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DebtInstrumentFaceAmount": {
     "auth_ref": [
      "r429",
      "r448",
      "r449",
      "r792",
      "r795",
      "r796"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Face (par) amount of debt instrument at time of issuance.",
        "label": "Debt Instrument, Face Amount",
        "verboseLabel": "Amount of securitized rate reduction bonds issued"
       }
      }
     },
     "localname": "DebtInstrumentFaceAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESNarrativeDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtInstrumentInterestRateStatedPercentage": {
     "auth_ref": [
      "r57",
      "r430"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Contractual interest rate for funds borrowed, under the debt agreement.",
        "label": "Debt Instrument, Interest Rate, Stated Percentage",
        "terseLabel": "Interest rate"
       }
      }
     },
     "localname": "DebtInstrumentInterestRateStatedPercentage",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DebtInstrumentLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Debt Instrument [Line Items]",
        "terseLabel": "Debt Instrument [Line Items]"
       }
      }
     },
     "localname": "DebtInstrumentLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtInstrumentNameDomain": {
     "auth_ref": [
      "r58",
      "r165",
      "r175",
      "r429",
      "r430",
      "r431",
      "r432",
      "r433",
      "r434",
      "r435",
      "r436",
      "r437",
      "r438",
      "r439",
      "r440",
      "r441",
      "r442",
      "r443",
      "r444",
      "r445",
      "r448",
      "r449",
      "r450",
      "r451",
      "r795"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The name for the particular debt instrument or borrowing that distinguishes it from other debt instruments or borrowings, including draws against credit facilities.",
        "label": "Debt Instrument, Name [Domain]",
        "terseLabel": "Debt Instrument, Name [Domain]"
       }
      }
     },
     "localname": "DebtInstrumentNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESIncomeStatementDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESNarrativeDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DebtInstrumentTable": {
     "auth_ref": [
      "r58",
      "r165",
      "r175",
      "r429",
      "r430",
      "r431",
      "r432",
      "r433",
      "r434",
      "r435",
      "r436",
      "r437",
      "r438",
      "r439",
      "r440",
      "r441",
      "r442",
      "r443",
      "r444",
      "r445",
      "r446",
      "r448",
      "r449",
      "r450",
      "r451",
      "r480",
      "r484",
      "r485",
      "r486",
      "r791",
      "r792",
      "r795",
      "r796",
      "r893"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A table or schedule providing information pertaining to long-term debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the company, if longer.",
        "label": "Schedule of Long-term Debt Instruments [Table]",
        "terseLabel": "Schedule of Long-term Debt Instruments [Table]"
       }
      }
     },
     "localname": "DebtInstrumentTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtInstrumentTerm": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Debt Instrument, Term",
        "terseLabel": "Debt instrument term"
       }
      }
     },
     "localname": "DebtInstrumentTerm",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet": {
     "auth_ref": [
      "r436",
      "r791",
      "r792",
      "r793",
      "r794",
      "r796"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after accumulated amortization, of debt discount (premium).",
        "label": "Debt Instrument, Unamortized Discount (Premium), Net",
        "negatedTerseLabel": "Unamortized Premiums and Discounts, Net"
       }
      }
     },
     "localname": "DebtInstrumentUnamortizedDiscountPremiumNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtWeightedAverageInterestRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average interest rate of debt outstanding.",
        "label": "Debt, Weighted Average Interest Rate",
        "terseLabel": "Weighted average interest rate"
       }
      }
     },
     "localname": "DebtWeightedAverageInterestRate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DeferredCompensationCashbasedArrangementsLiabilityClassifiedNoncurrent": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate carrying value as of the balance sheet date of the liabilities for deferred compensation arrangements payable after one year (or the normal operating cycle, if longer). Represents currently earned compensation under cash arrangements (such as a profit-sharing plan, rabbi trust, and employee contract--excluding equity-based arrangements) that is not actually paid until a later date.",
        "label": "Deferred Compensation Cash-based Arrangements, Liability, Classified, Noncurrent",
        "terseLabel": "Actuarially-Determined Liability"
       }
      }
     },
     "localname": "DeferredCompensationCashbasedArrangementsLiabilityClassifiedNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofOtherRetirementBenefitsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredFederalIncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r167",
      "r663",
      "r670"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DeferredIncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of deferred federal income tax expense (benefit) pertaining to income (loss) from continuing operations.",
        "label": "Deferred Federal Income Tax Expense (Benefit)",
        "terseLabel": "Federal"
       }
      }
     },
     "localname": "DeferredFederalIncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredFederalStateAndLocalTaxExpenseBenefitAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Deferred Federal, State and Local, Tax Expense (Benefit) [Abstract]",
        "terseLabel": "Deferred Income Taxes, Net:"
       }
      }
     },
     "localname": "DeferredFederalStateAndLocalTaxExpenseBenefitAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DeferredFinanceCostsNet": {
     "auth_ref": [
      "r48",
      "r436",
      "r793"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.",
        "label": "Debt Issuance Costs, Net",
        "negatedTerseLabel": "Unamortized Debt Issuance Costs"
       }
      }
     },
     "localname": "DeferredFinanceCostsNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredIncomeTaxAssetsNet": {
     "auth_ref": [
      "r637",
      "r638"
     ],
     "calculation": {
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, with jurisdictional netting.",
        "label": "Deferred Income Tax Assets, Net",
        "terseLabel": "Accumulated Deferred Income Taxes"
       }
      }
     },
     "localname": "DeferredIncomeTaxAssetsNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredIncomeTaxChargesMember": {
     "auth_ref": [
      "r951",
      "r956",
      "r958",
      "r959"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate action of a regulator resulting in capitalization or accrual of income taxes.",
        "label": "Deferred Income Tax Charge [Member]",
        "terseLabel": "Income Taxes, Net"
       }
      }
     },
     "localname": "DeferredIncomeTaxChargesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DeferredIncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r152",
      "r167",
      "r663",
      "r670",
      "r671",
      "r672"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      },
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      },
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.",
        "label": "Deferred Income Tax Expense (Benefit)",
        "terseLabel": "Deferred Income Taxes",
        "totalLabel": "Total Deferred"
       }
      }
     },
     "localname": "DeferredIncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredIncomeTaxLiabilitiesNet": {
     "auth_ref": [
      "r637",
      "r638"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 1.0,
       "parentTag": "us-gaap_LiabilitiesOtherThanLongtermDebtNoncurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences with jurisdictional netting.",
        "label": "Deferred Income Tax Liabilities, Net",
        "terseLabel": "Accumulated Deferred Income Taxes"
       }
      }
     },
     "localname": "DeferredIncomeTaxLiabilitiesNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r167",
      "r663",
      "r670"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DeferredIncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of deferred state and local tax expense (benefit) pertaining to income (loss) from continuing operations.",
        "label": "Deferred State and Local Income Tax Expense (Benefit)",
        "terseLabel": "State"
       }
      }
     },
     "localname": "DeferredStateAndLocalIncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsDerivativeInstruments": {
     "auth_ref": [
      "r660",
      "r661"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from derivative instruments.",
        "label": "Deferred Tax Assets, Derivative Instruments",
        "terseLabel": "Derivative Liabilities"
       }
      }
     },
     "localname": "DeferredTaxAssetsDerivativeInstruments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsGross": {
     "auth_ref": [
      "r653"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DeferredTaxAssetsNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.",
        "label": "Deferred Tax Assets, Gross",
        "totalLabel": "Total Deferred Tax Assets"
       }
      }
     },
     "localname": "DeferredTaxAssetsGross",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsNet": {
     "auth_ref": [
      "r655"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.",
        "label": "Deferred Tax Assets, Net of Valuation Allowance",
        "totalLabel": "Net Deferred Tax Assets"
       }
      }
     },
     "localname": "DeferredTaxAssetsNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsOperatingLossCarryforwards": {
     "auth_ref": [
      "r660",
      "r661"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.",
        "label": "Deferred Tax Assets, Operating Loss Carryforwards",
        "terseLabel": "Net Operating Loss Carryforwards"
       }
      }
     },
     "localname": "DeferredTaxAssetsOperatingLossCarryforwards",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsOther": {
     "auth_ref": [
      "r660",
      "r661"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 8.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.",
        "label": "Deferred Tax Assets, Other",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "DeferredTaxAssetsOther",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsRegulatoryAssetsAndLiabilities": {
     "auth_ref": [
      "r660",
      "r661"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences derived regulatory assets and liabilities.",
        "label": "Deferred Tax Assets, Regulatory Assets and Liabilities",
        "terseLabel": "Regulatory Deferrals - Liabilities"
       }
      }
     },
     "localname": "DeferredTaxAssetsRegulatoryAssetsAndLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits": {
     "auth_ref": [
      "r660",
      "r661"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from compensation and benefits costs.",
        "label": "Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits",
        "terseLabel": "Employee Benefits"
       }
      }
     },
     "localname": "DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits [Abstract]",
        "terseLabel": "Deferred Tax Assets:"
       }
      }
     },
     "localname": "DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts": {
     "auth_ref": [
      "r660",
      "r661"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary difference from allowance for credit loss on accounts receivable.",
        "label": "Deferred Tax Asset, Tax Deferred Expense, Reserve and Accrual, Accounts Receivable, Allowance for Credit Loss",
        "terseLabel": "Allowance for Uncollectible Accounts"
       }
      }
     },
     "localname": "DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsValuationAllowance": {
     "auth_ref": [
      "r654"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DeferredTaxAssetsNet",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.",
        "label": "Deferred Tax Assets, Valuation Allowance",
        "terseLabel": "Less: \u00a0Valuation Allowance"
       }
      }
     },
     "localname": "DeferredTaxAssetsValuationAllowance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxLiabilities": {
     "auth_ref": [
      "r638",
      "r655"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences without jurisdictional netting.",
        "label": "Deferred Tax Liabilities, Net",
        "totalLabel": "Total Deferred Tax Liabilities"
       }
      }
     },
     "localname": "DeferredTaxLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxLiabilitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Deferred Tax Liabilities, Gross [Abstract]",
        "terseLabel": "Deferred Tax Liabilities:"
       }
      }
     },
     "localname": "DeferredTaxLiabilitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DeferredTaxLiabilitiesOther": {
     "auth_ref": [
      "r660",
      "r661"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 7.0,
       "parentTag": "us-gaap_DeferredTaxLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of deferred tax liability attributable to taxable temporary differences classified as other.",
        "label": "Deferred Tax Liabilities, Other",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "DeferredTaxLiabilitiesOther",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment": {
     "auth_ref": [
      "r660",
      "r661"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DeferredTaxLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment.",
        "label": "Deferred Tax Liabilities, Property, Plant and Equipment",
        "terseLabel": "Accelerated Depreciation and Other \u00a0\u00a0Plant-Related Differences"
       }
      }
     },
     "localname": "DeferredTaxLiabilitiesPropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation": {
     "auth_ref": [
      "r549"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level.",
        "label": "Defined Benefit Plan, Accumulated Benefit Obligation",
        "terseLabel": "Accumulated benefit obligation"
       }
      }
     },
     "localname": "DefinedBenefitPlanAccumulatedBenefitObligation",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofFundedStatusDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax": {
     "auth_ref": [
      "r97",
      "r561"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before tax, of accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.",
        "label": "Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax",
        "terseLabel": "Actuarial Loss"
       }
      }
     },
     "localname": "DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax": {
     "auth_ref": [
      "r97",
      "r561"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before tax, of accumulated other comprehensive (income) loss for cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).",
        "label": "Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax",
        "terseLabel": "Prior Service Cost"
       }
      }
     },
     "localname": "DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets": {
     "auth_ref": [
      "r531",
      "r586"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in plan assets of defined benefit plan from actual return (loss) determined by change in fair value of plan assets adjusted for contributions, benefit payments, and other expenses.",
        "label": "Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)",
        "terseLabel": "Actual Return on Plan Assets"
       }
      }
     },
     "localname": "DefinedBenefitPlanActualReturnOnPlanAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanActuarialGainLoss": {
     "auth_ref": [
      "r524"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan.",
        "label": "Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)",
        "terseLabel": "Actuarial Gain/(Loss)"
       }
      }
     },
     "localname": "DefinedBenefitPlanActuarialGainLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses": {
     "auth_ref": [
      "r518",
      "r556",
      "r580",
      "r586",
      "r587"
     ],
     "calculation": {
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan.",
        "label": "Defined Benefit Plan, Amortization of Gain (Loss)",
        "negatedTerseLabel": "Actuarial Loss"
       }
      }
     },
     "localname": "DefinedBenefitPlanAmortizationOfGainsLosses",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit": {
     "auth_ref": [
      "r518",
      "r557",
      "r581",
      "r586",
      "r587"
     ],
     "calculation": {
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan.",
        "label": "Defined Benefit Plan, Amortization of Prior Service Cost (Credit)",
        "terseLabel": "Prior Service Cost/(Credit)"
       }
      }
     },
     "localname": "DefinedBenefitPlanAmortizationOfPriorServiceCostCredit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate": {
     "auth_ref": [
      "r563"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan.",
        "label": "Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate",
        "terseLabel": "Discount Rate"
       }
      }
     },
     "localname": "DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease": {
     "auth_ref": [
      "r564"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average rate increase of compensation, used to determine benefit obligation of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan.",
        "label": "Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase",
        "terseLabel": "Compensation/Progression Rate"
       }
      }
     },
     "localname": "DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate": {
     "auth_ref": [
      "r563"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan.",
        "label": "Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate",
        "terseLabel": "Discount Rate"
       }
      }
     },
     "localname": "DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssumptionsusedToCalculatePensionandSERPandPBOPDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets": {
     "auth_ref": [
      "r565",
      "r585"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan.",
        "label": "Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets",
        "terseLabel": "Expected Long-Term Rate of Return",
        "verboseLabel": "Expected long-term rate of return"
       }
      }
     },
     "localname": "DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssumptionsusedToCalculatePensionandSERPandPBOPDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease": {
     "auth_ref": [
      "r564"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average rate of compensation increase used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan.",
        "label": "Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase",
        "terseLabel": "Compensation/Progression Rate"
       }
      }
     },
     "localname": "DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssumptionsusedToCalculatePensionandSERPandPBOPDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DefinedBenefitPlanBenefitObligation": {
     "auth_ref": [
      "r519"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.",
        "label": "Defined Benefit Plan, Benefit Obligation",
        "negatedPeriodEndLabel": "Benefit Obligation as of End of Year",
        "negatedPeriodStartLabel": "Benefit Obligation as of Beginning of Year"
       }
      }
     },
     "localname": "DefinedBenefitPlanBenefitObligation",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid": {
     "auth_ref": [
      "r526",
      "r588"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of payment to participant of defined benefit plan which decreases benefit obligation. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services.",
        "label": "Defined Benefit Plan, Benefit Obligation, Benefits Paid",
        "terseLabel": "Benefits Paid"
       }
      }
     },
     "localname": "DefinedBenefitPlanBenefitObligationBenefitsPaid",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsBenefitObligation": {
     "auth_ref": [
      "r528"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase in benefit obligation of defined benefit plan from business combination.",
        "label": "Defined Benefit Plan, Benefit Obligation, Business Combination",
        "negatedTerseLabel": "Increase due to acquisition of CMA"
       }
      }
     },
     "localname": "DefinedBenefitPlanBusinessCombinationsAndAcquisitionsBenefitObligation",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets": {
     "auth_ref": [
      "r536"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase in plan assets of defined benefit plan from business combination.",
        "label": "Defined Benefit Plan, Plan Assets, Business Combination",
        "terseLabel": "Increase due to acquisition of CMA"
       }
      }
     },
     "localname": "DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis": {
     "auth_ref": [
      "r541",
      "r542",
      "r543",
      "r544",
      "r545",
      "r546",
      "r547",
      "r548",
      "r568",
      "r586"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by defined benefit plan asset investment.",
        "label": "Defined Benefit Plan, Plan Assets, Category [Axis]",
        "terseLabel": "Defined Benefit Plan, Plan Assets, Category [Axis]"
       }
      }
     },
     "localname": "DefinedBenefitPlanByPlanAssetCategoriesAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]",
        "verboseLabel": "Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]"
       }
      }
     },
     "localname": "DefinedBenefitPlanChangeInBenefitObligationRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DefinedBenefitPlanContributionsByEmployer": {
     "auth_ref": [
      "r533",
      "r542",
      "r543",
      "r584",
      "r586",
      "r587"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of contribution received by defined benefit plan from employer which increases plan assets.",
        "label": "Defined Benefit Plan, Plan Assets, Contributions by Employer",
        "terseLabel": "Employer Contributions"
       }
      }
     },
     "localname": "DefinedBenefitPlanContributionsByEmployer",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanDisclosureLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Defined Benefit Plan Disclosure [Line Items]",
        "terseLabel": "Defined Benefit Plan Disclosure [Line Items]"
       }
      }
     },
     "localname": "DefinedBenefitPlanDisclosureLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssumptionsusedToCalculatePensionandSERPandPBOPDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofFundedStatusDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DefinedBenefitPlanEquitySecuritiesMember": {
     "auth_ref": [
      "r542",
      "r586"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Security representing ownership in corporation or other legal entity for which ownership is represented by share of stock, in which defined benefit plan asset is invested. Includes, but is not limited to, common stock, preferred stock, convertible security, stock right and stock warrant.",
        "label": "Defined Benefit Plan, Equity Securities [Member]",
        "terseLabel": "Equity securities",
        "verboseLabel": "Equity Securities"
       }
      }
     },
     "localname": "DefinedBenefitPlanEquitySecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DefinedBenefitPlanEquitySecuritiesNonUsMember": {
     "auth_ref": [
      "r542",
      "r543",
      "r586"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Security representing ownership in corporation or other legal entity, not domiciled in United States of America (US), for which ownership is represented by share of stock; in which defined benefit plan asset is invested. Includes, but is not limited to, common stock, preferred stock, convertible security, stock right and stock warrant.",
        "label": "Defined Benefit Plan, Equity Securities, Non-US [Member]",
        "terseLabel": "Non-United States"
       }
      }
     },
     "localname": "DefinedBenefitPlanEquitySecuritiesNonUsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DefinedBenefitPlanEquitySecuritiesUsMember": {
     "auth_ref": [
      "r542",
      "r543",
      "r586"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Security representing ownership in corporation or other legal entity, domiciled in United States of America (US), for which ownership is represented by share of stock; in which defined benefit plan asset is invested. Includes, but is not limited to, common stock, preferred stock, convertible security, stock right and stock warrant.",
        "label": "Defined Benefit Plan, Equity Securities, US [Member]",
        "terseLabel": "United States"
       }
      }
     },
     "localname": "DefinedBenefitPlanEquitySecuritiesUsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter": {
     "auth_ref": [
      "r550"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of benefit for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following current fiscal year.",
        "label": "Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years",
        "terseLabel": "2027 - 2031"
       }
      }
     },
     "localname": "DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofEstimatedFutureBenefitPaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths": {
     "auth_ref": [
      "r550"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of benefit for defined benefit plan expected to be paid in next fiscal year following current fiscal year.",
        "label": "Defined Benefit Plan, Expected Future Benefit Payment, Year One",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofEstimatedFutureBenefitPaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive": {
     "auth_ref": [
      "r550"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of benefit for defined benefit plan expected to be paid in fifth fiscal year following current fiscal year.",
        "label": "Defined Benefit Plan, Expected Future Benefit Payment, Year Five",
        "terseLabel": "2026"
       }
      }
     },
     "localname": "DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofEstimatedFutureBenefitPaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour": {
     "auth_ref": [
      "r550"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of benefit for defined benefit plan expected to be paid in fourth fiscal year following current fiscal year.",
        "label": "Defined Benefit Plan, Expected Future Benefit Payment, Year Four",
        "terseLabel": "2025"
       }
      }
     },
     "localname": "DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofEstimatedFutureBenefitPaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree": {
     "auth_ref": [
      "r550"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of benefit for defined benefit plan expected to be paid in third fiscal year following current fiscal year.",
        "label": "Defined Benefit Plan, Expected Future Benefit Payment, Year Three",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofEstimatedFutureBenefitPaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo": {
     "auth_ref": [
      "r550"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of benefit for defined benefit plan expected to be paid in second fiscal year following current fiscal year.",
        "label": "Defined Benefit Plan, Expected Future Benefit Payment, Year Two",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofEstimatedFutureBenefitPaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear": {
     "auth_ref": [
      "r551",
      "r587"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of contribution expected to be received by defined benefit plan from employer in next fiscal year following current fiscal year.",
        "label": "Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year",
        "terseLabel": "Estimated future employer contributions in next fiscal year"
       }
      }
     },
     "localname": "DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets": {
     "auth_ref": [
      "r518",
      "r555",
      "r579",
      "r586",
      "r587"
     ],
     "calculation": {
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan.",
        "label": "Defined Benefit Plan, Expected Return (Loss) on Plan Assets",
        "negatedTerseLabel": "Expected Return on Plan Assets"
       }
      }
     },
     "localname": "DefinedBenefitPlanExpectedReturnOnPlanAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanFairValueOfPlanAssets": {
     "auth_ref": [
      "r530",
      "r542",
      "r543",
      "r544",
      "r586"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.",
        "label": "Defined Benefit Plan, Plan Assets, Amount",
        "periodEndLabel": "Fair Value of Plan Assets as of End of Year",
        "periodStartLabel": "Fair Value of Plan Assets as of Beginning of Year",
        "verboseLabel": "Fair value of pension plan assets"
       }
      }
     },
     "localname": "DefinedBenefitPlanFairValueOfPlanAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanFundedStatusOfPlan": {
     "auth_ref": [
      "r516",
      "r539",
      "r586"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of funded (unfunded) status of defined benefit plan, measured as difference between fair value of plan assets and benefit obligation. Includes, but is not limited to, overfunded (underfunded) status.",
        "label": "Defined Benefit Plan, Funded (Unfunded) Status of Plan",
        "terseLabel": "Funded Status as of December 31st",
        "verboseLabel": "Funded status of plan"
       }
      }
     },
     "localname": "DefinedBenefitPlanFundedStatusOfPlan",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanFundedStatusOfPlanAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]",
        "terseLabel": "Defined Benefit Plan Costs:",
        "verboseLabel": "Change in Pension Plan Assets:"
       }
      }
     },
     "localname": "DefinedBenefitPlanFundedStatusOfPlanAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DefinedBenefitPlanInterestCost": {
     "auth_ref": [
      "r518",
      "r522",
      "r554",
      "r578",
      "r586",
      "r587"
     ],
     "calculation": {
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cost recognized for passage of time related to defined benefit plan.",
        "label": "Defined Benefit Plan, Interest Cost",
        "negatedTerseLabel": "Interest Cost",
        "terseLabel": "Interest Cost"
       }
      }
     },
     "localname": "DefinedBenefitPlanInterestCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost": {
     "auth_ref": [
      "r552",
      "r576",
      "r586",
      "r587"
     ],
     "calculation": {
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of net periodic benefit cost (credit) for defined benefit plan.",
        "label": "Defined Benefit Plan, Net Periodic Benefit Cost (Credit)",
        "totalLabel": "Total Net Periodic Benefit Plan Expense/(Income)"
       }
      }
     },
     "localname": "DefinedBenefitPlanNetPeriodicBenefitCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid": {
     "auth_ref": [
      "r535",
      "r588"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of payment to participant under defined benefit plan which decreases plan assets. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services.",
        "label": "Defined Benefit Plan, Plan Assets, Benefits Paid",
        "negatedTerseLabel": "Benefits Paid - Pension"
       }
      }
     },
     "localname": "DefinedBenefitPlanPlanAssetsBenefitsPaid",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage": {
     "auth_ref": [
      "r541",
      "r586"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.",
        "label": "Defined Benefit Plan, Plan Assets, Target Allocation, Percentage",
        "terseLabel": "Target Asset Allocation"
       }
      }
     },
     "localname": "DefinedBenefitPlanPlanAssetsTargetAllocationPercentage",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DefinedBenefitPlanRealEstateMember": {
     "auth_ref": [
      "r542",
      "r586"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Property composed of building, land and land improvement; in which defined benefit plan asset is invested.",
        "label": "Defined Benefit Plan, Real Estate [Member]",
        "terseLabel": "Real Assets"
       }
      }
     },
     "localname": "DefinedBenefitPlanRealEstateMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DefinedBenefitPlanServiceCost": {
     "auth_ref": [
      "r520",
      "r553",
      "r577",
      "r586",
      "r587"
     ],
     "calculation": {
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.",
        "label": "Defined Benefit Plan, Service Cost",
        "negatedTerseLabel": "Service Cost",
        "terseLabel": "Service Cost"
       }
      }
     },
     "localname": "DefinedBenefitPlanServiceCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1": {
     "auth_ref": [
      "r567"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ultimate trend rate for health care cost for defined benefit postretirement plan.",
        "label": "Defined Benefit Plan, Ultimate Health Care Cost Trend Rate",
        "terseLabel": "Ultimate rate"
       }
      }
     },
     "localname": "DefinedBenefitPlanUltimateHealthCareCostTrendRate1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations": {
     "auth_ref": [
      "r541"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage of actual investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.",
        "label": "Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage",
        "terseLabel": "Assumed Rate of Return"
       }
      }
     },
     "localname": "DefinedBenefitPlanWeightedAverageAssetAllocations",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable": {
     "auth_ref": [
      "r570",
      "r571",
      "r574",
      "r575",
      "r586"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosures and provisions pertaining to defined benefit pension plans or other postretirement defined benefit plans. The arrangements are generally based on terms and conditions stipulated by the entity, and which contain a promise by the employer to pay certain amounts or awards at designated future dates, including a period after retirement, upon compliance with stipulated requirements. Excludes disclosures pertaining to defined contribution plans.",
        "label": "Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table]",
        "terseLabel": "Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table]"
       }
      }
     },
     "localname": "DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofOtherRetirementBenefitsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]",
        "terseLabel": "Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]"
       }
      }
     },
     "localname": "DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofOtherRetirementBenefitsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DefinedContributionPlanCostRecognized": {
     "auth_ref": [
      "r589"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cost for defined contribution plan.",
        "label": "Defined Contribution Plan, Cost",
        "terseLabel": "Defined contribution plan, cost recognized"
       }
      }
     },
     "localname": "DefinedContributionPlanCostRecognized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofDefinedContributionPlansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedContributionPlanDisclosureLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Defined Contribution Plan Disclosure [Line Items]",
        "terseLabel": "Defined Contribution Plan Disclosure [Line Items]"
       }
      }
     },
     "localname": "DefinedContributionPlanDisclosureLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSDefinedContributionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofDefinedContributionPlansDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofEstimatedFutureBenefitPaymentsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.",
        "label": "Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay",
        "terseLabel": "Percentage of employees' pay (up to)"
       }
      }
     },
     "localname": "DefinedContributionPlanEmployerMatchingContributionPercent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSDefinedContributionPlanNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage employer matches of the employee's percentage contribution matched.",
        "label": "Defined Contribution Plan, Employer Matching Contribution, Percent of Match",
        "terseLabel": "Employer matching contribution (as a percentage)"
       }
      }
     },
     "localname": "DefinedContributionPlanEmployerMatchingContributionPercentOfMatch",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSDefinedContributionPlanNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DefinedContributionPlanTable": {
     "auth_ref": [
      "r589"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about defined contribution pension plans or defined contribution other postretirement plans, separately for pension plans and other postretirement benefit plans.",
        "label": "Defined Contribution Plan [Table]",
        "terseLabel": "Defined Contribution Plan [Table]"
       }
      }
     },
     "localname": "DefinedContributionPlanTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSDefinedContributionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofDefinedContributionPlansDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofEstimatedFutureBenefitPaymentsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DepositsAssetsCurrent": {
     "auth_ref": [
      "r48"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 9.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Carrying value of amounts transferred to third parties for security purposes that are expected to be returned or applied towards payment within one year or during the operating cycle, if shorter.",
        "label": "Deposits Assets, Current",
        "terseLabel": "Special Deposits"
       }
      }
     },
     "localname": "DepositsAssetsCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_Depreciation": {
     "auth_ref": [
      "r152",
      "r351"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      },
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 3.0,
       "parentTag": "us-gaap_OperatingExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.",
        "label": "Depreciation",
        "terseLabel": "Depreciation"
       }
      }
     },
     "localname": "Depreciation",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DepreciationDepletionAndAmortization": {
     "auth_ref": [
      "r152",
      "r237"
     ],
     "calculation": {
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_OperatingIncomeLoss",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.",
        "label": "Depreciation, Depletion and Amortization",
        "negatedTerseLabel": "Depreciation and Amortization"
       }
      }
     },
     "localname": "DepreciationDepletionAndAmortization",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeAssetFairValueGrossLiability": {
     "auth_ref": [
      "r74",
      "r82",
      "r725"
     ],
     "calculation": {
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of liability associated with financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.",
        "label": "Derivative Asset, Fair Value, Gross Liability",
        "negatedLabel": "Netting"
       }
      }
     },
     "localname": "DerivativeAssetFairValueGrossLiability",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeAssetLiabilityNetMeasurementInput": {
     "auth_ref": [
      "r758"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Value of input used to measure net derivative asset (liability).",
        "label": "Derivative Asset (Liability) Net, Measurement Input",
        "terseLabel": "Derivative measurement input"
       }
      }
     },
     "localname": "DerivativeAssetLiabilityNetMeasurementInput",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "us-gaap_DerivativeAssetsLiabilitiesAtFairValueNetByBalanceSheetClassificationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]",
        "terseLabel": "Current and Long-Term Derivative Assets"
       }
      }
     },
     "localname": "DerivativeAssetsLiabilitiesAtFairValueNetByBalanceSheetClassificationAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DerivativeContractTypeDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financial instrument or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.",
        "label": "Derivative Contract [Domain]",
        "terseLabel": "Derivative Contract [Domain]"
       }
      }
     },
     "localname": "DerivativeContractTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DerivativeFairValueOfDerivativeAsset": {
     "auth_ref": [
      "r73",
      "r80",
      "r81",
      "r725",
      "r842"
     ],
     "calculation": {
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.",
        "label": "Derivative Asset, Fair Value, Gross Asset",
        "terseLabel": "Commodity Supply and Price Risk Management"
       }
      }
     },
     "localname": "DerivativeFairValueOfDerivativeAsset",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral": {
     "auth_ref": [
      "r75",
      "r76",
      "r83",
      "r734"
     ],
     "calculation": {
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value, after offset of derivative liability, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, before offset against an obligation to return collateral under a master netting arrangement. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.",
        "label": "Derivative Asset, Fair Value, Amount Not Offset Against Collateral",
        "totalLabel": "Net Amount Recorded as a Derivative"
       }
      }
     },
     "localname": "DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeFairValueOfDerivativeLiability": {
     "auth_ref": [
      "r73",
      "r80",
      "r81",
      "r725",
      "r842"
     ],
     "calculation": {
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.",
        "label": "Derivative Liability, Fair Value, Gross Liability",
        "negatedLabel": "Commodity Supply and Price Risk Management"
       }
      }
     },
     "localname": "DerivativeFairValueOfDerivativeLiability",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral": {
     "auth_ref": [
      "r75",
      "r76",
      "r83",
      "r734"
     ],
     "calculation": {
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value, after offset of derivative asset, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.",
        "label": "Derivative Liability, Fair Value, Amount Not Offset Against Collateral",
        "negatedTotalLabel": "Net Amount Recorded as a Derivative"
       }
      }
     },
     "localname": "DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeInstrumentRiskAxis": {
     "auth_ref": [
      "r80",
      "r724",
      "r726",
      "r729",
      "r732"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of derivative contract.",
        "label": "Derivative Instrument [Axis]",
        "terseLabel": "Derivative Instrument [Axis]"
       }
      }
     },
     "localname": "DerivativeInstrumentRiskAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Derivative Instruments and Hedging Activities Disclosure [Abstract]",
        "terseLabel": "Derivative Instruments and Hedging Activities Disclosure [Abstract]"
       }
      }
     },
     "localname": "DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock": {
     "auth_ref": [
      "r741",
      "r753"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for derivative instruments and hedging activities including, but not limited to, risk management strategies, non-hedging derivative instruments, assets, liabilities, revenue and expenses, and methodologies and assumptions used in determining the amounts.",
        "label": "Derivative Instruments and Hedging Activities Disclosure [Text Block]",
        "terseLabel": "DERIVATIVE INSTRUMENTS"
       }
      }
     },
     "localname": "DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTS"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Derivative Instruments and Hedging Activities Disclosures [Line Items]",
        "terseLabel": "Derivative Instruments and Hedging Activities Disclosures [Line Items]"
       }
      }
     },
     "localname": "DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSVariationsUsingSignificantunobservableInputsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about derivatives and hedging activities.",
        "label": "Derivative Instruments and Hedging Activities Disclosures [Table]",
        "terseLabel": "Derivative Instruments and Hedging Activities Disclosures [Table]"
       }
      }
     },
     "localname": "DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSVariationsUsingSignificantunobservableInputsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DerivativeLiabilitiesCurrent": {
     "auth_ref": [
      "r75"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 10.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.",
        "label": "Derivative Liability, Current",
        "terseLabel": "Derivative Liabilities"
       }
      }
     },
     "localname": "DerivativeLiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeLiabilitiesNoncurrent": {
     "auth_ref": [
      "r75"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 3.0,
       "parentTag": "us-gaap_LiabilitiesOtherThanLongtermDebtNoncurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.",
        "label": "Derivative Liability, Noncurrent",
        "terseLabel": "Derivative Liabilities"
       }
      }
     },
     "localname": "DerivativeLiabilitiesNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeLiabilityFairValueGrossAsset": {
     "auth_ref": [
      "r74",
      "r78",
      "r82",
      "r725"
     ],
     "calculation": {
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of asset associated with financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.",
        "label": "Derivative Liability, Fair Value, Gross Asset",
        "terseLabel": "Netting"
       }
      }
     },
     "localname": "DerivativeLiabilityFairValueGrossAsset",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeLiabilityFairValueNetAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Derivative Liability, Fair Value, Amount Not Offset Against Collateral [Abstract]",
        "terseLabel": "Current and Long-Term Derivative Liabilities"
       }
      }
     },
     "localname": "DerivativeLiabilityFairValueNetAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DerivativesPolicyTextBlock": {
     "auth_ref": [
      "r174",
      "r719",
      "r720",
      "r721",
      "r722",
      "r733"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy for its derivative instruments and hedging activities.",
        "label": "Derivatives, Policy [Policy Text Block]",
        "terseLabel": "Derivative Accounting"
       }
      }
     },
     "localname": "DerivativesPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DisaggregationOfRevenueLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Disaggregation of Revenue [Line Items]",
        "terseLabel": "Disaggregation of Revenue [Line Items]"
       }
      }
     },
     "localname": "DisaggregationOfRevenueLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DisaggregationOfRevenueTable": {
     "auth_ref": [
      "r500",
      "r502",
      "r503",
      "r504",
      "r505",
      "r506",
      "r507",
      "r508"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about disaggregation of revenue into categories depicting how nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factor.",
        "label": "Disaggregation of Revenue [Table]",
        "terseLabel": "Disaggregation of Revenue [Table]"
       }
      }
     },
     "localname": "DisaggregationOfRevenueTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DisaggregationOfRevenueTableTextBlock": {
     "auth_ref": [
      "r500"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of disaggregation of revenue into categories depicting how nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factor.",
        "label": "Disaggregation of Revenue [Table Text Block]",
        "terseLabel": "Schedule of Disaggregation of Revenue"
       }
      }
     },
     "localname": "DisaggregationOfRevenueTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock": {
     "auth_ref": [
      "r612",
      "r623"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of share-based payment arrangement.",
        "label": "Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]",
        "terseLabel": "Schedule of Compensation Expense and Income Tax Benefit"
       }
      }
     },
     "localname": "DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DisposalGroupClassificationAxis": {
     "auth_ref": [
      "r11"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by disposal group classification.",
        "label": "Disposal Group Classification [Axis]",
        "terseLabel": "Disposal Group Classification [Axis]"
       }
      }
     },
     "localname": "DisposalGroupClassificationAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DisposalGroupClassificationDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Component or group of components disposed of, including but not limited to, disposal group held-for-sale or disposed of by sale, disposed of by means other than sale, and discontinued operations.",
        "label": "Disposal Group Classification [Domain]",
        "terseLabel": "Disposal Group Classification [Domain]"
       }
      }
     },
     "localname": "DisposalGroupClassificationDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember": {
     "auth_ref": [
      "r350",
      "r358"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disposal group that has been sold. Excludes disposals classified as discontinued operations.",
        "label": "Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]",
        "terseLabel": "Disposal Group, Disposed of by Sale, Not Discontinued Operations"
       }
      }
     },
     "localname": "DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DisposalGroupIncludingDiscontinuedOperationGoodwill1": {
     "auth_ref": [
      "r6",
      "r7",
      "r10",
      "r356"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount classified as goodwill attributable to disposal group held for sale or disposed of.",
        "label": "Disposal Group, Including Discontinued Operation, Goodwill",
        "terseLabel": "Goodwill"
       }
      }
     },
     "localname": "DisposalGroupIncludingDiscontinuedOperationGoodwill1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment": {
     "auth_ref": [
      "r6",
      "r7",
      "r10",
      "r356"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount classified as property, plant and equipment attributable to disposal group held for sale or disposed of.",
        "label": "Disposal Group, Including Discontinued Operation, Property, Plant and Equipment",
        "terseLabel": "Property, plant and equipment, net"
       }
      }
     },
     "localname": "DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain": {
     "auth_ref": [
      "r591",
      "r604"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of disposal group.",
        "label": "Disposal Group Name [Domain]",
        "terseLabel": "Disposal Group Name [Domain]"
       }
      }
     },
     "localname": "DisposalGroupsIncludingDiscontinuedOperationsNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/GOODWILLNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DividendsCommonStock": {
     "auth_ref": [
      "r487",
      "r892"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of paid and unpaid common stock dividends declared with the form of settlement in cash, stock and payment-in-kind (PIK).",
        "label": "Dividends, Common Stock",
        "negatedTerseLabel": "Dividends on Common Stock"
       }
      }
     },
     "localname": "DividendsCommonStock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DividendsPreferredStock": {
     "auth_ref": [
      "r487",
      "r892"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of paid and unpaid preferred stock dividends declared with the form of settlement in cash, stock and payment-in-kind (PIK).",
        "label": "Dividends, Preferred Stock",
        "negatedTerseLabel": "Dividends on Preferred Stock"
       }
      }
     },
     "localname": "DividendsPreferredStock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EarningsPerShareAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Earnings Per Share [Abstract]",
        "terseLabel": "Earnings Per Share [Abstract]"
       }
      }
     },
     "localname": "EarningsPerShareAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_EarningsPerShareBasic": {
     "auth_ref": [
      "r119",
      "r194",
      "r195",
      "r197",
      "r198",
      "r199",
      "r205",
      "r208",
      "r214",
      "r215",
      "r216",
      "r220",
      "r221",
      "r751",
      "r752",
      "r881",
      "r909"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.",
        "label": "Earnings Per Share, Basic",
        "terseLabel": "Basic EPS (in dollars per share)",
        "verboseLabel": "Basic Earnings Per Common Share (in dollars per share)"
       }
      }
     },
     "localname": "EarningsPerShareBasic",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_EarningsPerShareDiluted": {
     "auth_ref": [
      "r119",
      "r194",
      "r195",
      "r197",
      "r198",
      "r199",
      "r208",
      "r214",
      "r215",
      "r216",
      "r220",
      "r221",
      "r751",
      "r752",
      "r881",
      "r909"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.",
        "label": "Earnings Per Share, Diluted",
        "terseLabel": "Diluted EPS (in dollars per share)",
        "verboseLabel": "Diluted Earnings Per Common Share (in dollars per share)"
       }
      }
     },
     "localname": "EarningsPerShareDiluted",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_EarningsPerShareTextBlock": {
     "auth_ref": [
      "r217",
      "r218",
      "r219",
      "r222"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for earnings per share.",
        "label": "Earnings Per Share [Text Block]",
        "terseLabel": "EARNINGS PER SHARE"
       }
      }
     },
     "localname": "EarningsPerShareTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EARNINGSPERSHARE"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_EffectiveIncomeTaxRateContinuingOperations": {
     "auth_ref": [
      "r640"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.",
        "label": "Effective Income Tax Rate Reconciliation, Percent",
        "terseLabel": "Effective Tax Rate"
       }
      }
     },
     "localname": "EffectiveIncomeTaxRateContinuingOperations",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized": {
     "auth_ref": [
      "r622"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cost not yet recognized for nonvested award under share-based payment arrangement.",
        "label": "Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount",
        "terseLabel": "Total unrecognized compensation expense"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1": {
     "auth_ref": [
      "r622"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
        "label": "Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition",
        "terseLabel": "Period for recognition"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense": {
     "auth_ref": [
      "r621"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of tax benefit for recognition of expense of award under share-based payment arrangement.",
        "label": "Share-based Payment Arrangement, Expense, Tax Benefit",
        "terseLabel": "Future Income Tax Benefit"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofCompensationExpenseandIncomeTaxBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EnvironmentalRemediationSiteAxis": {
     "auth_ref": [
      "r369",
      "r371",
      "r372",
      "r374",
      "r396"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by location or named area designated for environmental remediation.",
        "label": "Environmental Remediation Site [Axis]",
        "terseLabel": "Environmental Remediation Site [Axis]"
       }
      }
     },
     "localname": "EnvironmentalRemediationSiteAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EnvironmentalRemediationSiteDomain": {
     "auth_ref": [
      "r369"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Location or named area designated for environmental remediation.",
        "label": "Environmental Remediation Site [Domain]",
        "terseLabel": "Environmental Remediation Site [Domain]"
       }
      }
     },
     "localname": "EnvironmentalRemediationSiteDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Equity [Abstract]",
        "terseLabel": "Equity:"
       }
      }
     },
     "localname": "EquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EquityComponentDomain": {
     "auth_ref": [
      "r2",
      "r107",
      "r108",
      "r109",
      "r186",
      "r187",
      "r188",
      "r191",
      "r200",
      "r203",
      "r225",
      "r314",
      "r479",
      "r487",
      "r628",
      "r629",
      "r630",
      "r666",
      "r667",
      "r750",
      "r782",
      "r783",
      "r784",
      "r785",
      "r786",
      "r788",
      "r918",
      "r919",
      "r920",
      "r1011"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Components of equity are the parts of the total Equity balance including that which is allocated to common, preferred, treasury stock, retained earnings, etc.",
        "label": "Equity Component [Domain]",
        "terseLabel": "Equity Component [Domain]"
       }
      }
     },
     "localname": "EquityComponentDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails",
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails",
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity": {
     "auth_ref": [
      "r306"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Difference between amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and amount of underlying equity in net assets the reporting Entity has in the investee.",
        "label": "Equity Method Investment, Difference Between Carrying Amount and Underlying Equity",
        "terseLabel": "Carrying amount of equity method investments in excess of the underlying equity in net assets"
       }
      }
     },
     "localname": "EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EquityMethodInvestmentDividendsOrDistributions": {
     "auth_ref": [
      "r114",
      "r144",
      "r152",
      "r904"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of distribution received from equity method investee for return on investment, classified as operating activities. Excludes distribution for return of investment, classified as investing activities.",
        "label": "Proceeds from Equity Method Investment, Distribution",
        "terseLabel": "Dividends received from equity method investees"
       }
      }
     },
     "localname": "EquityMethodInvestmentDividendsOrDistributions",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment": {
     "auth_ref": [
      "r303"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the equity method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value subject to the equity accounting method. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment.",
        "label": "Equity Method Investment, Other than Temporary Impairment",
        "terseLabel": "Other-than-temporary impairment"
       }
      }
     },
     "localname": "EquityMethodInvestmentOtherThanTemporaryImpairment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EquityMethodInvestmentOwnershipPercentage": {
     "auth_ref": [
      "r305"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.",
        "label": "Equity Method Investment, Ownership Percentage",
        "terseLabel": "Ownership interest"
       }
      }
     },
     "localname": "EquityMethodInvestmentOwnershipPercentage",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails",
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails",
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESSummaryofInvestmentsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_EquityMethodInvestments": {
     "auth_ref": [
      "r45",
      "r243",
      "r304"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 3.0,
       "parentTag": "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
       "weight": 1.0
      },
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.",
        "label": "Equity Method Investments",
        "netLabel": "Investments in unconsolidated affilitates",
        "terseLabel": "Investments in Subsidiary Companies, at Equity",
        "verboseLabel": "Investments in Unconsolidated Affiliates"
       }
      }
     },
     "localname": "EquityMethodInvestments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESSummaryofInvestmentsDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EquityMethodInvestmentsAndJointVenturesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Equity Method Investments and Joint Ventures [Abstract]",
        "terseLabel": "Equity Method Investments and Joint Ventures [Abstract]"
       }
      }
     },
     "localname": "EquityMethodInvestmentsAndJointVenturesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_EquityMethodInvestmentsDisclosureTextBlock": {
     "auth_ref": [
      "r310"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for equity method investments and joint ventures. Equity method investments are investments that give the investor the ability to exercise significant influence over the operating and financial policies of an investee. Joint ventures are entities owned and operated by a small group of businesses as a separate and specific business or project for the mutual benefit of the members of the group.",
        "label": "Equity Method Investments and Joint Ventures Disclosure [Text Block]",
        "terseLabel": "INVESTMENTS IN UNCONSOLIDATED AFFILIATES"
       }
      }
     },
     "localname": "EquityMethodInvestmentsDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATES"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_EquityMethodInvestmentsTextBlock": {
     "auth_ref": [
      "r309"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of equity method investments including, but not limited to, name of each investee or group of investments, percentage ownership, difference between recorded amount of an investment and the value of the underlying equity in the net assets, and summarized financial information.",
        "label": "Equity Method Investments [Table Text Block]",
        "terseLabel": "Summary of Investments"
       }
      }
     },
     "localname": "EquityMethodInvestmentsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_EquitySecuritiesFvNi": {
     "auth_ref": [
      "r766"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current.",
        "label": "Equity Securities, FV-NI, Current",
        "terseLabel": "Equity securities"
       }
      }
     },
     "localname": "EquitySecuritiesFvNi",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESEquitySecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EquitySecuritiesFvNiUnrealizedGain": {
     "auth_ref": [
      "r302"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of unrealized gain on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).",
        "label": "Equity Securities, FV-NI, Unrealized Gain",
        "terseLabel": "Unrealized gains recorded in other income"
       }
      }
     },
     "localname": "EquitySecuritiesFvNiUnrealizedGain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESEquitySecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EstimateOfFairValueFairValueDisclosureMember": {
     "auth_ref": [
      "r438",
      "r448",
      "r449",
      "r769"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measured as an estimate of fair value.",
        "label": "Estimate of Fair Value Measurement [Member]",
        "terseLabel": "Fair Value"
       }
      }
     },
     "localname": "EstimateOfFairValueFairValueDisclosureMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ExciseAndSalesTaxes": {
     "auth_ref": [
      "r113"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of excise and sales taxes included in sales and revenues, which are then deducted as a cost of sales. Includes excise taxes, which are applied to specific types of transactions or items (such as gasoline or alcohol); and sales, use and value added taxes, which are applied to a broad class of revenue-producing transactions involving a wide range of goods and services.",
        "label": "Excise and Sales Taxes",
        "terseLabel": "Excise and sales taxes"
       }
      }
     },
     "localname": "ExciseAndSalesTaxes",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofOtherTaxesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]",
        "terseLabel": "Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable": {
     "auth_ref": [
      "r754",
      "r755",
      "r756",
      "r763"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about asset and liability measured at fair value on recurring and nonrecurring basis.",
        "label": "Fair Value, Recurring and Nonrecurring [Table]",
        "terseLabel": "Fair Value, Recurring and Nonrecurring [Table]"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock": {
     "auth_ref": [
      "r757"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of input and valuation technique used to measure fair value and change in valuation approach and technique for each separate class of asset and liability measured on recurring and nonrecurring basis.",
        "label": "Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]",
        "terseLabel": "Fair Value Inputs, Liabilities, Quantitative Information"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain": {
     "auth_ref": [
      "r759"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Class of asset.",
        "label": "Asset Class [Domain]",
        "terseLabel": "Asset Class [Domain]"
       }
      }
     },
     "localname": "FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueByAssetClassAxis": {
     "auth_ref": [
      "r754",
      "r763"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by class of asset.",
        "label": "Asset Class [Axis]",
        "terseLabel": "Asset Class [Axis]"
       }
      }
     },
     "localname": "FairValueByAssetClassAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByBalanceSheetGroupingTextBlock": {
     "auth_ref": [
      "r754",
      "r770"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the fair value of financial instruments, including financial assets and financial liabilities, and the measurements of those instruments, assets, and liabilities.",
        "label": "Fair Value, by Balance Sheet Grouping [Table Text Block]",
        "terseLabel": "Carrying Amounts and Estimated Fair Values of Financial Instruments"
       }
      }
     },
     "localname": "FairValueByBalanceSheetGroupingTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueByFairValueHierarchyLevelAxis": {
     "auth_ref": [
      "r438",
      "r448",
      "r449",
      "r542",
      "r543",
      "r544",
      "r545",
      "r546",
      "r547",
      "r548",
      "r586",
      "r755",
      "r832",
      "r833",
      "r834"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by level within fair value hierarchy and fair value measured at net asset value per share as practical expedient.",
        "label": "Fair Value Hierarchy and NAV [Axis]",
        "terseLabel": "Fair Value Hierarchy and NAV [Axis]"
       }
      }
     },
     "localname": "FairValueByFairValueHierarchyLevelAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSVariationsUsingSignificantunobservableInputsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByMeasurementBasisAxis": {
     "auth_ref": [
      "r438",
      "r448",
      "r449",
      "r754",
      "r764"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by measurement basis.",
        "label": "Measurement Basis [Axis]",
        "terseLabel": "Measurement Basis [Axis]"
       }
      }
     },
     "localname": "FairValueByMeasurementBasisAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueDisclosureItemAmountsDomain": {
     "auth_ref": [
      "r438",
      "r448",
      "r449"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measurement basis, for example, but not limited to, reported value, fair value, portion at fair value, portion at other than fair value.",
        "label": "Fair Value Measurement [Domain]",
        "terseLabel": "Fair Value Measurement [Domain]"
       }
      }
     },
     "localname": "FairValueDisclosureItemAmountsDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Fair Value Disclosures [Abstract]",
        "terseLabel": "Fair Value Disclosures [Abstract]"
       }
      }
     },
     "localname": "FairValueDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueDisclosuresTextBlock": {
     "auth_ref": [
      "r761"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.",
        "label": "Fair Value Disclosures [Text Block]",
        "terseLabel": "FAIR VALUE OF FINANCIAL INSTRUMENTS"
       }
      }
     },
     "localname": "FairValueDisclosuresTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTS"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueInputsLevel1Member": {
     "auth_ref": [
      "r438",
      "r542",
      "r543",
      "r548",
      "r586",
      "r755",
      "r832"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Quoted prices in active markets for identical assets or liabilities that the reporting entity can access at the measurement date.",
        "label": "Fair Value, Inputs, Level 1 [Member]",
        "terseLabel": "Level 1"
       }
      }
     },
     "localname": "FairValueInputsLevel1Member",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueInputsLevel2Member": {
     "auth_ref": [
      "r438",
      "r448",
      "r449",
      "r542",
      "r543",
      "r548",
      "r586",
      "r755",
      "r833"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Inputs other than quoted prices included within level 1 that are observable for an asset or liability, either directly or indirectly, including, but not limited to, quoted prices for similar assets or liabilities in active markets, or quoted prices for identical or similar assets or liabilities in inactive markets.",
        "label": "Fair Value, Inputs, Level 2 [Member]",
        "terseLabel": "Level 2"
       }
      }
     },
     "localname": "FairValueInputsLevel2Member",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueInputsLevel3Member": {
     "auth_ref": [
      "r438",
      "r448",
      "r449",
      "r542",
      "r543",
      "r544",
      "r545",
      "r546",
      "r547",
      "r548",
      "r586",
      "r755",
      "r834"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Inputs, Level 3 [Member]",
        "terseLabel": "Level 3"
       }
      }
     },
     "localname": "FairValueInputsLevel3Member",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSVariationsUsingSignificantunobservableInputsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]",
        "terseLabel": "Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]"
       }
      }
     },
     "localname": "FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSVariationsUsingSignificantunobservableInputsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements": {
     "auth_ref": [
      "r760"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements",
        "terseLabel": "Settlements"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSVariationsUsingSignificantunobservableInputsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue": {
     "auth_ref": [
      "r759"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value",
        "negatedPeriodEndLabel": "Ending balance",
        "negatedPeriodStartLabel": "Beginning balance"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSVariationsUsingSignificantunobservableInputsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueMeasurementsFairValueHierarchyDomain": {
     "auth_ref": [
      "r438",
      "r448",
      "r449",
      "r542",
      "r543",
      "r544",
      "r545",
      "r546",
      "r547",
      "r548",
      "r586",
      "r832",
      "r833",
      "r834"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Categories used to prioritize the inputs to valuation techniques to measure fair value.",
        "label": "Fair Value Hierarchy and NAV [Domain]",
        "terseLabel": "Fair Value Hierarchy and NAV [Domain]"
       }
      }
     },
     "localname": "FairValueMeasurementsFairValueHierarchyDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSDerivativeContractsatFairValueDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSVariationsUsingSignificantunobservableInputsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTableTextBlock": {
     "auth_ref": [
      "r759",
      "r762"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset) using recurring unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]",
        "terseLabel": "Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation"
       }
      }
     },
     "localname": "FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueOfFinancialInstrumentsPolicy": {
     "auth_ref": [
      "r765",
      "r768"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy for determining the fair value of financial instruments.",
        "label": "Fair Value of Financial Instruments, Policy [Policy Text Block]",
        "verboseLabel": "Fair Value Measurements"
       }
      }
     },
     "localname": "FairValueOfFinancialInstrumentsPolicy",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FinanceLeaseInterestExpense": {
     "auth_ref": [
      "r800",
      "r805",
      "r814"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails": {
       "order": 2.0,
       "parentTag": "es_FinanceLeaseCost",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest expense on finance lease liability.",
        "label": "Finance Lease, Interest Expense",
        "terseLabel": "Interest on Lease Liabilities"
       }
      }
     },
     "localname": "FinanceLeaseInterestExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseInterestPaymentOnLiability": {
     "auth_ref": [
      "r802",
      "r808"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest paid on finance lease liability.",
        "label": "Finance Lease, Interest Payment on Liability",
        "terseLabel": "Operating Cash Flows from Finance Leases"
       }
      }
     },
     "localname": "FinanceLeaseInterestPaymentOnLiability",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Finance Lease, Liability, Payment, Due [Abstract]",
        "terseLabel": "Finance Leases"
       }
      }
     },
     "localname": "FinanceLeaseLiabilitiesPaymentsDueAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinanceLeaseLiability": {
     "auth_ref": [
      "r798",
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_FinanceLeaseLiabilityPaymentsDue",
       "weight": 1.0
      },
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Present value of lessee's discounted obligation for lease payments from finance lease.",
        "label": "Finance Lease, Liability",
        "terseLabel": "Present value of future minimum lease payments",
        "totalLabel": "Total Finance Lease Liabilities"
       }
      }
     },
     "localname": "FinanceLeaseLiability",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails",
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseLiabilityCurrent": {
     "auth_ref": [
      "r798"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_FinanceLeaseLiability",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Present value of lessee's discounted obligation for lease payments from finance lease, classified as current.",
        "label": "Finance Lease, Liability, Current",
        "terseLabel": "Current Portion"
       }
      }
     },
     "localname": "FinanceLeaseLiabilityCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList": {
     "auth_ref": [
      "r799"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates line item in statement of financial position that includes current finance lease liability.",
        "label": "Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]",
        "terseLabel": "Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]"
       }
      }
     },
     "localname": "FinanceLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "enumerationSetItemType"
    },
    "us-gaap_FinanceLeaseLiabilityMaturityTableTextBlock": {
     "auth_ref": [
      "r813"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of undiscounted cash flows of finance lease liability. Includes, but is not limited to, reconciliation of undiscounted cash flows to finance lease liability recognized in statement of financial position.",
        "label": "Finance Lease, Liability, Fiscal Year Maturity [Table Text Block]",
        "terseLabel": "Future Minimum Lease Payments under Long-Term Finance Leases"
       }
      }
     },
     "localname": "FinanceLeaseLiabilityMaturityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FinanceLeaseLiabilityNoncurrent": {
     "auth_ref": [
      "r798"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_FinanceLeaseLiability",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Present value of lessee's discounted obligation for lease payments from finance lease, classified as noncurrent.",
        "label": "Finance Lease, Liability, Noncurrent",
        "terseLabel": "Long-Term"
       }
      }
     },
     "localname": "FinanceLeaseLiabilityNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList": {
     "auth_ref": [
      "r799"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates line item in statement of financial position that includes noncurrent finance lease liability.",
        "label": "Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]",
        "terseLabel": "Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]"
       }
      }
     },
     "localname": "FinanceLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "enumerationSetItemType"
    },
    "us-gaap_FinanceLeaseLiabilityPaymentsDue": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails_1": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payments for finance lease.",
        "label": "Finance Lease, Liability, Payment, Due",
        "totalLabel": "Future lease payments"
       }
      }
     },
     "localname": "FinanceLeaseLiabilityPaymentsDue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails_1": {
       "order": 6.0,
       "parentTag": "us-gaap_FinanceLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Finance Lease, Liability, to be Paid, after Year Five",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "FinanceLeaseLiabilityPaymentsDueAfterYearFive",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails_1": {
       "order": 1.0,
       "parentTag": "us-gaap_FinanceLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Finance Lease, Liability, to be Paid, Year One",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "FinanceLeaseLiabilityPaymentsDueNextTwelveMonths",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails_1": {
       "order": 5.0,
       "parentTag": "us-gaap_FinanceLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Finance Lease, Liability, to be Paid, Year Five",
        "terseLabel": "2026"
       }
      }
     },
     "localname": "FinanceLeaseLiabilityPaymentsDueYearFive",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails_1": {
       "order": 4.0,
       "parentTag": "us-gaap_FinanceLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Finance Lease, Liability, to be Paid, Year Four",
        "terseLabel": "2025"
       }
      }
     },
     "localname": "FinanceLeaseLiabilityPaymentsDueYearFour",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails_1": {
       "order": 3.0,
       "parentTag": "us-gaap_FinanceLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Finance Lease, Liability, to be Paid, Year Three",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "FinanceLeaseLiabilityPaymentsDueYearThree",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails_1": {
       "order": 2.0,
       "parentTag": "us-gaap_FinanceLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Finance Lease, Liability, to be Paid, Year Two",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "FinanceLeaseLiabilityPaymentsDueYearTwo",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_FinanceLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for finance lease.",
        "label": "Finance Lease, Liability, Undiscounted Excess Amount",
        "terseLabel": "Less amount representing interest"
       }
      }
     },
     "localname": "FinanceLeaseLiabilityUndiscountedExcessAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeasePrincipalPayments": {
     "auth_ref": [
      "r801",
      "r808"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow for principal payment on finance lease.",
        "label": "Finance Lease, Principal Payments",
        "terseLabel": "Financing Cash Flows from Finance Leases"
       }
      }
     },
     "localname": "FinanceLeasePrincipalPayments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseRightOfUseAsset": {
     "auth_ref": [
      "r797"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after accumulated amortization, of right-of-use asset from finance lease.",
        "label": "Finance Lease, Right-of-Use Asset, after Accumulated Amortization",
        "terseLabel": "Right-of-use-Assets, Net"
       }
      }
     },
     "localname": "FinanceLeaseRightOfUseAsset",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseRightOfUseAssetAmortization": {
     "auth_ref": [
      "r800",
      "r805",
      "r814"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails": {
       "order": 1.0,
       "parentTag": "es_FinanceLeaseCost",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of amortization expense attributable to right-of-use asset from finance lease.",
        "label": "Finance Lease, Right-of-Use Asset, Amortization",
        "terseLabel": "Amortization of Right-of-use-Assets"
       }
      }
     },
     "localname": "FinanceLeaseRightOfUseAssetAmortization",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinanceLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList": {
     "auth_ref": [
      "r799"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates line item in statement of financial position that includes finance lease right-of-use asset.",
        "label": "Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]",
        "terseLabel": "Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]"
       }
      }
     },
     "localname": "FinanceLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "enumerationSetItemType"
    },
    "us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent": {
     "auth_ref": [
      "r811",
      "r814"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average discount rate for finance lease calculated at point in time.",
        "label": "Finance Lease, Weighted Average Discount Rate, Percent",
        "terseLabel": "Finance Leases"
       }
      }
     },
     "localname": "FinanceLeaseWeightedAverageDiscountRatePercent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1": {
     "auth_ref": [
      "r810",
      "r814"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average remaining lease term for finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
        "label": "Finance Lease, Weighted Average Remaining Lease Term",
        "terseLabel": "Finance Leases"
       }
      }
     },
     "localname": "FinanceLeaseWeightedAverageRemainingLeaseTerm1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_FinancialInstrumentAxis": {
     "auth_ref": [
      "r291",
      "r292",
      "r299",
      "r300",
      "r301",
      "r318",
      "r324",
      "r325",
      "r326",
      "r327",
      "r330",
      "r331",
      "r332",
      "r333",
      "r446",
      "r477",
      "r741",
      "r829",
      "r830",
      "r831",
      "r832",
      "r833",
      "r834",
      "r835",
      "r836",
      "r837",
      "r838",
      "r839",
      "r840",
      "r841",
      "r843",
      "r844",
      "r845",
      "r846",
      "r847",
      "r848",
      "r849",
      "r850",
      "r851",
      "r852",
      "r853",
      "r854",
      "r855",
      "r856",
      "r857",
      "r858",
      "r859",
      "r971",
      "r972",
      "r973",
      "r974",
      "r975",
      "r976",
      "r977"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of financial instrument.",
        "label": "Financial Instrument [Axis]",
        "terseLabel": "Financial Instrument [Axis]"
       }
      }
     },
     "localname": "FinancialInstrumentAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Financing Receivable, Allowance for Credit Loss [Roll Forward]",
        "terseLabel": "Financing Receivable, Allowance for Credit Loss [Roll Forward]"
       }
      }
     },
     "localname": "FinancingReceivableAllowanceForCreditLossesRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FirstMortgageMember": {
     "auth_ref": [
      "r932"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loan secured by real property that has a first (highest) lien on such property in the event of default by the borrower.",
        "label": "First Mortgage [Member]",
        "terseLabel": "PSNH 4.050% Series Q First Mortgage Bond",
        "verboseLabel": "First Mortgage Bonds"
       }
      }
     },
     "localname": "FirstMortgageMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FixedIncomeFundsMember": {
     "auth_ref": [
      "r542"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Investment that pools funds from investors to invest in a combination of underlying investments, primarily fixed income investments.",
        "label": "Fixed Income Funds [Member]",
        "terseLabel": "Fixed Income"
       }
      }
     },
     "localname": "FixedIncomeFundsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FixedIncomeSecuritiesMember": {
     "auth_ref": [
      "r542",
      "r586"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Investment that provides a return in the form of fixed periodic payments and eventual return of principal at maturity.",
        "label": "Fixed Income Securities [Member]",
        "terseLabel": "Fixed Income"
       }
      }
     },
     "localname": "FixedIncomeSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ForwardContractIndexedToIssuersEquityForwardRate": {
     "auth_ref": [
      "r453",
      "r739"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The per share price of the Company's stock at which the contract holder of the freestanding contract has the right to purchase or sell the Company's stock at a future date.",
        "label": "Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share",
        "terseLabel": "Forward sale price (in dollars per share)"
       }
      }
     },
     "localname": "ForwardContractIndexedToIssuersEquityForwardRate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ForwardContractIndexedToIssuersEquityShares": {
     "auth_ref": [
      "r740"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The maximum number of shares that could be issued to net share settle a contract, if applicable. If a contract does not have a fixed or determinable maximum number of shares that may be required to be issued, disclose the fact that a potentially infinite number of shares could be issued to settle the contract.",
        "label": "Forward Contract Indexed to Issuer's Equity, Shares",
        "terseLabel": "Common shares issuable pursuant to forward sale agreement (in shares)"
       }
      }
     },
     "localname": "ForwardContractIndexedToIssuersEquityShares",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_GainLossOnSaleOfPropertyPlantEquipment": {
     "auth_ref": [
      "r152"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of gain (loss) on sale or disposal of property, plant and equipment assets, including oil and gas property and timber property.",
        "label": "Gain (Loss) on Disposition of Property Plant Equipment",
        "terseLabel": "Pre-tax gain (loss) on sale of property, plant and equipment"
       }
      }
     },
     "localname": "GainLossOnSaleOfPropertyPlantEquipment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GainLossRelatedToLitigationSettlement": {
     "auth_ref": [
      "r384"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 19.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of gain (loss) recognized in settlement of litigation and insurance claims. Excludes claims within an insurance entity's normal claims settlement process.",
        "label": "Gain (Loss) Related to Litigation Settlement",
        "negatedLabel": "Loss related to litigation settlement",
        "negatedTerseLabel": "Reserve at CL&amp;P related to PURA Settlement Agreement and Storm Performance Penalty"
       }
      }
     },
     "localname": "GainLossRelatedToLitigationSettlement",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/REVENUESNarrativeDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_Goodwill": {
     "auth_ref": [
      "r339",
      "r341",
      "r826",
      "r866"
     ],
     "calculation": {
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet",
       "weight": 1.0
      },
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 2.0,
       "parentTag": "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
       "weight": 1.0
      },
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.",
        "label": "Goodwill",
        "periodEndLabel": "Balance",
        "periodStartLabel": "Balance",
        "terseLabel": "Goodwill"
       }
      }
     },
     "localname": "Goodwill",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails",
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/GOODWILLSummaryofGoodwillbyReportableSegmentDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GoodwillAcquiredDuringPeriod": {
     "auth_ref": [
      "r342"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.",
        "label": "Goodwill, Acquired During Period",
        "verboseLabel": "Goodwill acquired"
       }
      }
     },
     "localname": "GoodwillAcquiredDuringPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/GOODWILLNarrativeDetails",
      "http://www.eversource.com/role/GOODWILLSummaryofGoodwillbyReportableSegmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Goodwill and Intangible Assets Disclosure [Abstract]"
       }
      }
     },
     "localname": "GoodwillAndIntangibleAssetsDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_GoodwillDisclosureTextBlock": {
     "auth_ref": [
      "r349"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for goodwill.",
        "label": "Goodwill Disclosure [Text Block]",
        "terseLabel": "Goodwill"
       }
      }
     },
     "localname": "GoodwillDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/GOODWILL"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_GoodwillImpairmentLoss": {
     "auth_ref": [
      "r152",
      "r340",
      "r344",
      "r347"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.",
        "label": "Goodwill, Impairment Loss",
        "terseLabel": "Impairment loss"
       }
      }
     },
     "localname": "GoodwillImpairmentLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails",
      "http://www.eversource.com/role/GOODWILLNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GoodwillLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Goodwill [Line Items]",
        "terseLabel": "Goodwill [Line Items]"
       }
      }
     },
     "localname": "GoodwillLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/GOODWILLNarrativeDetails",
      "http://www.eversource.com/role/GOODWILLSummaryofGoodwillbyReportableSegmentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_GoodwillPurchaseAccountingAdjustments": {
     "auth_ref": [
      "r345",
      "r679"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.",
        "label": "Goodwill, Purchase Accounting Adjustments",
        "terseLabel": "Goodwill measurement period adjustments"
       }
      }
     },
     "localname": "GoodwillPurchaseAccountingAdjustments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/GOODWILLNarrativeDetails",
      "http://www.eversource.com/role/GOODWILLSummaryofGoodwillbyReportableSegmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GoodwillRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Goodwill [Roll Forward]",
        "terseLabel": "Goodwill [Roll Forward]"
       }
      }
     },
     "localname": "GoodwillRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/GOODWILLSummaryofGoodwillbyReportableSegmentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit": {
     "auth_ref": [
      "r343"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.",
        "label": "Goodwill, Written off Related to Sale of Business Unit",
        "negatedTerseLabel": "Sale of Hingham water system",
        "terseLabel": "Goodwill disposed of"
       }
      }
     },
     "localname": "GoodwillWrittenOffRelatedToSaleOfBusinessUnit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/GOODWILLNarrativeDetails",
      "http://www.eversource.com/role/GOODWILLSummaryofGoodwillbyReportableSegmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GuaranteeObligationsByNatureAxis": {
     "auth_ref": [
      "r406"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by nature of guarantee.",
        "label": "Guarantor Obligations, Nature [Axis]",
        "terseLabel": "Guarantor Obligations, Nature [Axis]"
       }
      }
     },
     "localname": "GuaranteeObligationsByNatureAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_GuaranteeObligationsCurrentCarryingValue": {
     "auth_ref": [
      "r405"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.",
        "label": "Guarantor Obligations, Current Carrying Value",
        "terseLabel": "Fair value of guarantees"
       }
      }
     },
     "localname": "GuaranteeObligationsCurrentCarryingValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESGuaranteesandObligationsNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GuaranteeObligationsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Guarantor Obligations [Line Items]",
        "terseLabel": "Guarantor Obligations [Line Items]"
       }
      }
     },
     "localname": "GuaranteeObligationsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_GuaranteeObligationsMaximumExposure": {
     "auth_ref": [
      "r404"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.",
        "label": "Guarantor Obligations, Maximum Exposure, Undiscounted",
        "verboseLabel": "Maximum Exposure"
       }
      }
     },
     "localname": "GuaranteeObligationsMaximumExposure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GuaranteeObligationsNatureDomain": {
     "auth_ref": [
      "r403"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents a description of the nature of the guarantee or each group of similar guarantees.",
        "label": "Guarantor Obligations, Nature [Domain]",
        "terseLabel": "Guarantor Obligations, Nature [Domain]"
       }
      }
     },
     "localname": "GuaranteeObligationsNatureDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic": {
     "auth_ref": [
      "r168",
      "r673"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 1.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.",
        "label": "Income (Loss) from Continuing Operations before Income Taxes, Domestic",
        "terseLabel": "Income Before Income Tax Expense",
        "totalLabel": "Income Before Income Tax Expense"
       }
      }
     },
     "localname": "IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeLossFromEquityMethodInvestments": {
     "auth_ref": [
      "r114",
      "r152",
      "r239",
      "r304",
      "r876",
      "r904"
     ],
     "calculation": {
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of income (loss) for proportionate share of equity method investee's income (loss).",
        "label": "Income (Loss) from Equity Method Investments",
        "negatedLabel": "Equity in Earnings of Subsidiaries",
        "netLabel": "Equity in earnings of unconsolidated affiliates, net of impairment",
        "terseLabel": "Equity in Earnings of Subsidiaries",
        "verboseLabel": "Unrealized gain associated with investment"
       }
      }
     },
     "localname": "IncomeLossFromEquityMethodInvestments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeStatementAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Income Statement [Abstract]",
        "terseLabel": "Income Statement [Abstract]"
       }
      }
     },
     "localname": "IncomeStatementAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis": {
     "auth_ref": [
      "r591",
      "r604"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by name of disposal group.",
        "label": "Disposal Group Name [Axis]",
        "terseLabel": "Disposal Group Name [Axis]"
       }
      }
     },
     "localname": "IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/GOODWILLNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementLocationAxis": {
     "auth_ref": [
      "r355",
      "r375"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by location in the income statement.",
        "label": "Income Statement Location [Axis]",
        "terseLabel": "Income Statement Location [Axis]"
       }
      }
     },
     "localname": "IncomeStatementLocationAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/REVENUESNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementLocationDomain": {
     "auth_ref": [
      "r375"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Location in the income statement.",
        "label": "Income Statement Location [Domain]",
        "terseLabel": "Income Statement Location [Domain]"
       }
      }
     },
     "localname": "IncomeStatementLocationDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/REVENUESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_IncomeTaxAuthorityAxis": {
     "auth_ref": [
      "r644"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by tax jurisdiction.",
        "label": "Income Tax Authority [Axis]",
        "terseLabel": "Income Tax Authority [Axis]"
       }
      }
     },
     "localname": "IncomeTaxAuthorityAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails",
      "http://www.eversource.com/role/INCOMETAXESTaxCreditsandLossCarryforwardsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxAuthorityDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Agency, division or body classification that levies income taxes, examines tax returns for compliance, or grants exemptions from or makes other decisions pertaining to income taxes.",
        "label": "Income Tax Authority [Domain]",
        "terseLabel": "Income Tax Authority [Domain]"
       }
      }
     },
     "localname": "IncomeTaxAuthorityDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails",
      "http://www.eversource.com/role/INCOMETAXESTaxCreditsandLossCarryforwardsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_IncomeTaxContingencyLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Income Tax Contingency [Line Items]",
        "terseLabel": "Income Tax Contingency [Line Items]"
       }
      }
     },
     "localname": "IncomeTaxContingencyLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationofUnrecognizedTaxBenefitDetails",
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxContingencyTable": {
     "auth_ref": [
      "r645",
      "r650",
      "r652",
      "r665"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about tax positions taken in the tax returns filed or to be filed for which it is more likely than not that the tax position will not be sustained upon examination by taxing authorities and other income tax contingencies. Includes, but is not limited to, interest and penalties, reconciliation of unrecognized tax benefits, unrecognized tax benefits that would affect the effective tax rate, tax years that remain subject to examination by tax jurisdictions, and information about positions for which it is reasonably possible that amounts unrecognized will significantly change within 12 months.",
        "label": "Income Tax Contingency [Table]",
        "terseLabel": "Income Tax Contingency [Table]"
       }
      }
     },
     "localname": "IncomeTaxContingencyTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationofUnrecognizedTaxBenefitDetails",
      "http://www.eversource.com/role/INCOMETAXESTemporaryDifferencesThatGiveRiseToAccumulatedDeferredIncomeTaxObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Income Tax Disclosure [Abstract]",
        "terseLabel": "Income Tax Disclosure [Abstract]"
       }
      }
     },
     "localname": "IncomeTaxDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxDisclosureTextBlock": {
     "auth_ref": [
      "r169",
      "r641",
      "r651",
      "r657",
      "r668",
      "r674",
      "r676",
      "r677",
      "r678"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.",
        "label": "Income Tax Disclosure [Text Block]",
        "terseLabel": "INCOME TAXES"
       }
      }
     },
     "localname": "IncomeTaxDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXES"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued": {
     "auth_ref": [
      "r642"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of estimated penalties and interest accrued as of the balance sheet date arising from income tax examinations.",
        "label": "Income Tax Examination, Penalties and Interest Accrued",
        "terseLabel": "Accrued interest payable"
       }
      }
     },
     "localname": "IncomeTaxExaminationPenaltiesAndInterestAccrued",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r170",
      "r202",
      "r203",
      "r240",
      "r639",
      "r669",
      "r675",
      "r910"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 2.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "weight": -1.0
      },
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.",
        "label": "Income Tax Expense (Benefit)",
        "negatedLabel": "Income Tax (Expense)/Benefit",
        "negatedTerseLabel": "Tax Effect",
        "terseLabel": "Income Tax Expense",
        "totalLabel": "Income Tax Expense",
        "verboseLabel": "Income Tax Benefit"
       }
      }
     },
     "localname": "IncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxPolicyTextBlock": {
     "auth_ref": [
      "r106",
      "r635",
      "r636",
      "r651",
      "r652",
      "r656",
      "r664"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.",
        "label": "Income Tax, Policy [Policy Text Block]",
        "terseLabel": "Other Taxes"
       }
      }
     },
     "localname": "IncomeTaxPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_IncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends": {
     "auth_ref": [
      "r640"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails": {
       "order": 9.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to deduction for dividend paid to employee stock ownership plan.",
        "label": "Effective Income Tax Rate Reconciliation, Deduction, Employee Stock Ownership Plan Dividend, Amount",
        "negatedTerseLabel": "Dividends on ESOP"
       }
      }
     },
     "localname": "IncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance": {
     "auth_ref": [
      "r640"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.",
        "label": "Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount",
        "terseLabel": "Tax Asset Valuation \u00a0\u00a0Allowance/Reserve Adjustments"
       }
      }
     },
     "localname": "IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate": {
     "auth_ref": [
      "r640"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.",
        "label": "Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount",
        "terseLabel": "Statutory Federal Income Tax Expense at 21%"
       }
      }
     },
     "localname": "IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationNondeductibleExpenseAmortization": {
     "auth_ref": [
      "r640"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails": {
       "order": 8.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to nondeductible amortization.",
        "label": "Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization, Amount",
        "terseLabel": "EDIT Amortization"
       }
      }
     },
     "localname": "IncomeTaxReconciliationNondeductibleExpenseAmortization",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationNondeductibleExpenseDepreciation": {
     "auth_ref": [
      "r640"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to nondeductible depreciation.",
        "label": "Effective Income Tax Rate Reconciliation, Nondeductible Expense, Depreciation, Amount",
        "terseLabel": "Depreciation"
       }
      }
     },
     "localname": "IncomeTaxReconciliationNondeductibleExpenseDepreciation",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationNondeductibleExpenseDepreciationAndAmortizationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Effective Income Tax Rate Reconciliation, Nondeductible Expense, Depreciation and Amortization, Amount [Abstract]",
        "terseLabel": "Tax Effect of Differences:"
       }
      }
     },
     "localname": "IncomeTaxReconciliationNondeductibleExpenseDepreciationAndAmortizationAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxReconciliationOtherAdjustments": {
     "auth_ref": [
      "r640"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other adjustments.",
        "label": "Effective Income Tax Rate Reconciliation, Other Adjustments, Amount",
        "terseLabel": "Other, Net"
       }
      }
     },
     "localname": "IncomeTaxReconciliationOtherAdjustments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes": {
     "auth_ref": [
      "r640"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to state and local income tax expense (benefit).",
        "label": "Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount",
        "terseLabel": "State Income Taxes, Net of Federal Impact"
       }
      }
     },
     "localname": "IncomeTaxReconciliationStateAndLocalIncomeTaxes",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationTaxCreditsInvestment": {
     "auth_ref": [
      "r640"
     ],
     "calculation": {
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": -1.0
      },
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to investment tax credit.",
        "label": "Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Amount",
        "negatedLabel": "Investment Tax Credits, Net",
        "negatedTerseLabel": "Investment Tax Credit Amortization"
       }
      }
     },
     "localname": "IncomeTaxReconciliationTaxCreditsInvestment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESComponentsofIncomeTaxExpenseDetails",
      "http://www.eversource.com/role/INCOMETAXESReconciliationBetweenIncomeTaxExpenseandExpectedTaxExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxesPaidNet": {
     "auth_ref": [
      "r156"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes.",
        "label": "Income Taxes Paid, Net",
        "terseLabel": "Income Taxes",
        "verboseLabel": "Income Taxes"
       }
      }
     },
     "localname": "IncomeTaxesPaidNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSupplementalCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxesPaidNetAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Income Taxes Paid, Net [Abstract]",
        "terseLabel": "Cash Paid During the Year for:"
       }
      }
     },
     "localname": "IncomeTaxesPaidNetAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSupplementalCashFlowInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxesReceivable": {
     "auth_ref": [
      "r65",
      "r873",
      "r903"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 8.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Carrying amount due within one year of the balance sheet date (or one operating cycle, if longer) from tax authorities as of the balance sheet date representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes.",
        "label": "Income Taxes Receivable, Current",
        "terseLabel": "Taxes Receivable"
       }
      }
     },
     "localname": "IncomeTaxesReceivable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseDueFromAffiliates": {
     "auth_ref": [
      "r151"
     ],
     "calculation": {
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in receivables to be collected from an entity that is controlling, under the control of, or within the same control group as the reporting entity by means of direct or indirect ownership.",
        "label": "Increase (Decrease) Due from Affiliates",
        "negatedTerseLabel": "Increase in Notes Receivable from Subsidiaries"
       }
      }
     },
     "localname": "IncreaseDecreaseDueFromAffiliates",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables": {
     "auth_ref": [
      "r151"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 13.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      },
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in the amount due from customers for the credit sale of goods and services; includes accounts receivable and other types of receivables.",
        "label": "Increase (Decrease) in Accounts and Other Receivables",
        "negatedLabel": "Receivables and Unbilled Revenues, Net",
        "negatedTerseLabel": "Accounts Receivables from Subsidiaries"
       }
      }
     },
     "localname": "IncreaseDecreaseInAccountsAndOtherReceivables",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInAccountsPayable": {
     "auth_ref": [
      "r151"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 16.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in the aggregate amount of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business.",
        "label": "Increase (Decrease) in Accounts Payable",
        "negatedLabel": "Increase to operating cash inflows in accounts payable",
        "terseLabel": "Accounts Payable"
       }
      }
     },
     "localname": "IncreaseDecreaseInAccountsPayable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInAccountsPayableRelatedParties": {
     "auth_ref": [
      "r151"
     ],
     "calculation": {
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": 9.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in the obligations due for goods and services provided by the following types of related parties: a parent company and its subsidiaries, subsidiaries of a common parent, an entity and trust for the benefit of employees, such as pension and profit-sharing trusts that are managed by or under the trusteeship of the entities' management, an entity and its principal owners, management, or member of their immediate families, affiliates, or other parties with the ability to exert significant influence.",
        "label": "Increase (Decrease) in Accounts Payable, Related Parties",
        "verboseLabel": "Accounts Payable to Subsidiaries"
       }
      }
     },
     "localname": "IncreaseDecreaseInAccountsPayableRelatedParties",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInDueToRelatedParties": {
     "auth_ref": [
      "r151"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 11.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in the aggregate amount of obligations to be paid to the following types of related parties: a parent company and its subsidiaries; subsidiaries of a common parent; an entity and trust for the benefit of employees, such as pension and profit-sharing trusts that are managed by or under the trusteeship of the entities' management; an entity and its principal owners, management, or member of their immediate families; affiliates; or other parties with the ability to exert significant influence.",
        "label": "Increase (Decrease) in Due to Related Parties",
        "terseLabel": "Increase/(Decrease) in Notes Payable to Eversource Parent",
        "verboseLabel": "(Decrease)/Increase in Notes Payable to Eversource Parent"
       }
      }
     },
     "localname": "IncreaseDecreaseInDueToRelatedParties",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInIncomeTaxesReceivable": {
     "auth_ref": [
      "r151"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 15.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      },
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": 7.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in income taxes receivable, which represents the amount due from tax authorities for refunds of overpayments or recoveries of income taxes paid.",
        "label": "Increase (Decrease) in Income Taxes Receivable",
        "negatedLabel": "Taxes Receivable/Accrued, Net",
        "negatedTerseLabel": "Taxes Receivable/Accrued, Net"
       }
      }
     },
     "localname": "IncreaseDecreaseInIncomeTaxesReceivable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInInventories": {
     "auth_ref": [
      "r151"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 14.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in the aggregate value of all inventory held by the reporting entity, associated with underlying transactions that are classified as operating activities.",
        "label": "Increase (Decrease) in Inventories",
        "negatedLabel": "Fuel, Materials, Supplies and REC Inventory",
        "negatedTerseLabel": "Materials, Supplies and REC Inventory"
       }
      }
     },
     "localname": "IncreaseDecreaseInInventories",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInOperatingCapitalAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Increase (Decrease) in Operating Capital [Abstract]",
        "terseLabel": "Changes in Current Assets and Liabilities:"
       }
      }
     },
     "localname": "IncreaseDecreaseInOperatingCapitalAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet": {
     "auth_ref": [
      "r151"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 17.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      },
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in operating assets after deduction of operating liabilities classified as other.",
        "label": "Increase (Decrease) in Other Operating Assets and Liabilities, Net",
        "negatedLabel": "Other Current Assets and Liabilities, Net",
        "negatedTerseLabel": "Other Current Assets and Liabilities, Net"
       }
      }
     },
     "localname": "IncreaseDecreaseInOtherOperatingCapitalNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInRegulatoryAssetsAndLiabilities": {
     "auth_ref": [
      "r151"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 7.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in the value of assets that are created when regulatory agencies permits public utilities to defer costs (revenues) to the balance sheet. This element is a the increase (decrease) of regulatory assets and liabilities combined.",
        "label": "Increase (Decrease) in Regulatory Assets and Liabilities",
        "negatedLabel": "Regulatory Underrecoveries, Net",
        "negatedTerseLabel": "Regulatory Over/(Underrecoveries), Net"
       }
      }
     },
     "localname": "IncreaseDecreaseInRegulatoryAssetsAndLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInStockholdersEquityRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Increase (Decrease) in Stockholders' Equity [Roll Forward]",
        "terseLabel": "Increase (Decrease) in Stockholders' Equity [Roll Forward]"
       }
      }
     },
     "localname": "IncreaseDecreaseInStockholdersEquityRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncrementalCommonSharesAttributableToEquityForwardAgreements": {
     "auth_ref": [
      "r210",
      "r216"
     ],
     "calculation": {
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment",
       "weight": 1.0
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Additional shared included in the calculation of diluted EPS as a result of the potentially dilutive effect of equity forward arrangements using the reverse treasury stock method.",
        "label": "Incremental Common Shares Attributable to Dilutive Effect of Equity Forward Agreements",
        "terseLabel": "Equity Forward Sale Agreement (in shares)"
       }
      }
     },
     "localname": "IncrementalCommonSharesAttributableToEquityForwardAgreements",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_IndemnificationGuaranteeMember": {
     "auth_ref": [
      "r400",
      "r408"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "An agreement (contract) that contingently requires the guarantor to make payments to the guaranteed party in compensation for that party's or parties' loss or injury attributable to specified events or actions, such as a patent infringement action against an entity that relied on certain representations as to ownership rights made by a software vendor.",
        "label": "Indemnification Agreement [Member]",
        "terseLabel": "Funding and Indemnification Obligations"
       }
      }
     },
     "localname": "IndemnificationGuaranteeMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InterestExpense": {
     "auth_ref": [
      "r111",
      "r236",
      "r790",
      "r793",
      "r882"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 2.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic",
       "weight": -1.0
      },
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the cost of borrowed funds accounted for as interest expense.",
        "label": "Interest Expense",
        "negatedTerseLabel": "Interest Expense",
        "terseLabel": "Interest Expense",
        "verboseLabel": "Interest Expense on RRB Principal (included in Interest Expense)"
       }
      }
     },
     "localname": "InterestExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESIncomeStatementDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestIncomeExpenseNonoperatingNet": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The net amount of nonoperating interest income (expense).",
        "label": "Interest Income (Expense), Nonoperating, Net",
        "terseLabel": "Qualified Cash Flow Hedging Instruments"
       }
      }
     },
     "localname": "InterestIncomeExpenseNonoperatingNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestIncomeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Primary financial statement caption in which reported facts about interest income have been included.",
        "label": "Interest Income [Member]",
        "terseLabel": "Interest Income"
       }
      }
     },
     "localname": "InterestIncomeMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InterestPaidNet": {
     "auth_ref": [
      "r141",
      "r148",
      "r156"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash paid for interest, excluding capitalized interest, classified as operating activity. Includes, but is not limited to, payment to settle zero-coupon bond for accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount.",
        "label": "Interest Paid, Excluding Capitalized Interest, Operating Activities",
        "terseLabel": "Interest, Net of Amounts Capitalized",
        "verboseLabel": "Interest"
       }
      }
     },
     "localname": "InterestPaidNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSupplementalCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestRateContractMember": {
     "auth_ref": [
      "r80",
      "r542",
      "r730"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Derivative instrument whose primary underlying risk is tied to the right to receive or pay a sum of money at a given interest rate.",
        "label": "Interest Rate Contract [Member]",
        "terseLabel": "Interest Expense"
       }
      }
     },
     "localname": "InterestRateContractMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_IntersegmentEliminationMember": {
     "auth_ref": [
      "r234",
      "r247",
      "r248",
      "r249",
      "r250",
      "r252",
      "r254",
      "r258"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Eliminating entries used in operating segment consolidation.",
        "label": "Intersegment Eliminations [Member]",
        "terseLabel": "Eliminations",
        "verboseLabel": "Eliminations"
       }
      }
     },
     "localname": "IntersegmentEliminationMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InventoryGross": {
     "auth_ref": [
      "r69"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Gross amount, as of the balance sheet date, of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.",
        "label": "Inventory, Gross",
        "terseLabel": "Total"
       }
      }
     },
     "localname": "InventoryGross",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InventoryPolicyTextBlock": {
     "auth_ref": [
      "r22",
      "r70",
      "r162",
      "r223",
      "r334",
      "r335",
      "r336",
      "r861"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of inventory accounting policy for inventory classes, including, but not limited to, basis for determining inventory amounts, methods by which amounts are added and removed from inventory classes, loss recognition on impairment of inventories, and situations in which inventories are stated above cost.",
        "label": "Inventory, Policy [Policy Text Block]",
        "terseLabel": "Fuel, Materials, Supplies and REC Inventory"
       }
      }
     },
     "localname": "InventoryPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_InventoryRawMaterialsAndSupplies": {
     "auth_ref": [
      "r68"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 4.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Gross amount of unprocessed materials to be used in manufacturing or production process and supplies that will be consumed.",
        "label": "Inventory, Raw Materials and Supplies, Gross",
        "terseLabel": "Fuel, Materials, Supplies and REC Inventory"
       }
      }
     },
     "localname": "InventoryRawMaterialsAndSupplies",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InvestmentIncomeInterest": {
     "auth_ref": [
      "r124",
      "r235"
     ],
     "calculation": {
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.",
        "label": "Investment Income, Interest",
        "terseLabel": "Interest Income"
       }
      }
     },
     "localname": "InvestmentIncomeInterest",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of maturities of an entity's investments as well as any other information pertinent to the investments.",
        "label": "Investments Classified by Contractual Maturity Date [Table Text Block]",
        "terseLabel": "Investments Classified by Contractual Maturity Date"
       }
      }
     },
     "localname": "InvestmentsClassifiedByContractualMaturityDateTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Investments, Debt and Equity Securities [Abstract]",
        "terseLabel": "Investments, Debt and Equity Securities [Abstract]"
       }
      }
     },
     "localname": "InvestmentsDebtAndEquitySecuritiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_InvestmentsFairValueDisclosure": {
     "auth_ref": [
      "r754"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.",
        "label": "Investments, Fair Value Disclosure",
        "terseLabel": "Total Marketable Securities"
       }
      }
     },
     "localname": "InvestmentsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock": {
     "auth_ref": [
      "r298",
      "r864",
      "r891",
      "r931",
      "r978"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for  investments in certain debt and equity securities.",
        "label": "Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]",
        "terseLabel": "MARKETABLE SECURITIES"
       }
      }
     },
     "localname": "InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIES"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LeaseCost": {
     "auth_ref": [
      "r812",
      "r814"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lease cost recognized by lessee for lease contract.",
        "label": "Lease, Cost",
        "totalLabel": "Total Lease Cost"
       }
      }
     },
     "localname": "LeaseCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LeaseCostAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Lease, Cost [Abstract]",
        "terseLabel": "Lease, Cost [Abstract]"
       }
      }
     },
     "localname": "LeaseCostAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LeaseCostTableTextBlock": {
     "auth_ref": [
      "r812"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of lessee's lease cost. Includes, but is not limited to, interest expense for finance lease, amortization of right-of-use asset for finance lease, operating lease cost, short-term lease cost, variable lease cost and sublease income.",
        "label": "Lease, Cost [Table Text Block]",
        "terseLabel": "Components of Lease Cost"
       }
      }
     },
     "localname": "LeaseCostTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LeasesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Leases [Abstract]",
        "terseLabel": "Leases [Abstract]"
       }
      }
     },
     "localname": "LeasesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_LesseeFinanceLeasesTextBlock": {
     "auth_ref": [
      "r815"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for finance leases of lessee. Includes, but is not limited to, description of lessee's finance lease and maturity analysis of finance lease liability.",
        "label": "Lessee, Finance Leases [Text Block]",
        "terseLabel": "LEASES"
       }
      }
     },
     "localname": "LesseeFinanceLeasesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASES"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LesseeLeaseDescriptionLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Lessee, Lease, Description [Line Items]",
        "terseLabel": "Lessee, Lease, Description [Line Items]"
       }
      }
     },
     "localname": "LesseeLeaseDescriptionLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails",
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails",
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails",
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LesseeLeaseDescriptionTable": {
     "auth_ref": [
      "r804"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about lessee's leases.",
        "label": "Lessee, Lease, Description [Table]",
        "terseLabel": "Lessee, Lease, Description [Table]"
       }
      }
     },
     "localname": "LesseeLeaseDescriptionTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails",
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails",
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails",
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock": {
     "auth_ref": [
      "r813"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of undiscounted cash flows of lessee's operating lease liability. Includes, but is not limited to, reconciliation of undiscounted cash flows to operating lease liability recognized in statement of financial position.",
        "label": "Lessee, Operating Lease, Liability, Maturity [Table Text Block]",
        "terseLabel": "Future Minimum Lease Payments under Long-Term Operating Leases"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails_1": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease.",
        "label": "Lessee, Operating Lease, Liability, to be Paid",
        "totalLabel": "Future lease payments"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease due after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Lessee, Operating Lease, Liability, to be Paid, after Year Five",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Lessee, Operating Lease, Liability, to be Paid, Year One",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Lessee, Operating Lease, Liability, to be Paid, Year Five",
        "terseLabel": "2026"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearFive",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Lessee, Operating Lease, Liability, to be Paid, Year Four",
        "terseLabel": "2025"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearFour",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Lessee, Operating Lease, Liability, to be Paid, Year Three",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearThree",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Lessee, Operating Lease, Liability, to be Paid, Year Two",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearTwo",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount": {
     "auth_ref": [
      "r813"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails_1": {
       "order": 1.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease.",
        "label": "Lessee, Operating Lease, Liability, Undiscounted Excess Amount",
        "terseLabel": "Less amount representing interest"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityUndiscountedExcessAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeasesTextBlock": {
     "auth_ref": [
      "r815"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for operating leases of lessee. Includes, but is not limited to, description of operating lease and maturity analysis of operating lease liability.",
        "label": "Lessee, Operating Leases [Text Block]",
        "terseLabel": "LEASES"
       }
      }
     },
     "localname": "LesseeOperatingLeasesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASES"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LetterOfCreditMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A document typically issued by a financial institution which acts as a guarantee of payment to a beneficiary, or as the source of payment for a specific transaction (for example, wiring funds to a foreign exporter if and when specified merchandise is accepted pursuant to the terms of the letter of credit).",
        "label": "Letter of Credit [Member]",
        "terseLabel": "Letter of Credit"
       }
      }
     },
     "localname": "LetterOfCreditMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESGuaranteesandObligationsNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LiabilitiesAndStockholdersEquity": {
     "auth_ref": [
      "r42",
      "r166",
      "r308",
      "r772",
      "r826",
      "r870",
      "r901"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of liabilities and equity items, including the portion of equity attributable to noncontrolling interests, if any.",
        "label": "Liabilities and Equity",
        "terseLabel": "Total Liabilities and Capitalization",
        "totalLabel": "Total Liabilities and Capitalization"
       }
      }
     },
     "localname": "LiabilitiesAndStockholdersEquity",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesAndStockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Liabilities and Equity [Abstract]",
        "terseLabel": "LIABILITIES AND CAPITALIZATION",
        "verboseLabel": "LIABILITIES AND CAPITALIZATION"
       }
      }
     },
     "localname": "LiabilitiesAndStockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LiabilitiesCurrent": {
     "auth_ref": [
      "r56",
      "r166",
      "r308",
      "r414",
      "r415",
      "r416",
      "r419",
      "r420",
      "r421",
      "r423",
      "r425",
      "r427",
      "r428",
      "r704",
      "r710",
      "r711",
      "r772",
      "r824",
      "r825",
      "r826"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 1.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer.",
        "label": "Liabilities, Current",
        "terseLabel": "Total Current Liabilities",
        "totalLabel": "Total Current Liabilities"
       }
      }
     },
     "localname": "LiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesCurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Liabilities, Current [Abstract]",
        "terseLabel": "Current Liabilities:",
        "verboseLabel": "Current Liabilities:"
       }
      }
     },
     "localname": "LiabilitiesCurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LiabilitiesOtherThanLongtermDebtNoncurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 2.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregated carrying amounts of obligations as of the balance sheet date, excluding long-term debt, incurred as part of the normal operations that are expected to be paid after one year or beyond the normal operating cycle, if longer. Alternate captions include Total Deferred Credits and Other Liabilities.",
        "label": "Liabilities, Other than Long-term Debt, Noncurrent",
        "terseLabel": "Deferred Credits and Other Liabilities",
        "totalLabel": "Total Deferred Credits and Other Liabilities"
       }
      }
     },
     "localname": "LiabilitiesOtherThanLongtermDebtNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LineOfCredit": {
     "auth_ref": [
      "r28",
      "r869",
      "r894"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.",
        "label": "Long-term Line of Credit",
        "terseLabel": "Borrowings outstanding"
       }
      }
     },
     "localname": "LineOfCredit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LineOfCreditFacilityLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Line of Credit Facility [Line Items]",
        "terseLabel": "Line of Credit Facility [Line Items]"
       }
      }
     },
     "localname": "LineOfCreditFacilityLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTScheduleofDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity": {
     "auth_ref": [
      "r52"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.",
        "label": "Line of Credit Facility, Maximum Borrowing Capacity",
        "netLabel": "Maximum borrowing capacity",
        "terseLabel": "Amount of commercial paper program"
       }
      }
     },
     "localname": "LineOfCreditFacilityMaximumBorrowingCapacity",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESGuaranteesandObligationsNarrativeDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity": {
     "auth_ref": [
      "r52"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).",
        "label": "Line of Credit Facility, Remaining Borrowing Capacity",
        "verboseLabel": "Available Borrowing Capacity"
       }
      }
     },
     "localname": "LineOfCreditFacilityRemainingBorrowingCapacity",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTScheduleofDebtDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LineOfCreditFacilityTable": {
     "auth_ref": [
      "r52",
      "r165"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A table or schedule providing information pertaining to short-term or long-term contractual arrangements with lenders, including letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line.",
        "label": "Line of Credit Facility [Table]",
        "terseLabel": "Line of Credit Facility [Table]"
       }
      }
     },
     "localname": "LineOfCreditFacilityTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTScheduleofDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LineOfCreditMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A contractual arrangement with a lender under which borrowings can be made up to a specific amount at any point in time, and under which borrowings outstanding may be either short-term or long-term, depending upon the particulars.",
        "label": "Line of Credit [Member]",
        "terseLabel": "Line of Credit"
       }
      }
     },
     "localname": "LineOfCreditMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LoanCommitmentsPolicy": {
     "auth_ref": [
      "r735",
      "r736"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy for loan commitments accounted for as derivatives, including the methods and assumptions used to estimate fair value and any associated hedging strategies.",
        "label": "Loan Commitments, Policy [Policy Text Block]",
        "terseLabel": "Transfer of Energy Efficiency Loans"
       }
      }
     },
     "localname": "LoanCommitmentsPolicy",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LoansPayableMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Borrowing supported by a written promise to pay an obligation.",
        "label": "Loans Payable [Member]",
        "terseLabel": "Loans Payable"
       }
      }
     },
     "localname": "LoansPayableMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LongTermContractForPurchaseOfElectricPowerAxis": {
     "auth_ref": [
      "r949"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by contract related to purchases of electric power.",
        "label": "Long-term Contract for Purchase of Electric Power [Axis]",
        "terseLabel": "Long-term Contract for Purchase of Electric Power [Axis]"
       }
      }
     },
     "localname": "LongTermContractForPurchaseOfElectricPowerAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LongTermContractForPurchaseOfElectricPowerDomain": {
     "auth_ref": [
      "r949"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of long-term contract for purchase of electric power.",
        "label": "Long-term Contract for Purchase of Electric Power [Domain]",
        "terseLabel": "Long-term Contract for Purchase of Electric Power [Domain]"
       }
      }
     },
     "localname": "LongTermContractForPurchaseOfElectricPowerDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LongTermContractForPurchaseOfElectricPowerShareOfPlantOutputBeingPurchased": {
     "auth_ref": [
      "r949"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share of plant output being purchased under a long-term contract to purchase electricity from a production plant constructed and financed by a public utility district, cooperative, or other organization.",
        "label": "Long-term Contract for Purchase of Electric Power, Share of Plant Output Being Purchased",
        "terseLabel": "Percent of the facility's output required to be purchased"
       }
      }
     },
     "localname": "LongTermContractForPurchaseOfElectricPowerShareOfPlantOutputBeingPurchased",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_LongTermDebt": {
     "auth_ref": [
      "r28",
      "r437",
      "r447",
      "r448",
      "r449",
      "r869",
      "r896"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.",
        "label": "Long-term Debt",
        "terseLabel": "Long-term debt",
        "verboseLabel": "Long-Term Debt"
       }
      }
     },
     "localname": "LongTermDebt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtCurrent": {
     "auth_ref": [
      "r54"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 2.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.",
        "label": "Long-term Debt, Current Maturities",
        "negatedLabel": "Less Amounts due in One Year",
        "terseLabel": "Long-Term Debt \u2013 Current Portion"
       }
      }
     },
     "localname": "LongTermDebtCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive": {
     "auth_ref": [
      "r175",
      "r411",
      "r441"
     ],
     "calculation": {
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails": {
       "order": 6.0,
       "parentTag": "es_Longtermdebtmaturitiesrepaymentsofprincipaltotal",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Long-Term Debt, Maturity, after Year Five",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths": {
     "auth_ref": [
      "r175",
      "r411",
      "r441"
     ],
     "calculation": {
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails": {
       "order": 1.0,
       "parentTag": "es_Longtermdebtmaturitiesrepaymentsofprincipaltotal",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Long-Term Debt, Maturity, Year One",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive": {
     "auth_ref": [
      "r175",
      "r411",
      "r441"
     ],
     "calculation": {
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails": {
       "order": 5.0,
       "parentTag": "es_Longtermdebtmaturitiesrepaymentsofprincipaltotal",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Long-Term Debt, Maturity, Year Five",
        "terseLabel": "2026"
       }
      }
     },
     "localname": "LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour": {
     "auth_ref": [
      "r175",
      "r411",
      "r441"
     ],
     "calculation": {
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails": {
       "order": 4.0,
       "parentTag": "es_Longtermdebtmaturitiesrepaymentsofprincipaltotal",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Long-Term Debt, Maturity, Year Four",
        "terseLabel": "2025"
       }
      }
     },
     "localname": "LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree": {
     "auth_ref": [
      "r175",
      "r411",
      "r441"
     ],
     "calculation": {
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails": {
       "order": 3.0,
       "parentTag": "es_Longtermdebtmaturitiesrepaymentsofprincipaltotal",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Long-Term Debt, Maturity, Year Three",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo": {
     "auth_ref": [
      "r175",
      "r411",
      "r441"
     ],
     "calculation": {
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails": {
       "order": 2.0,
       "parentTag": "es_Longtermdebtmaturitiesrepaymentsofprincipaltotal",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Long-Term Debt, Maturity, Year Two",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongtermDebtMaturitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtNoncurrent": {
     "auth_ref": [
      "r58"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 3.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.",
        "label": "Long-term Debt, Excluding Current Maturities",
        "terseLabel": "Long-Term Debt",
        "verboseLabel": "Long-term debt"
       }
      }
     },
     "localname": "LongTermDebtNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/LONGTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtNoncurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Long-term Debt, Excluding Current Maturities [Abstract]",
        "terseLabel": "Capitalization:"
       }
      }
     },
     "localname": "LongTermDebtNoncurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LongTermDebtTextBlock": {
     "auth_ref": [
      "r452"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for long-term debt.",
        "label": "Long-term Debt [Text Block]",
        "terseLabel": "LONG-TERM DEBT"
       }
      }
     },
     "localname": "LongTermDebtTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBT"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LongTermInvestmentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Long-term Investments [Abstract]",
        "terseLabel": "Deferred Debits and Other Assets:"
       }
      }
     },
     "localname": "LongTermInvestmentsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by category of items purchased under a long-term purchase commitment.",
        "label": "Category of Item Purchased [Axis]",
        "terseLabel": "Category of Item Purchased [Axis]"
       }
      }
     },
     "localname": "LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "General description of the goods or services to be purchased from the counterparty to the long-term purchase commitment.",
        "label": "Long-term Purchase Commitment, Category of Item Purchased [Domain]",
        "terseLabel": "Long-term Purchase Commitment, Category of Item Purchased [Domain]"
       }
      }
     },
     "localname": "LongTermPurchaseCommitmentCategoryOfItemPurchasedDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LongTermPurchaseCommitmentLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Long-term Purchase Commitment [Line Items]",
        "terseLabel": "Long-term Purchase Commitment [Line Items]"
       }
      }
     },
     "localname": "LongTermPurchaseCommitmentLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofTotalCostsIncurredDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LongTermPurchaseCommitmentMinimumEnergyVolumeRequired": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Energy volume that must be purchased within the specified time period of the agreement to avoid penalties or unfavorable effects on pricing, among other adverse consequences.",
        "label": "Long-term Purchase Commitment, Minimum Energy Volume Required",
        "terseLabel": "Annual purchase requirement (in MWh)"
       }
      }
     },
     "localname": "LongTermPurchaseCommitmentMinimumEnergyVolumeRequired",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "energyItemType"
    },
    "us-gaap_LongTermPurchaseCommitmentTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule setting forth key provisions of an arrangement under which the entity has agreed to purchase goods or services over a period of time greater than one year or the normal operating cycle, if longer, including the item for which expenditures will be made, minimum quantities, milestones, time period and committed amount.",
        "label": "Long-term Purchase Commitment [Table]",
        "terseLabel": "Long-term Purchase Commitment [Table]"
       }
      }
     },
     "localname": "LongTermPurchaseCommitmentTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofTotalCostsIncurredDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LongTermPurchaseCommitmentTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of key provisions of an arrangement under which the entity has agreed to purchase goods or services over a period of time greater than one year or the normal operating cycle, if longer, including the item for which expenditures will be made, minimum quantities, milestones, time period and committed amount.",
        "label": "Long-term Purchase Commitment [Table Text Block]",
        "terseLabel": "Schedule of Estimated Future Annual Costs of Long term Contractual Agreement"
       }
      }
     },
     "localname": "LongTermPurchaseCommitmentTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LongtermDebtTypeAxis": {
     "auth_ref": [
      "r58"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of long-term debt.",
        "label": "Long-term Debt, Type [Axis]",
        "terseLabel": "Long-term Debt, Type [Axis]"
       }
      }
     },
     "localname": "LongtermDebtTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LongtermDebtTypeDomain": {
     "auth_ref": [
      "r58",
      "r412"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Type of long-term debt arrangement, such as notes, line of credit, commercial paper, asset-based financing, project financing, letter of credit financing. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the company, if longer.",
        "label": "Long-term Debt, Type [Domain]",
        "terseLabel": "Long-term Debt, Type [Domain]"
       }
      }
     },
     "localname": "LongtermDebtTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LongtermPurchaseCommitmentPeriod": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Long-term Purchase Commitment, Period",
        "terseLabel": "Contract term"
       }
      }
     },
     "localname": "LongtermPurchaseCommitmentPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_LossContingenciesByNatureOfContingencyAxis": {
     "auth_ref": [
      "r384",
      "r385",
      "r386",
      "r389",
      "r390",
      "r391",
      "r394",
      "r401",
      "r402"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of existing condition, situation, or set of circumstances involving uncertainty as to possible loss to an enterprise that will ultimately be resolved when one or more future events occur or fail to occur.",
        "label": "Loss Contingency Nature [Axis]",
        "terseLabel": "Loss Contingency Nature [Axis]"
       }
      }
     },
     "localname": "LossContingenciesByNatureOfContingencyAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPTropicalStormIsaiasResponseInvestigationDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/REVENUESNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LossContingenciesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Loss Contingencies [Line Items]",
        "terseLabel": "Loss Contingencies [Line Items]"
       }
      }
     },
     "localname": "LossContingenciesLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPTropicalStormIsaiasResponseInvestigationDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESGuaranteesandObligationsNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofNumberofSitesandReservesDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofReconciliationofActivityinEnvironmentalReserveDetails",
      "http://www.eversource.com/role/REVENUESNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LossContingenciesTable": {
     "auth_ref": [
      "r384",
      "r385",
      "r386",
      "r389",
      "r390",
      "r391",
      "r394",
      "r401",
      "r402"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Discloses the specific components (such as the nature, name, and date) of the loss contingency and gives an estimate of the possible loss or range of loss, or states that a reasonable estimate cannot be made. Excludes environmental contingencies, warranties and unconditional purchase obligations.",
        "label": "Loss Contingencies [Table]",
        "terseLabel": "Loss Contingencies [Table]"
       }
      }
     },
     "localname": "LossContingenciesTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPTropicalStormIsaiasResponseInvestigationDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESGuaranteesandObligationsNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofNumberofSitesandReservesDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofReconciliationofActivityinEnvironmentalReserveDetails",
      "http://www.eversource.com/role/REVENUESNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LossContingencyDamagesAwardedValue": {
     "auth_ref": [
      "r384",
      "r387",
      "r392"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of damages awarded to the plaintiff in the legal matter.",
        "label": "Loss Contingency, Damages Awarded, Value",
        "verboseLabel": "Net of damages awarded"
       }
      }
     },
     "localname": "LossContingencyDamagesAwardedValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LossContingencyDamagesPaidValue": {
     "auth_ref": [
      "r384",
      "r387",
      "r392"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of damages paid to the plaintiff in the legal matter.",
        "label": "Loss Contingency, Damages Paid, Value",
        "terseLabel": "Damages paid"
       }
      }
     },
     "localname": "LossContingencyDamagesPaidValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LossContingencyDamagesSoughtValue": {
     "auth_ref": [
      "r384",
      "r387",
      "r392"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The value (monetary amount) of the award the plaintiff seeks in the legal matter.",
        "label": "Loss Contingency, Damages Sought, Value",
        "terseLabel": "Damages sought"
       }
      }
     },
     "localname": "LossContingencyDamagesSoughtValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LossContingencyEstimateOfPossibleLoss": {
     "auth_ref": [
      "r388",
      "r393",
      "r401"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.",
        "label": "Loss Contingency, Estimate of Possible Loss",
        "terseLabel": "Loss contingency, estimate of possible earnings impact"
       }
      }
     },
     "localname": "LossContingencyEstimateOfPossibleLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPTropicalStormIsaiasResponseInvestigationDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LossContingencyNatureDomain": {
     "auth_ref": [
      "r384",
      "r385",
      "r386",
      "r389",
      "r390",
      "r391",
      "r394",
      "r401",
      "r402"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "An existing condition, situation, or set of circumstances involving uncertainty as to possible loss to an enterprise that will ultimately be resolved when one or more future events occur or fail to occur. Resolution of the uncertainty may confirm the incurrence of a loss or impairment of an asset or the incurrence of a liability.",
        "label": "Loss Contingency, Nature [Domain]",
        "terseLabel": "Loss Contingency, Nature [Domain]"
       }
      }
     },
     "localname": "LossContingencyNatureDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPTropicalStormIsaiasResponseInvestigationDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/REVENUESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LossContingencyPendingClaimsNumber": {
     "auth_ref": [
      "r387"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of pending claims pertaining to a loss contingency.",
        "label": "Loss Contingency, Pending Claims, Number",
        "terseLabel": "Loss contingency, pending claims, number"
       }
      }
     },
     "localname": "LossContingencyPendingClaimsNumber",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "us-gaap_MarketableSecurities": {
     "auth_ref": [
      "r875"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment in marketable security.",
        "label": "Marketable Securities",
        "terseLabel": "Marketable securities held in nuclear decommissioning trusts"
       }
      }
     },
     "localname": "MarketableSecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESEquitySecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_MarketableSecuritiesNoncurrent": {
     "auth_ref": [
      "r45"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 4.0,
       "parentTag": "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment in marketable security, classified as noncurrent.",
        "label": "Marketable Securities, Noncurrent",
        "terseLabel": "Marketable Securities"
       }
      }
     },
     "localname": "MarketableSecuritiesNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_MeasurementInputTypeAxis": {
     "auth_ref": [
      "r757"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of measurement input used to determine value of asset and liability.",
        "label": "Measurement Input Type [Axis]",
        "terseLabel": "Measurement Input Type [Axis]"
       }
      }
     },
     "localname": "MeasurementInputTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_MeasurementInputTypeDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measurement input used to determine value of asset and liability.",
        "label": "Measurement Input Type [Domain]",
        "terseLabel": "Measurement Input Type [Domain]"
       }
      }
     },
     "localname": "MeasurementInputTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSUnobservableInputsUtilizedDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_MovementInValuationAllowancesAndReservesRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]",
        "terseLabel": "SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]"
       }
      }
     },
     "localname": "MovementInValuationAllowancesAndReservesRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_MunicipalBondsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-term debt securities issued by state, city or local governments or the agencies operated by state, city or local governments.",
        "label": "Municipal Bonds [Member]",
        "terseLabel": "Municipal Bonds"
       }
      }
     },
     "localname": "MunicipalBondsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_NetCashProvidedByUsedInFinancingActivities": {
     "auth_ref": [
      "r145"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 3.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.",
        "label": "Net Cash Provided by (Used in) Financing Activities",
        "totalLabel": "Net Cash Flows Provided by Financing Activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInFinancingActivities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Cash Provided by (Used in) Financing Activities [Abstract]",
        "terseLabel": "Financing Activities:",
        "verboseLabel": "Financing Activities:"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInFinancingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInInvestingActivities": {
     "auth_ref": [
      "r145"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 2.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
       "weight": 1.0
      },
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.",
        "label": "Net Cash Provided by (Used in) Investing Activities",
        "totalLabel": "Net Cash Flows Used in Investing Activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInInvestingActivities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Cash Provided by (Used in) Investing Activities [Abstract]",
        "terseLabel": "Investing Activities:",
        "verboseLabel": "Investing Activities:"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInInvestingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInOperatingActivities": {
     "auth_ref": [
      "r145",
      "r150",
      "r153"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 1.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
       "weight": 1.0
      },
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.",
        "label": "Net Cash Provided by (Used in) Operating Activities",
        "totalLabel": "Net Cash Flows Provided by Operating Activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInOperatingActivities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Cash Provided by (Used in) Operating Activities [Abstract]",
        "terseLabel": "Operating Activities:",
        "verboseLabel": "Operating Activities:"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetIncomeLoss": {
     "auth_ref": [
      "r12",
      "r100",
      "r103",
      "r109",
      "r115",
      "r153",
      "r166",
      "r190",
      "r194",
      "r195",
      "r197",
      "r198",
      "r202",
      "r203",
      "r212",
      "r242",
      "r248",
      "r252",
      "r255",
      "r258",
      "r308",
      "r414",
      "r415",
      "r416",
      "r419",
      "r420",
      "r421",
      "r423",
      "r425",
      "r427",
      "r428",
      "r752",
      "r772",
      "r877",
      "r905"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      },
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME": {
       "order": 1.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax",
       "weight": 1.0
      },
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 1.0,
       "parentTag": "us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic",
       "weight": 1.0
      },
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      },
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.",
        "label": "Net Income (Loss) Attributable to Parent",
        "terseLabel": "Net Income",
        "totalLabel": "Net Income"
       }
      }
     },
     "localname": "NetIncomeLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFCOMPREHENSIVEINCOMEDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetIncomeLossAttributableToNoncontrollingInterest": {
     "auth_ref": [
      "r100",
      "r103",
      "r109",
      "r202",
      "r203",
      "r706",
      "r717"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 2.0,
       "parentTag": "us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of Net Income (Loss) attributable to noncontrolling interest.",
        "label": "Net Income (Loss) Attributable to Noncontrolling Interest",
        "negatedTerseLabel": "Net Income Attributable to Noncontrolling Interests",
        "terseLabel": "Net Income Attributable to Noncontrolling Interests"
       }
      }
     },
     "localname": "NetIncomeLossAttributableToNoncontrollingInterest",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic": {
     "auth_ref": [
      "r194",
      "r195",
      "r197",
      "r198",
      "r205",
      "r206",
      "r213",
      "r216",
      "r242",
      "r248",
      "r252",
      "r255",
      "r258"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.",
        "label": "Net Income (Loss) Available to Common Stockholders, Basic",
        "terseLabel": "Net Income Attributable to Common Shareholders",
        "totalLabel": "Net Income Attributable to Common Shareholders",
        "verboseLabel": "Net Income Attributable to Common Shareholders"
       }
      }
     },
     "localname": "NetIncomeLossAvailableToCommonStockholdersBasic",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetRegulatoryAssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Regulatory Assets [Abstract]",
        "terseLabel": "Net Regulatory Assets [Abstract]"
       }
      }
     },
     "localname": "NetRegulatoryAssetsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy pertaining to new accounting pronouncements that may impact the entity's financial reporting. Includes, but is not limited to, quantification of the expected or actual impact.",
        "label": "New Accounting Pronouncements, Policy [Policy Text Block]",
        "terseLabel": "Accounting Standards"
       }
      }
     },
     "localname": "NewAccountingPronouncementsPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_NonoperatingIncomeExpense": {
     "auth_ref": [
      "r125"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 3.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).",
        "label": "Nonoperating Income (Expense)",
        "terseLabel": "Other Income, Net"
       }
      }
     },
     "localname": "NonoperatingIncomeExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NonoperatingIncomeExpenseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Nonoperating Income (Expense) [Abstract]",
        "terseLabel": "Other Income, Net:"
       }
      }
     },
     "localname": "NonoperatingIncomeExpenseAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NotesAndLoansReceivableNetCurrent": {
     "auth_ref": [
      "r13",
      "r14",
      "r33",
      "r268",
      "r269",
      "r872"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of financing receivable, classified as current. Includes, but is not limited to, notes and loan receivable.",
        "label": "Financing Receivable, after Allowance for Credit Loss, Current",
        "terseLabel": "Loans transferred receivable current"
       }
      }
     },
     "localname": "NotesAndLoansReceivableNetCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTransferofEnergyEfficiencyLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NotesAndLoansReceivableNetNoncurrent": {
     "auth_ref": [
      "r35"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of financing receivable, classified as noncurrent.",
        "label": "Financing Receivable, after Allowance for Credit Loss, Noncurrent",
        "terseLabel": "Loans transferred receivable non-current"
       }
      }
     },
     "localname": "NotesAndLoansReceivableNetNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTransferofEnergyEfficiencyLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NotesPayable": {
     "auth_ref": [
      "r28",
      "r869",
      "r896"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 1.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.",
        "label": "Notes Payable",
        "terseLabel": "Notes Payable",
        "verboseLabel": "Borrowings Outstanding"
       }
      }
     },
     "localname": "NotesPayable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTScheduleofDebtDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NotesPayableRelatedPartiesClassifiedCurrent": {
     "auth_ref": [
      "r49",
      "r171",
      "r820"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 7.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount for notes payable (written promise to pay), due to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
        "label": "Notes Payable, Related Parties, Current",
        "terseLabel": "Notes Payable to Eversource Parent",
        "verboseLabel": "Notes payable to related parties"
       }
      }
     },
     "localname": "NotesPayableRelatedPartiesClassifiedCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NotesReceivableRelatedPartiesCurrent": {
     "auth_ref": [
      "r64",
      "r171",
      "r819"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amounts due from parties associated with the reporting entity as evidenced by a written promise to pay, due within 1 year (or 1 business cycle).",
        "label": "Notes Receivable, Related Parties, Current",
        "terseLabel": "Notes Receivable from Subsidiaries"
       }
      }
     },
     "localname": "NotesReceivableRelatedPartiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NotesReceivableRelatedPartiesNoncurrent": {
     "auth_ref": [
      "r24",
      "r34",
      "r171",
      "r819"
     ],
     "calculation": {
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amounts due from parties associated with the reporting entity as evidenced by a written promise to pay, due after 1 year (or 1 business cycle).",
        "label": "Notes Receivable, Related Parties, Noncurrent",
        "terseLabel": "Notes Receivable from Subsidiaries"
       }
      }
     },
     "localname": "NotesReceivableRelatedPartiesNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NumberOfReportableSegments": {
     "auth_ref": [
      "r230"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.",
        "label": "Number of Reportable Segments",
        "terseLabel": "Number of reportable segments"
       }
      }
     },
     "localname": "NumberOfReportableSegments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SEGMENTINFORMATIONNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent": {
     "auth_ref": [
      "r97"
     ],
     "calculation": {
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount before tax and reclassification adjustments of other comprehensive income (loss) attributable to parent.",
        "label": "OCI, before Reclassifications, before Tax, Attributable to Parent",
        "terseLabel": "OCI Before Reclassifications"
       }
      }
     },
     "localname": "OciBeforeReclassificationsBeforeTaxAttributableToParent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OilAndGasOperationAndMaintenanceMember": {
     "auth_ref": [
      "r502"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Process related to operation and maintenance of wells and related equipment and facility used for production of viscous liquid derived from petroleum and flammable gas occurring naturally underground. Includes, but is not limited to, depreciation and applicable operating cost to support equipment and facility.",
        "label": "Oil and Gas, Operation and Maintenance [Member]",
        "terseLabel": "Oil and Gas, Operation and Maintenance"
       }
      }
     },
     "localname": "OilAndGasOperationAndMaintenanceMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_OperatingExpenses": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 2.0,
       "parentTag": "us-gaap_OperatingIncomeLoss",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.",
        "label": "Operating Expenses",
        "totalLabel": "Total Operating Expenses"
       }
      }
     },
     "localname": "OperatingExpenses",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingExpensesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Operating Expenses [Abstract]",
        "terseLabel": "Operating Expenses:",
        "verboseLabel": "Operating Expenses:"
       }
      }
     },
     "localname": "OperatingExpensesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OperatingIncomeLoss": {
     "auth_ref": [
      "r242",
      "r248",
      "r252",
      "r255",
      "r258"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 1.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic",
       "weight": 1.0
      },
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The net result for the period of deducting operating expenses from operating revenues.",
        "label": "Operating Income (Loss)",
        "terseLabel": "Operating Income (Loss)",
        "totalLabel": "Operating Income"
       }
      }
     },
     "localname": "OperatingIncomeLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseCost": {
     "auth_ref": [
      "r806",
      "r814"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_LeaseCost",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.",
        "label": "Operating Lease, Cost",
        "terseLabel": "Operating Lease Cost"
       }
      }
     },
     "localname": "OperatingLeaseCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLeaseIncome": {
     "auth_ref": [
      "r224",
      "r816",
      "r817"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of operating lease income from lease payments and variable lease payments paid and payable to lessor. Includes, but is not limited to, variable lease payments not included in measurement of lease receivable.",
        "label": "Operating Lease, Lease Income",
        "terseLabel": "Lease revenue"
       }
      }
     },
     "localname": "OperatingLeaseLeaseIncome",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Lessee, Operating Lease, Liability, Payment, Due [Abstract]",
        "terseLabel": "Operating Leases"
       }
      }
     },
     "localname": "OperatingLeaseLiabilitiesPaymentsDueAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OperatingLeaseLiability": {
     "auth_ref": [
      "r798"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails_1": {
       "order": 2.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      },
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Present value of lessee's discounted obligation for lease payments from operating lease.",
        "label": "Operating Lease, Liability",
        "terseLabel": "Present value of future minimum lease payments",
        "totalLabel": "Total Operating Lease Liabilities"
       }
      }
     },
     "localname": "OperatingLeaseLiability",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESFutureMinimumLeasePaymentsunderLongTermLeasesDetails",
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLiabilityCurrent": {
     "auth_ref": [
      "r798"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_OperatingLeaseLiability",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.",
        "label": "Operating Lease, Liability, Current",
        "terseLabel": "Current Portion"
       }
      }
     },
     "localname": "OperatingLeaseLiabilityCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList": {
     "auth_ref": [
      "r799"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates line item in statement of financial position that includes current operating lease liability.",
        "label": "Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]",
        "terseLabel": "Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]"
       }
      }
     },
     "localname": "OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "enumerationSetItemType"
    },
    "us-gaap_OperatingLeaseLiabilityNoncurrent": {
     "auth_ref": [
      "r798"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_OperatingLeaseLiability",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent.",
        "label": "Operating Lease, Liability, Noncurrent",
        "terseLabel": "Long-Term"
       }
      }
     },
     "localname": "OperatingLeaseLiabilityNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList": {
     "auth_ref": [
      "r799"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates line item in statement of financial position that includes noncurrent operating lease liability.",
        "label": "Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]",
        "terseLabel": "Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]"
       }
      }
     },
     "localname": "OperatingLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "enumerationSetItemType"
    },
    "us-gaap_OperatingLeasePayments": {
     "auth_ref": [
      "r803",
      "r808"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.",
        "label": "Operating Lease, Payments",
        "terseLabel": "Operating Cash Flows from Operating Leases"
       }
      }
     },
     "localname": "OperatingLeasePayments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseRightOfUseAsset": {
     "auth_ref": [
      "r797"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's right to use underlying asset under operating lease.",
        "label": "Operating Lease, Right-of-Use Asset",
        "terseLabel": "Right-of-use-Assets, Net"
       }
      }
     },
     "localname": "OperatingLeaseRightOfUseAsset",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList": {
     "auth_ref": [
      "r799"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates line item in statement of financial position that includes operating lease right-of-use asset.",
        "label": "Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]",
        "terseLabel": "Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]"
       }
      }
     },
     "localname": "OperatingLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESSupplementalBalanceSheetInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "enumerationSetItemType"
    },
    "us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent": {
     "auth_ref": [
      "r811",
      "r814"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average discount rate for operating lease calculated at point in time.",
        "label": "Operating Lease, Weighted Average Discount Rate, Percent",
        "terseLabel": "Operating Leases"
       }
      }
     },
     "localname": "OperatingLeaseWeightedAverageDiscountRatePercent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1": {
     "auth_ref": [
      "r810",
      "r814"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
        "label": "Operating Lease, Weighted Average Remaining Lease Term",
        "terseLabel": "Operating Leases"
       }
      }
     },
     "localname": "OperatingLeaseWeightedAverageRemainingLeaseTerm1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_OperatingLossCarryforwards": {
     "auth_ref": [
      "r658"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.",
        "label": "Operating Loss Carryforwards",
        "terseLabel": "Operating Loss Carryforwards"
       }
      }
     },
     "localname": "OperatingLossCarryforwards",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTaxCreditsandLossCarryforwardsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLossCarryforwardsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Operating Loss Carryforwards [Line Items]",
        "terseLabel": "Operating Loss Carryforwards [Line Items]"
       }
      }
     },
     "localname": "OperatingLossCarryforwardsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails",
      "http://www.eversource.com/role/INCOMETAXESTaxCreditsandLossCarryforwardsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OperatingLossCarryforwardsTable": {
     "auth_ref": [
      "r659"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule reflecting pertinent information, such as tax authority, amounts, and expiration dates, of net operating loss carryforwards, including an assessment of the likelihood of utilization.",
        "label": "Operating Loss Carryforwards [Table]",
        "terseLabel": "Operating Loss Carryforwards [Table]"
       }
      }
     },
     "localname": "OperatingLossCarryforwardsTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails",
      "http://www.eversource.com/role/INCOMETAXESTaxCreditsandLossCarryforwardsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OperatingSegmentsMember": {
     "auth_ref": [
      "r247",
      "r248",
      "r249",
      "r250",
      "r252",
      "r258"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Identifies components of an entity that engage in business activities from which they may earn revenue and incur expenses, including transactions with other components of the same entity.",
        "label": "Operating Segments [Member]",
        "terseLabel": "Operating Segments"
       }
      }
     },
     "localname": "OperatingSegmentsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESNarrativeDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_OtherAssetsCurrent": {
     "auth_ref": [
      "r71",
      "r826"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 6.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of current assets classified as other.",
        "label": "Other Assets, Current",
        "terseLabel": "Prepayments and Other Current Assets",
        "verboseLabel": "Prepayments and Other Current Assets"
       }
      }
     },
     "localname": "OtherAssetsCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherAssetsNoncurrent": {
     "auth_ref": [
      "r48"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 5.0,
       "parentTag": "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
       "weight": 1.0
      },
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of noncurrent assets classified as other.",
        "label": "Other Assets, Noncurrent",
        "terseLabel": "Other Long-Term Assets",
        "verboseLabel": "Other Long-Term Assets"
       }
      }
     },
     "localname": "OtherAssetsNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostCreditArisingDuringPeriodBeforeTax": {
     "auth_ref": [
      "r92",
      "r94",
      "r560"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before tax, of cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).",
        "label": "Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), before Tax",
        "terseLabel": "Prior Service Cost Arising During the Year"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostCreditArisingDuringPeriodBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax": {
     "auth_ref": [
      "r86",
      "r87",
      "r94"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME": {
       "order": 2.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after tax and adjustment, of unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) and unrealized gain (loss) on investment in debt security measured at amortized cost (held-to-maturity) from transfer to available-for-sale.",
        "label": "OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax",
        "terseLabel": "Changes in Unrealized (Losses)/Gains on Marketable Securities",
        "verboseLabel": "Changes in Unrealized (Losses)/Gains on Marketable Securities"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFCOMPREHENSIVEINCOMEDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMPREHENSIVEINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax": {
     "auth_ref": [
      "r85",
      "r94"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME": {
       "order": 1.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after tax and reclassification, of gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.",
        "label": "Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax",
        "terseLabel": "Qualified Cash Flow Hedging Instruments",
        "verboseLabel": "Qualified Cash Flow Hedging Instruments"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFCOMPREHENSIVEINCOMEDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMPREHENSIVEINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTax": {
     "auth_ref": [
      "r101",
      "r104",
      "r107",
      "r108",
      "r110",
      "r116",
      "r479",
      "r782",
      "r787",
      "r788",
      "r878",
      "r906"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME": {
       "order": 2.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after tax and reclassification adjustments of other comprehensive income (loss).",
        "label": "Other Comprehensive Income (Loss), Net of Tax",
        "terseLabel": "Other Comprehensive Income/(Loss), Net of Tax",
        "totalLabel": "Other Comprehensive Income/(Loss), Net of Tax"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFCOMPREHENSIVEINCOMEDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMPREHENSIVEINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Other Comprehensive Income (Loss), Net of Tax [Abstract]",
        "terseLabel": "Other Comprehensive Income/(Loss), Net of Tax:",
        "verboseLabel": "Other Comprehensive Income/(Loss), Net of Tax:"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFCOMPREHENSIVEINCOMEDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMPREHENSIVEINCOME"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent": {
     "auth_ref": [
      "r101",
      "r104",
      "r700",
      "r701",
      "r708"
     ],
     "calculation": {
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after tax of other comprehensive income (loss) attributable to parent entity.",
        "label": "Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent",
        "totalLabel": "Net OCI"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsAndTax": {
     "auth_ref": [
      "r91",
      "r94"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).",
        "label": "Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax",
        "negatedTerseLabel": "Prior Service (Cost)/Credit Reclassified as Net Periodic Benefit (Expense)/Income"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsAndTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsAndTaxAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax [Abstract]",
        "terseLabel": "OCI"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsAndTaxAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax": {
     "auth_ref": [
      "r91",
      "r94"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME": {
       "order": 3.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan.",
        "label": "Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax",
        "negatedLabel": "Change in Funded Status of Pension, SERP and PBOP Benefit Plans",
        "negatedTerseLabel": "Changes in Funded Status of SERP Benefit Plan"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFCOMPREHENSIVEINCOMEDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeReclassificationAdjustmentsTax": {
     "auth_ref": [
      "r91",
      "r95",
      "r700"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income for defined benefit plan.",
        "label": "Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, Tax",
        "terseLabel": "Related tax effect recognized in AOCI"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeReclassificationAdjustmentsTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax": {
     "auth_ref": [
      "r89",
      "r94",
      "r560"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before tax, of gain (loss) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.",
        "label": "Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax",
        "negatedTerseLabel": "Actuarial (Gains)/Losses Arising During the Year"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax": {
     "auth_ref": [
      "r94",
      "r98",
      "r99",
      "r560"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before tax, of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan.",
        "label": "Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax",
        "terseLabel": "Actuarial Losses Reclassified as Net Periodic Benefit Expense"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherCurrentLiabilitiesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Primary financial statement caption encompassing other current liabilities.",
        "label": "Other Current Liabilities [Member]",
        "terseLabel": "Current Derivative Liabilities",
        "verboseLabel": "Other Current Liabilities"
       }
      }
     },
     "localname": "OtherCurrentLiabilitiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_OtherDebtSecuritiesMember": {
     "auth_ref": [
      "r293",
      "r329",
      "r542",
      "r761"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Investments in debt securities classified as other.",
        "label": "Other Debt Obligations [Member]",
        "terseLabel": "Other Fixed Income Securities"
       }
      }
     },
     "localname": "OtherDebtSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_OtherInventoryCapitalizedCosts": {
     "auth_ref": [
      "r67"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before valuation and last-in first out (LIFO) reserves, of costs capitalized in inventory classified as other, expected to be sold, or consumed within one year or operating cycle, if longer.",
        "label": "Other Inventory, Capitalized Costs, Gross",
        "terseLabel": "Other inventory, capitalized costs, gross"
       }
      }
     },
     "localname": "OtherInventoryCapitalizedCosts",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherLiabilitiesCurrent": {
     "auth_ref": [
      "r19",
      "r20",
      "r55",
      "r826"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 6.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of liabilities classified as other, due within one year or the normal operating cycle, if longer.",
        "label": "Other Liabilities, Current",
        "terseLabel": "Other Current Liabilities",
        "verboseLabel": "Accrued Interest (included in Other Current Liabilities)"
       }
      }
     },
     "localname": "OtherLiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherLiabilitiesNoncurrent": {
     "auth_ref": [
      "r59"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 6.0,
       "parentTag": "us-gaap_LiabilitiesOtherThanLongtermDebtNoncurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer.",
        "label": "Other Liabilities, Noncurrent",
        "terseLabel": "Other Long-Term Liabilities"
       }
      }
     },
     "localname": "OtherLiabilitiesNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherLiabilitiesNoncurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Other Liabilities, Noncurrent [Abstract]",
        "terseLabel": "Deferred Credits and Other Liabilities:"
       }
      }
     },
     "localname": "OtherLiabilitiesNoncurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OtherNoncashIncomeExpense": {
     "auth_ref": [
      "r153"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 12.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      },
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of income (expense) included in net income that results in no cash inflow (outflow), classified as other.",
        "label": "Other Noncash Income (Expense)",
        "negatedTerseLabel": "Other"
       }
      }
     },
     "localname": "OtherNoncashIncomeExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherNoncurrentAssetsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Primary financial statement caption encompassing other noncurrent assets.",
        "label": "Other Noncurrent Assets [Member]",
        "terseLabel": "Long-Term Derivative Assets",
        "verboseLabel": "Other Long-Term Assets"
       }
      }
     },
     "localname": "OtherNoncurrentAssetsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_OtherNoncurrentLiabilitiesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Primary financial statement caption encompassing other noncurrent liabilities.",
        "label": "Other Noncurrent Liabilities [Member]",
        "terseLabel": "Long-Term Derivative Liabilities"
       }
      }
     },
     "localname": "OtherNoncurrentLiabilitiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEversourceandNSTARElectricBostonHarborCivilActionDetails",
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_OtherNonoperatingIncomeExpense": {
     "auth_ref": [
      "r126"
     ],
     "calculation": {
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of income (expense) related to nonoperating activities, classified as other.",
        "label": "Other Nonoperating Income (Expense)",
        "terseLabel": "Other Income, Net"
       }
      }
     },
     "localname": "OtherNonoperatingIncomeExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember": {
     "auth_ref": [
      "r514",
      "r516",
      "r519",
      "r520",
      "r521",
      "r522",
      "r523",
      "r524",
      "r525",
      "r526",
      "r527",
      "r528",
      "r529",
      "r530",
      "r531",
      "r532",
      "r533",
      "r534",
      "r535",
      "r536",
      "r537",
      "r538",
      "r539",
      "r541",
      "r542",
      "r543",
      "r544",
      "r545",
      "r546",
      "r547",
      "r548",
      "r550",
      "r551",
      "r552",
      "r553",
      "r554",
      "r555",
      "r556",
      "r557",
      "r558",
      "r559",
      "r560",
      "r561",
      "r563",
      "r565",
      "r566",
      "r568",
      "r569",
      "r571",
      "r576",
      "r577",
      "r578",
      "r579",
      "r580",
      "r581",
      "r582",
      "r583",
      "r584",
      "r585",
      "r586",
      "r587",
      "r589",
      "r590",
      "r591",
      "r592",
      "r593",
      "r594"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Plan designed to provide other postretirement benefits. Includes, but is not limited to, defined benefit and defined contribution plans. Excludes pension benefits.",
        "label": "Other Postretirement Benefits Plan [Member]",
        "terseLabel": "Other Postretirement Benefits Plan"
       }
      }
     },
     "localname": "OtherPostretirementBenefitPlansDefinedBenefitMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssumptionsusedToCalculatePensionandSERPandPBOPDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofEstimatedFutureBenefitPaymentsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PaymentGuaranteeMember": {
     "auth_ref": [
      "r398",
      "r409"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A contract that contingently requires the guarantor to make payments (either in cash, financial instrument, other assets, shares of its stock, or provision of services) to the guaranteed party based on changes in an underlying that is related to an asset, a liability, or an equity security of the guaranteed party.",
        "label": "Payment Guarantee [Member]",
        "terseLabel": "Payment Guarantee"
       }
      }
     },
     "localname": "PaymentGuaranteeMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PaymentsForProceedsFromOtherInvestingActivities": {
     "auth_ref": [
      "r131",
      "r134"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 7.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      },
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash (inflow) outflow from investing activities classified as other.",
        "label": "Payments for (Proceeds from) Other Investing Activities",
        "negatedLabel": "Other Investing Activities",
        "negatedTerseLabel": "Other Investing Activities"
       }
      }
     },
     "localname": "PaymentsForProceedsFromOtherInvestingActivities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsOfDividendsCommonStock": {
     "auth_ref": [
      "r138"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.",
        "label": "Payments of Ordinary Dividends, Common Stock",
        "negatedLabel": "Cash Dividends on Common Shares",
        "negatedTerseLabel": "Cash Dividends on Common Shares"
       }
      }
     },
     "localname": "PaymentsOfDividendsCommonStock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock": {
     "auth_ref": [
      "r138"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow in the form of ordinary dividends to preferred shareholders of the parent entity.",
        "label": "Payments of Ordinary Dividends, Preferred Stock and Preference Stock",
        "negatedLabel": "Cash Dividends on Preferred Stock"
       }
      }
     },
     "localname": "PaymentsOfDividendsPreferredStockAndPreferenceStock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireBusinessesGross": {
     "auth_ref": [
      "r132",
      "r695"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.",
        "label": "Payments to Acquire Businesses, Gross",
        "negatedLabel": "Acquisition of Assets of Columbia Gas of Massachusetts, Net of Restricted Cash"
       }
      }
     },
     "localname": "PaymentsToAcquireBusinessesGross",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireEquityMethodInvestments": {
     "auth_ref": [
      "r132"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.",
        "label": "Payments to Acquire Equity Method Investments",
        "negatedLabel": "Investments in Unconsolidated Affiliates, Net",
        "terseLabel": "Payments to acquire investments"
       }
      }
     },
     "localname": "PaymentsToAcquireEquityMethodInvestments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireMarketableSecurities": {
     "auth_ref": [
      "r279"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow for purchase of marketable security.",
        "label": "Payments to Acquire Marketable Securities",
        "negatedLabel": "Purchases of Marketable Securities"
       }
      }
     },
     "localname": "PaymentsToAcquireMarketableSecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquirePropertyPlantAndEquipment": {
     "auth_ref": [
      "r133"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.",
        "label": "Payments to Acquire Property, Plant, and Equipment",
        "negatedLabel": "Investments in Property, Plant and Equipment",
        "netLabel": "Increase to investing cash outflows in investments in property, plant and equipment",
        "terseLabel": "Cash Flows Used for Investments in Plant"
       }
      }
     },
     "localname": "PaymentsToAcquirePropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PensionAndOtherPostretirementBenefitContributions": {
     "auth_ref": [
      "r149"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow for pension and other postretirement benefits. Includes, but is not limited to, employer contribution to fund plan asset and payment to retiree.",
        "label": "Payment for Pension and Other Postretirement Benefits",
        "negatedLabel": "Pension and PBOP Contributions",
        "negatedTerseLabel": "Pension Contributions"
       }
      }
     },
     "localname": "PensionAndOtherPostretirementBenefitContributions",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PensionAndOtherPostretirementBenefitExpense": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cost (reversal of cost) for pension and other postretirement benefits.",
        "label": "Pension and Other Postretirement Benefits Cost (Reversal of Cost)",
        "terseLabel": "Pension, SERP and PBOP (Income)/Expense, Net",
        "verboseLabel": "Pension, SERP and PBOP (Income)/Expense, Net"
       }
      }
     },
     "localname": "PensionAndOtherPostretirementBenefitExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent": {
     "auth_ref": [
      "r29",
      "r516",
      "r517",
      "r539",
      "r586"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 5.0,
       "parentTag": "us-gaap_LiabilitiesOtherThanLongtermDebtNoncurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as noncurrent.",
        "label": "Liability, Defined Benefit Plan, Noncurrent",
        "terseLabel": "Accrued Pension, SERP and PBOP",
        "verboseLabel": "Liability"
       }
      }
     },
     "localname": "PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PensionPlansDefinedBenefitMember": {
     "auth_ref": [
      "r513",
      "r516",
      "r519",
      "r520",
      "r521",
      "r522",
      "r523",
      "r524",
      "r525",
      "r526",
      "r527",
      "r528",
      "r529",
      "r530",
      "r531",
      "r532",
      "r533",
      "r534",
      "r535",
      "r536",
      "r537",
      "r538",
      "r539",
      "r541",
      "r542",
      "r543",
      "r544",
      "r545",
      "r546",
      "r547",
      "r548",
      "r549",
      "r550",
      "r551",
      "r552",
      "r553",
      "r554",
      "r555",
      "r556",
      "r557",
      "r558",
      "r559",
      "r560",
      "r561",
      "r563",
      "r565",
      "r566",
      "r568",
      "r569",
      "r571",
      "r576",
      "r577",
      "r578",
      "r579",
      "r580",
      "r581",
      "r582",
      "r583",
      "r584",
      "r585",
      "r586",
      "r587",
      "r589",
      "r590",
      "r604",
      "r605",
      "r606",
      "r607"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Plan designed to provide participant with pension benefits. Includes, but is not limited to, defined benefit and defined contribution plans. Excludes other postretirement benefits.",
        "label": "Pension Plan [Member]",
        "terseLabel": "Pension Plan"
       }
      }
     },
     "localname": "PensionPlansDefinedBenefitMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssumptionsusedToCalculatePensionandSERPandPBOPDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofEstimatedFutureBenefitPaymentsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofFundedStatusDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PerformanceGuaranteeMember": {
     "auth_ref": [
      "r399"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "An agreement (contract) that requires the guarantor to make payments to a guaranteed party based on another entity's failure to perform under an obligating agreement. This may include the issuance of a performance standby letter of credit which requires the guarantor to make payments if a specified party fails to perform under a nonfinancial contractual obligation.",
        "label": "Performance Guarantee [Member]",
        "terseLabel": "Performance Guarantee"
       }
      }
     },
     "localname": "PerformanceGuaranteeMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PerformanceSharesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share-based payment arrangement awarded for meeting performance target.",
        "label": "Performance Shares [Member]",
        "terseLabel": "Performance Shares"
       }
      }
     },
     "localname": "PerformanceSharesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PlanAssetCategoriesDomain": {
     "auth_ref": [
      "r541",
      "r542",
      "r543",
      "r544",
      "r545",
      "r546",
      "r547",
      "r548",
      "r568",
      "r586"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Defined benefit plan asset investment.",
        "label": "Defined Benefit Plan, Plan Assets, Category [Domain]",
        "terseLabel": "Defined Benefit Plan, Plan Assets, Category [Domain]"
       }
      }
     },
     "localname": "PlanAssetCategoriesDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PlanNameAxis": {
     "auth_ref": [
      "r612",
      "r623"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by plan name for share-based payment arrangement.",
        "label": "Plan Name [Axis]",
        "terseLabel": "Plan Name [Axis]"
       }
      }
     },
     "localname": "PlanNameAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSDefinedContributionPlanNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PlanNameDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Plan name for share-based payment arrangement.",
        "label": "Plan Name [Domain]",
        "terseLabel": "Plan Name [Domain]"
       }
      }
     },
     "localname": "PlanNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSDefinedContributionPlanNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PortionAtFairValueFairValueDisclosureMember": {
     "auth_ref": [
      "r767"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measured at fair value for financial reporting purposes.",
        "label": "Portion at Fair Value Measurement [Member]",
        "terseLabel": "Portion at Fair Value Measurement"
       }
      }
     },
     "localname": "PortionAtFairValueFairValueDisclosureMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PostemploymentBenefitsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Postemployment Benefits [Abstract]",
        "terseLabel": "Postemployment Benefits [Abstract]"
       }
      }
     },
     "localname": "PostemploymentBenefitsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_PreferredStockDividendRatePerDollarAmount": {
     "auth_ref": [
      "r464"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount per share used to calculated dividend payments on preferred stock.",
        "label": "Preferred Stock, Dividend Rate, Per-Dollar-Amount",
        "terseLabel": "Preferred stock, dividend rate, per-dollar-amount (in dollars per share)"
       }
      }
     },
     "localname": "PreferredStockDividendRatePerDollarAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_PreferredStockDividendRatePercentage": {
     "auth_ref": [
      "r464"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The percentage rate used to calculate dividend payments on preferred stock.",
        "label": "Preferred Stock, Dividend Rate, Percentage",
        "terseLabel": "Preferred stock, dividend rate (as a percentage)"
       }
      }
     },
     "localname": "PreferredStockDividendRatePercentage",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_PreferredStockParOrStatedValuePerShare": {
     "auth_ref": [
      "r31",
      "r463"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.",
        "label": "Preferred Stock, Par or Stated Value Per Share",
        "terseLabel": "Preferred stock, par value (in dollars per share)"
       }
      }
     },
     "localname": "PreferredStockParOrStatedValuePerShare",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONNarrativeDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_PreferredStockRedemptionPricePerShare": {
     "auth_ref": [
      "r462",
      "r480",
      "r482"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The price per share at which the preferred stock of an entity that has priority over common stock in the distribution of dividends and in the event of liquidation of the entity is redeemed or may be called at. The redemption features of this preferred stock are solely within the control of the issuer.",
        "label": "Preferred Stock, Redemption Price Per Share",
        "terseLabel": "Redemption Price Per Share (in dollars per share)"
       }
      }
     },
     "localname": "PreferredStockRedemptionPricePerShare",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_PreferredStockSharesAuthorized": {
     "auth_ref": [
      "r31"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.",
        "label": "Preferred Stock, Shares Authorized",
        "terseLabel": "Preferred stock, shares authorized (in shares)"
       }
      }
     },
     "localname": "PreferredStockSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockSharesOutstanding": {
     "auth_ref": [
      "r31"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.",
        "label": "Preferred Stock, Shares Outstanding",
        "terseLabel": "Shares outstanding (in shares)"
       }
      }
     },
     "localname": "PreferredStockSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockTextBlock": {
     "auth_ref": [
      "r490"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for terms, amounts, nature of changes, rights and privileges, dividends, and other matters related to preferred stock.",
        "label": "Preferred Stock [Text Block]",
        "terseLabel": "PREFERRED STOCK NOT SUBJECT TO MANDATORY REDEMPTION"
       }
      }
     },
     "localname": "PreferredStockTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTION"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_PreferredStockValueOutstanding": {
     "auth_ref": [
      "r31"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Value of all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by shareholders, which is net of related treasury stock. May be all or a portion of the number of preferred shares authorized. These shares represent the ownership interest of the preferred shareholders.",
        "label": "Preferred Stock, Value, Outstanding",
        "terseLabel": "Preferred stock value outstanding"
       }
      }
     },
     "localname": "PreferredStockValueOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Primary financial statement caption encompassing prepaid expenses and other current assets.",
        "label": "Prepaid Expenses and Other Current Assets [Member]",
        "terseLabel": "Current Derivative Assets",
        "verboseLabel": "Special Deposits"
       }
      }
     },
     "localname": "PrepaidExpensesAndOtherCurrentAssetsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSScheduleofGrossFairValueofContractsDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PrepaidTaxes": {
     "auth_ref": [
      "r15",
      "r17",
      "r337",
      "r338"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 10.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of asset related to consideration paid in advance for income and other taxes that provide economic benefits within a future period of one year or the normal operating cycle, if longer.",
        "label": "Prepaid Taxes",
        "terseLabel": "Prepaid Property Taxes"
       }
      }
     },
     "localname": "PrepaidTaxes",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PrivateEquityFundsMember": {
     "auth_ref": [
      "r542"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Investments held in private equity funds.",
        "label": "Private Equity Funds [Member]",
        "terseLabel": "Private Equity",
        "verboseLabel": "Private Equity"
       }
      }
     },
     "localname": "PrivateEquityFundsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ProceedsFromContributionsFromParent": {
     "auth_ref": [
      "r137"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 8.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow from parent as a source of financing that is recorded as additional paid in capital.",
        "label": "Proceeds from Contributions from Parent",
        "terseLabel": "Capital Contributions from Eversource Parent"
       }
      }
     },
     "localname": "ProceedsFromContributionsFromParent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromCustomers": {
     "auth_ref": [
      "r146"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cash receipts from customers during the current period which are usually for sales of goods and services.",
        "label": "Proceeds from Customers",
        "terseLabel": "Refund payments"
       }
      }
     },
     "localname": "ProceedsFromCustomers",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESFERCROEComplaintsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromDivestitureOfBusinessesAndInterestsInAffiliates": {
     "auth_ref": [
      "r129"
     ],
     "calculation": {
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow associated with the amount received from the sale of a business segment or subsidiary or sale of an entity that is related to it but not strictly controlled during the period (for example, an unconsolidated subsidiary, affiliate, joint venture or equity method investment).",
        "label": "Proceeds from Divestiture of Businesses and Interests in Affiliates",
        "terseLabel": "Return of Capital from Subsidiaries"
       }
      }
     },
     "localname": "ProceedsFromDivestitureOfBusinessesAndInterestsInAffiliates",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromIssuanceOfCommonStock": {
     "auth_ref": [
      "r135"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow from the additional capital contribution to the entity.",
        "label": "Proceeds from Issuance of Common Stock",
        "terseLabel": "Issuance of Common Shares, Net of Issuance Costs",
        "verboseLabel": "Net proceeds from common shares issued directly by the Company"
       }
      }
     },
     "localname": "ProceedsFromIssuanceOfCommonStock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromIssuanceOfDebt": {
     "auth_ref": [
      "r136"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.",
        "label": "Proceeds from Issuance of Debt",
        "terseLabel": "Issuance"
       }
      }
     },
     "localname": "ProceedsFromIssuanceOfDebt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromIssuanceOfLongTermDebt": {
     "auth_ref": [
      "r136"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 7.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.",
        "label": "Proceeds from Issuance of Long-term Debt",
        "terseLabel": "Issuance of Long-Term Debt",
        "verboseLabel": "Issuance of Long-Term Debt"
       }
      }
     },
     "localname": "ProceedsFromIssuanceOfLongTermDebt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromLegalSettlements": {
     "auth_ref": [
      "r147"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 10.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cash received for the settlement of litigation during the current period.",
        "label": "Proceeds from Legal Settlements",
        "terseLabel": "Proceeds from DOE Spent Nuclear Fuel Litigation"
       }
      }
     },
     "localname": "ProceedsFromLegalSettlements",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromPaymentsForOtherFinancingActivities": {
     "auth_ref": [
      "r137",
      "r140"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 10.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow (outflow) from financing activities classified as other.",
        "label": "Proceeds from (Payments for) Other Financing Activities",
        "terseLabel": "Other Financing Activities",
        "verboseLabel": "Other Financing Activities"
       }
      }
     },
     "localname": "ProceedsFromPaymentsForOtherFinancingActivities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow associated with the aggregate amount received by the entity through sale or maturity of marketable securities  (held-to-maturity or available-for-sale) during the period.",
        "label": "Proceeds from Sale and Maturity of Marketable Securities",
        "terseLabel": "Proceeds from Sales of Marketable Securities"
       }
      }
     },
     "localname": "ProceedsFromSaleAndMaturityOfMarketableSecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment": {
     "auth_ref": [
      "r130"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale.",
        "label": "Proceeds from Sale of Property, Plant, and Equipment",
        "netLabel": "Proceeds from the sale of Hingham Water System",
        "terseLabel": "Proceeds from the Sale of Generation Assets"
       }
      }
     },
     "localname": "ProceedsFromSaleOfPropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromShortTermDebt": {
     "auth_ref": [
      "r136"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow from a borrowing having initial term of repayment within one year or the normal operating cycle, if longer.",
        "label": "Proceeds from Short-term Debt",
        "terseLabel": "(Decrease)/Increase in Notes Payable"
       }
      }
     },
     "localname": "ProceedsFromShortTermDebt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProfitLoss": {
     "auth_ref": [
      "r12",
      "r100",
      "r103",
      "r109",
      "r143",
      "r166",
      "r190",
      "r202",
      "r203",
      "r242",
      "r248",
      "r252",
      "r255",
      "r258",
      "r308",
      "r414",
      "r415",
      "r416",
      "r419",
      "r420",
      "r421",
      "r423",
      "r425",
      "r427",
      "r428",
      "r700",
      "r705",
      "r707",
      "r717",
      "r718",
      "r752",
      "r772",
      "r883"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.",
        "label": "Net Income (Loss), Including Portion Attributable to Noncontrolling Interest",
        "terseLabel": "Net income attributable to noncontrolling interests"
       }
      }
     },
     "localname": "ProfitLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHAREHOLDERSEQUITYANDNONCONTROLLINGINTERESTSDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PropertyLeaseGuaranteeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A guarantee of performance by a third party lessee under terms of a lease agreement.",
        "label": "Property Lease Guarantee [Member]",
        "terseLabel": "Lease Payments for Real Estate"
       }
      }
     },
     "localname": "PropertyLeaseGuaranteeMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Property, Plant and Equipment [Abstract]",
        "terseLabel": "Property, Plant and Equipment [Abstract]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentByTypeAxis": {
     "auth_ref": [
      "r47",
      "r353"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of long-lived, physical assets used to produce goods and services and not intended for resale.",
        "label": "Long-Lived Tangible Asset [Axis]",
        "terseLabel": "Property, Plant and Equipment, Type [Axis]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentByTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock": {
     "auth_ref": [
      "r359",
      "r934",
      "r935",
      "r936"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for long-lived, physical asset used in normal conduct of business and not intended for resale. Includes, but is not limited to, work of art, historical treasure, and similar asset classified as collections.",
        "label": "Property, Plant and Equipment Disclosure [Text Block]",
        "terseLabel": "PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATION"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Property, Plant and Equipment [Line Items]",
        "terseLabel": "Property, Plant and Equipment [Line Items]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAggregateCompositeDepreciationRatesDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentTypeDomain": {
     "auth_ref": [
      "r25",
      "r352"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Listing of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.",
        "label": "Long-Lived Tangible Asset [Domain]",
        "terseLabel": "Property, Plant and Equipment, Type [Domain]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentUsefulLife": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.",
        "label": "Property, Plant and Equipment, Useful Life",
        "terseLabel": "Estimated useful life of property, plant and equipment"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentUsefulLife",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_ProvisionForDoubtfulAccounts": {
     "auth_ref": [
      "r121",
      "r320"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of expense (reversal of expense) for expected credit loss on accounts receivable.",
        "label": "Accounts Receivable, Credit Loss Expense (Reversal)",
        "terseLabel": "Uncollectible Expense",
        "verboseLabel": "Uncollectible Expense"
       }
      }
     },
     "localname": "ProvisionForDoubtfulAccounts",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity": {
     "auth_ref": [
      "r960",
      "r961"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The component of the allowance for funds used during construction during the period based on an assumed rate of return on equity funds used in financing the construction of regulated assets.",
        "label": "Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity",
        "terseLabel": "Equity Funds"
       }
      }
     },
     "localname": "PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAFUDCandWeightedAverageAFUDCDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedInterest": {
     "auth_ref": [
      "r960"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount capitalized of allowance for funds used during construction.",
        "label": "Allowance for Funds Used During Construction, Capitalized Interest",
        "terseLabel": "Borrowed Funds"
       }
      }
     },
     "localname": "PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedInterest",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAFUDCandWeightedAverageAFUDCDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionRate": {
     "auth_ref": [
      "r960",
      "r961"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Effective rate, including composite rate, of cost of financing additions to qualifying regulated assets, commonly called allowance for funds used during construction.",
        "label": "Public Utilities, Allowance for Funds Used During Construction, Rate",
        "terseLabel": "Average AFUDC Rate"
       }
      }
     },
     "localname": "PublicUtilitiesAllowanceForFundsUsedDuringConstructionRate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofAFUDCandWeightedAverageAFUDCDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_PublicUtilitiesAmountOfAllowanceForEarningsOnEquityCapitalizedForRateMakingPurposes": {
     "auth_ref": [
      "r954"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Discloses the amount of any allowance for earnings on shareholders' investment capitalized for rate making purposes but not for the financial statements.",
        "label": "Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes",
        "terseLabel": "Equity return not recorded on the balance sheet"
       }
      }
     },
     "localname": "PublicUtilitiesAmountOfAllowanceForEarningsOnEquityCapitalizedForRateMakingPurposes",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PublicUtilitiesDisclosureTextBlock": {
     "auth_ref": [
      "r962"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for public utilities.",
        "label": "Public Utilities Disclosure [Text Block]",
        "terseLabel": "REGULATORY ACCOUNTING"
       }
      }
     },
     "localname": "PublicUtilitiesDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTING"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_PublicUtilitiesInventoryFuelMember": {
     "auth_ref": [
      "r43"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Any material consumed to produce energy.",
        "label": "Public Utilities, Inventory, Fuel [Member]",
        "verboseLabel": "Fuel"
       }
      }
     },
     "localname": "PublicUtilitiesInventoryFuelMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PublicUtilitiesInventoryLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Public Utilities, Inventory [Line Items]",
        "terseLabel": "Public Utilities, Inventory [Line Items]"
       }
      }
     },
     "localname": "PublicUtilitiesInventoryLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PublicUtilitiesInventoryTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Detailed information about the type of inventory held by the utility and the carrying value of this inventory.",
        "label": "Public Utilities, Inventory [Table]",
        "terseLabel": "Public Utilities, Inventory [Table]"
       }
      }
     },
     "localname": "PublicUtilitiesInventoryTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESFuelMaterialsSuppliesandInventoryDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails": {
       "order": 2.0,
       "parentTag": "es_PropertyPlantAndEquipmentNetExcludingConstructionWorkInProgress",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period end book value of accumulated depreciation on property, plant and equipment (PPE) that is owned by the regulated operations of the public utility.",
        "label": "Public Utilities, Property, Plant and Equipment, Accumulated Depreciation",
        "negatedTotalLabel": "Total Accumulated Depreciation"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period end amount of construction work in progress in public utility.",
        "label": "Public Utilities, Property, Plant and Equipment, Construction Work in Progress",
        "terseLabel": "Construction Work in Progress"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Composite depreciation rate for public utility plants in service.",
        "label": "Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service",
        "terseLabel": "Composite depreciation rate for plant in service"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAggregateCompositeDepreciationRatesDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentDistribution": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails": {
       "order": 1.0,
       "parentTag": "es_PublicUtilitiesPropertyPlantAndEquipmentElectricNaturalGasandWaterUtilityTotal",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period end amount of property, plant and equipment (PPE) related to utility distribution.",
        "label": "Public Utilities, Property, Plant and Equipment, Distribution",
        "terseLabel": "Distribution - Electric"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantAndEquipmentDistribution",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentGenerationOrProcessing": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails": {
       "order": 5.0,
       "parentTag": "es_PublicUtilitiesPropertyPlantAndEquipmentElectricNaturalGasandWaterUtilityTotal",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period end amount of property, plant and equipment (PPE) related to generation or processing owned by public utility.",
        "label": "Public Utilities, Property, Plant and Equipment, Generation or Processing",
        "terseLabel": "Solar"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantAndEquipmentGenerationOrProcessing",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 2.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      },
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period end amount of total net PPE.",
        "label": "Public Utilities, Property, Plant and Equipment, Net",
        "terseLabel": "Property, Plant and Equipment, Net",
        "totalLabel": "Total Property, Plant and Equipment, Net"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantAndEquipmentNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNetAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Public Utilities, Property, Plant and Equipment, Net [Abstract]",
        "terseLabel": "Less: \u00a0Accumulated Depreciation"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantAndEquipmentNetAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentOtherPropertyPlantAndEquipment": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period end book value of other property, plant and equipment (PPE) owned (but not classified elsewhere) by the public utility.",
        "label": "Public Utilities, Property, Plant and Equipment, Other Property, Plant and Equipment",
        "verboseLabel": "Other"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantAndEquipmentOtherPropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails": {
       "order": 1.0,
       "parentTag": "es_PropertyPlantAndEquipmentNetExcludingConstructionWorkInProgress",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period end amount of total gross PPE.",
        "label": "Public Utilities, Property, Plant and Equipment, Plant in Service",
        "totalLabel": "Property, Plant and Equipment, Gross"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantAndEquipmentPlantInService",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PublicUtilitiesPropertyPlantAndEquipmentTransmission": {
     "auth_ref": [],
     "calculation": {
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails": {
       "order": 3.0,
       "parentTag": "es_PublicUtilitiesPropertyPlantAndEquipmentElectricNaturalGasandWaterUtilityTotal",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period end amount of property, plant and equipment (PPE) related to utility transmission owned by public utility.",
        "label": "Public Utilities, Property, Plant and Equipment, Transmission",
        "terseLabel": "Transmission - Electric"
       }
      }
     },
     "localname": "PublicUtilitiesPropertyPlantAndEquipmentTransmission",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RatioOfIndebtednessToNetCapital1": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indebtedness divided by net capital.",
        "label": "Ratio of Indebtedness to Net Capital",
        "terseLabel": "Consolidated total debt to total capital ratio (as a percentage)"
       }
      }
     },
     "localname": "RatioOfIndebtednessToNetCapital1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DIVIDENDRESTRICTIONSDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_RealEstateMember": {
     "auth_ref": [
      "r502"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Property consisting of land, land improvement and buildings.",
        "label": "Real Estate [Member]",
        "terseLabel": "Real Assets"
       }
      }
     },
     "localname": "RealEstateMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofLongtermRatesofReturnonPensionandPBOPDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ReceivableTypeDomain": {
     "auth_ref": [
      "r66"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financing arrangement representing a contractual right to receive money either on demand or on fixed and determinable dates.",
        "label": "Receivable [Domain]",
        "terseLabel": "Receivable [Domain]"
       }
      }
     },
     "localname": "ReceivableTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ReceivablesFromCustomers": {
     "auth_ref": [
      "r863"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 3.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount due from customers for fees and charges arising from transactions related to the entity's brokerage activities and operations.",
        "label": "Receivables from Customers",
        "terseLabel": "Unbilled Revenues"
       }
      }
     },
     "localname": "ReceivablesFromCustomers",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ReceivablesPolicyTextBlock": {
     "auth_ref": [
      "r270",
      "r273",
      "r274",
      "r275"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy for receivable. Includes, but is not limited to, accounts receivable and financing receivable.",
        "label": "Receivable [Policy Text Block]",
        "terseLabel": "Provision for Uncollectible Accounts"
       }
      }
     },
     "localname": "ReceivablesPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]",
        "terseLabel": "Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]"
       }
      }
     },
     "localname": "ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSNarrativeDetails",
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax": {
     "auth_ref": [
      "r97",
      "r107",
      "r108",
      "r782",
      "r786",
      "r788"
     ],
     "calculation": {
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount before tax of reclassification adjustments of other comprehensive income (loss).",
        "label": "Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax",
        "negatedTerseLabel": "Reclassifications from AOCI"
       }
      }
     },
     "localname": "ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax": {
     "auth_ref": [
      "r97",
      "r107",
      "r108",
      "r110",
      "r782",
      "r786",
      "r788"
     ],
     "calculation": {
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after tax of reclassification adjustments of other comprehensive income (loss).",
        "label": "Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax",
        "negatedTotalLabel": "Total Amounts Reclassified from AOCI, Net of Tax"
       }
      }
     },
     "localname": "ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]",
        "terseLabel": "AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]"
       }
      }
     },
     "localname": "ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTaxAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent": {
     "auth_ref": [
      "r97",
      "r110"
     ],
     "calculation": {
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after tax of reclassification adjustments of other comprehensive income (loss) attributable to parent.",
        "label": "Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent",
        "negatedTerseLabel": "Amounts Reclassified from AOCI"
       }
      }
     },
     "localname": "ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ReclassificationFromAociCurrentPeriodTax": {
     "auth_ref": [
      "r95",
      "r99",
      "r107"
     ],
     "calculation": {
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income (loss).",
        "label": "Reclassification from AOCI, Current Period, Tax",
        "terseLabel": "Tax Effect"
       }
      }
     },
     "localname": "ReclassificationFromAociCurrentPeriodTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis": {
     "auth_ref": [
      "r109"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by item reclassified out of accumulated other comprehensive income (loss).",
        "label": "Reclassification out of Accumulated Other Comprehensive Income [Axis]",
        "terseLabel": "Reclassification out of Accumulated Other Comprehensive Income [Axis]"
       }
      }
     },
     "localname": "ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain": {
     "auth_ref": [
      "r109"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Item reclassified out of accumulated other comprehensive income (loss).",
        "label": "Reclassification out of Accumulated Other Comprehensive Income [Domain]",
        "terseLabel": "Reclassification out of Accumulated Other Comprehensive Income [Domain]"
       }
      }
     },
     "localname": "ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember": {
     "auth_ref": [
      "r109"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Identifies item reclassified out of accumulated other comprehensive income (loss).",
        "label": "Reclassification out of Accumulated Other Comprehensive Income [Member]",
        "terseLabel": "Reclassification out of Accumulated Other Comprehensive Income"
       }
      }
     },
     "localname": "ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable": {
     "auth_ref": [
      "r109"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about items reclassified out of accumulated other comprehensive income (loss).",
        "label": "Reclassification out of Accumulated Other Comprehensive Income [Table]",
        "terseLabel": "Reclassification out of Accumulated Other Comprehensive Income [Table]"
       }
      }
     },
     "localname": "ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSNarrativeDetails",
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]",
        "terseLabel": "Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]"
       }
      }
     },
     "localname": "ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationofUnrecognizedTaxBenefitDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RecordedUnconditionalPurchaseObligation": {
     "auth_ref": [
      "r381"
     ],
     "calculation": {
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the recorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).",
        "label": "Recorded Unconditional Purchase Obligation",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "RecordedUnconditionalPurchaseObligation",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RecordedUnconditionalPurchaseObligationDueAfterFifthYear": {
     "auth_ref": [
      "r381"
     ],
     "calculation": {
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_RecordedUnconditionalPurchaseObligation",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of recorded unconditional purchase obligation maturing after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Recorded Unconditional Purchase Obligation, to be Paid, after Year Five",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "RecordedUnconditionalPurchaseObligationDueAfterFifthYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RecordedUnconditionalPurchaseObligationDueInFifthYear": {
     "auth_ref": [
      "r381"
     ],
     "calculation": {
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_RecordedUnconditionalPurchaseObligation",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of recorded unconditional purchase obligation to be paid in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Recorded Unconditional Purchase Obligation, to be Paid, Year Five",
        "terseLabel": "2026"
       }
      }
     },
     "localname": "RecordedUnconditionalPurchaseObligationDueInFifthYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RecordedUnconditionalPurchaseObligationDueInFourthYear": {
     "auth_ref": [
      "r381"
     ],
     "calculation": {
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_RecordedUnconditionalPurchaseObligation",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of recorded unconditional purchase obligation to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Recorded Unconditional Purchase Obligation, to be Paid, Year Four",
        "terseLabel": "2025"
       }
      }
     },
     "localname": "RecordedUnconditionalPurchaseObligationDueInFourthYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RecordedUnconditionalPurchaseObligationDueInSecondYear": {
     "auth_ref": [
      "r381"
     ],
     "calculation": {
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_RecordedUnconditionalPurchaseObligation",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of recorded unconditional purchase obligation to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Recorded Unconditional Purchase Obligation, to be Paid, Year Two",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "RecordedUnconditionalPurchaseObligationDueInSecondYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RecordedUnconditionalPurchaseObligationDueInThirdYear": {
     "auth_ref": [
      "r381"
     ],
     "calculation": {
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_RecordedUnconditionalPurchaseObligation",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of recorded unconditional purchase obligation to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Recorded Unconditional Purchase Obligation, to be Paid, Year Three",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "RecordedUnconditionalPurchaseObligationDueInThirdYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RecordedUnconditionalPurchaseObligationDueWithinOneYear": {
     "auth_ref": [
      "r381"
     ],
     "calculation": {
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_RecordedUnconditionalPurchaseObligation",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of recorded unconditional purchase obligation to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Recorded Unconditional Purchase Obligation, to be Paid, Year One",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "RecordedUnconditionalPurchaseObligationDueWithinOneYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RecordedUnconditionalPurchaseObligationPaymentScheduleAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Recorded Unconditional Purchase Obligation, Fiscal Year Maturity Schedule [Abstract]",
        "terseLabel": "Recorded Unconditional Purchase Obligation, Fiscal Year Maturity Schedule [Abstract]"
       }
      }
     },
     "localname": "RecordedUnconditionalPurchaseObligationPaymentScheduleAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount": {
     "auth_ref": [
      "r456",
      "r457",
      "r458",
      "r459"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 5.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "As of the reporting date, the carrying amount of noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. The noncontrolling interest holder's ownership (or holders' ownership) may be in the form of preferred shares (regardless of class), preferred partnership units (regardless of class), preferential membership interests, or any other form of preferred equity regardless of investee entity legal form.",
        "label": "Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount",
        "netLabel": "Noncontrolling interest - preferred stock of subsidiaries",
        "terseLabel": "Preferred Stock Not Subject to Mandatory Redemption",
        "verboseLabel": "Noncontrolling Interest - Preferred Stock of Subsidiaries"
       }
      }
     },
     "localname": "RedeemableNoncontrollingInterestEquityPreferredCarryingAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHAREHOLDERSEQUITYANDNONCONTROLLINGINTERESTSDetails",
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/FAIRVALUEOFFINANCIALINSTRUMENTSFairValueHierarchyDetails",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RegulatedOperationsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Regulated Operations [Abstract]",
        "terseLabel": "Regulated Operations [Abstract]"
       }
      }
     },
     "localname": "RegulatedOperationsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_RegulatoryAgencyAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by name of regulatory agency.",
        "label": "Regulatory Agency [Axis]",
        "terseLabel": "Regulatory Agency [Axis]"
       }
      }
     },
     "localname": "RegulatoryAgencyAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RegulatoryAgencyDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Organization that establishes and ensures compliance with rules or regulations.",
        "label": "Regulatory Agency [Domain]",
        "terseLabel": "Regulatory Agency [Domain]"
       }
      }
     },
     "localname": "RegulatoryAgencyDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RegulatoryAssetAmortizationPeriod": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortization period for the recovery of regulatory asset, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Regulatory Asset, Amortization Period",
        "terseLabel": "Recovery period"
       }
      }
     },
     "localname": "RegulatoryAssetAmortizationPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_RegulatoryAssetAxis": {
     "auth_ref": [
      "r952",
      "r953",
      "r957"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of regulatory asset.",
        "label": "Regulatory Asset [Axis]",
        "terseLabel": "Regulatory Asset [Axis]"
       }
      }
     },
     "localname": "RegulatoryAssetAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RegulatoryAssetDomain": {
     "auth_ref": [
      "r952"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate action of a regulator resulting in capitalization of costs incurred.",
        "label": "Regulatory Asset [Domain]",
        "terseLabel": "Regulatory Asset [Domain]"
       }
      }
     },
     "localname": "RegulatoryAssetDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESOtherIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RegulatoryAssetLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Regulatory Assets [Line Items]",
        "terseLabel": "Regulatory Assets [Line Items]"
       }
      }
     },
     "localname": "RegulatoryAssetLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RegulatoryAssets": {
     "auth_ref": [
      "r952"
     ],
     "calculation": {
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period.",
        "label": "Regulatory Assets",
        "terseLabel": "Securitized Stranded Cost (included in Regulatory Assets)",
        "totalLabel": "Total Regulatory Assets",
        "verboseLabel": "Regulatory assets"
       }
      }
     },
     "localname": "RegulatoryAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RegulatoryAssetsCurrent": {
     "auth_ref": [
      "r952"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 5.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      },
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_RegulatoryAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost.",
        "label": "Regulatory Assets, Current",
        "terseLabel": "Regulatory Assets",
        "verboseLabel": "Less: \u00a0Current Portion"
       }
      }
     },
     "localname": "RegulatoryAssetsCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RegulatoryAssetsNoncurrent": {
     "auth_ref": [
      "r952"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 1.0,
       "parentTag": "us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment",
       "weight": 1.0
      },
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_RegulatoryAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer.",
        "label": "Regulatory Assets, Noncurrent",
        "terseLabel": "Total Long-Term Regulatory Assets",
        "verboseLabel": "Regulatory Assets"
       }
      }
     },
     "localname": "RegulatoryAssetsNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RegulatoryLiabilities": {
     "auth_ref": [
      "r956"
     ],
     "calculation": {
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period.",
        "label": "Regulatory Liabilities",
        "totalLabel": "Total Regulatory Liabilities"
       }
      }
     },
     "localname": "RegulatoryLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RegulatoryLiabilitiesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Regulatory Liabilities [Line Items]",
        "terseLabel": "Regulatory Liabilities [Line Items]"
       }
      }
     },
     "localname": "RegulatoryLiabilitiesLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RegulatoryLiabilityAxis": {
     "auth_ref": [
      "r956"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of regulatory liability.",
        "label": "Regulatory Liability [Axis]",
        "terseLabel": "Regulatory Liability [Axis]"
       }
      }
     },
     "localname": "RegulatoryLiabilityAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RegulatoryLiabilityCurrent": {
     "auth_ref": [
      "r956"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 5.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      },
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_RegulatoryLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount for the individual regulatory current liability as itemized in a table of regulatory current liabilities as of the end of the period.",
        "label": "Regulatory Liability, Current",
        "terseLabel": "Regulatory Liabilities",
        "verboseLabel": "Less: \u00a0Current Portion"
       }
      }
     },
     "localname": "RegulatoryLiabilityCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RegulatoryLiabilityDomain": {
     "auth_ref": [
      "r956"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate action of a regulator resulting in accrual of costs or expenses.",
        "label": "Regulatory Liability [Domain]",
        "terseLabel": "Regulatory Liability [Domain]"
       }
      }
     },
     "localname": "RegulatoryLiabilityDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RegulatoryLiabilityNoncurrent": {
     "auth_ref": [
      "r59"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 2.0,
       "parentTag": "us-gaap_LiabilitiesOtherThanLongtermDebtNoncurrent",
       "weight": 1.0
      },
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_RegulatoryLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period.",
        "label": "Regulatory Liability, Noncurrent",
        "terseLabel": "Regulatory Liabilities",
        "verboseLabel": "Total Long-Term Regulatory Liabilities"
       }
      }
     },
     "localname": "RegulatoryLiabilityNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RepaymentsOfLongTermDebt": {
     "auth_ref": [
      "r139"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 9.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.",
        "label": "Repayments of Long-term Debt",
        "negatedLabel": "Retirement of Long-Term Debt",
        "negatedTerseLabel": "Repayments of debt"
       }
      }
     },
     "localname": "RepaymentsOfLongTermDebt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RepaymentsOfShortTermDebt": {
     "auth_ref": [
      "r139"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash outflow for a borrowing having initial term of repayment within one year or the normal operating cycle, if longer.",
        "label": "Repayments of Short-term Debt",
        "negatedTerseLabel": "(Decrease)/Increase in Notes Payable"
       }
      }
     },
     "localname": "RepaymentsOfShortTermDebt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RestrictedCash": {
     "auth_ref": [
      "r160",
      "r865",
      "r897"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.",
        "label": "Restricted Cash",
        "terseLabel": "Restricted cash"
       }
      }
     },
     "localname": "RestrictedCash",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RestrictedCashAndCashEquivalents": {
     "auth_ref": [
      "r23",
      "r154",
      "r160",
      "r865",
      "r897"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.",
        "label": "Restricted Cash and Cash Equivalents",
        "terseLabel": "Restricted Cash",
        "verboseLabel": "Restricted cash"
       }
      }
     },
     "localname": "RestrictedCashAndCashEquivalents",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RestrictedCashAndCashEquivalentsItemsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Restricted Cash and Cash Equivalents Items [Line Items]",
        "terseLabel": "Restricted Cash and Cash Equivalents Items [Line Items]"
       }
      }
     },
     "localname": "RestrictedCashAndCashEquivalentsItemsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RestrictedStockUnitsRSUMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share instrument which is convertible to stock or an equivalent amount of cash, after a specified period of time or when specified performance conditions are met.",
        "label": "Restricted Stock Units (RSUs) [Member]",
        "terseLabel": "Restricted Stock Units (RSUs)"
       }
      }
     },
     "localname": "RestrictedStockUnitsRSUMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RetainedEarningsAccumulatedDeficit": {
     "auth_ref": [
      "r38",
      "r487",
      "r631",
      "r826",
      "r900",
      "r922",
      "r927"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 3.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cumulative amount of the reporting entity's undistributed earnings or deficit.",
        "label": "Retained Earnings (Accumulated Deficit)",
        "terseLabel": "Retained Earnings",
        "verboseLabel": "Retained Earnings"
       }
      }
     },
     "localname": "RetainedEarningsAccumulatedDeficit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RetainedEarningsMember": {
     "auth_ref": [
      "r2",
      "r186",
      "r187",
      "r188",
      "r191",
      "r200",
      "r203",
      "r314",
      "r628",
      "r629",
      "r630",
      "r666",
      "r667",
      "r750",
      "r918",
      "r920"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cumulative amount of the reporting entity's undistributed earnings or deficit.",
        "label": "Retained Earnings [Member]",
        "terseLabel": "Retained Earnings"
       }
      }
     },
     "localname": "RetainedEarningsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RetainedEarningsUnappropriated": {
     "auth_ref": [
      "r37",
      "r164",
      "r899"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A segregation of retained earnings which is available for dividend distribution. Earnings not paid out as dividends but instead reinvested in the core business or used to pay off debt. Unappropriated profit is part of shareholder equity. Also called cumulative distributions or earned surplus or accumulated earnings or unappropriated profit.",
        "label": "Retained Earnings, Unappropriated",
        "terseLabel": "Retained earnings subject to restrictions"
       }
      }
     },
     "localname": "RetainedEarningsUnappropriated",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DIVIDENDRESTRICTIONSDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RetirementPlanNameAxis": {
     "auth_ref": [
      "r519",
      "r520",
      "r521",
      "r522",
      "r523",
      "r524",
      "r525",
      "r526",
      "r527",
      "r528",
      "r529",
      "r530",
      "r531",
      "r532",
      "r533",
      "r534",
      "r535",
      "r536",
      "r537",
      "r538",
      "r539",
      "r541",
      "r542",
      "r543",
      "r544",
      "r545",
      "r546",
      "r547",
      "r548",
      "r549",
      "r550",
      "r551",
      "r552",
      "r553",
      "r554",
      "r555",
      "r556",
      "r557",
      "r558",
      "r559",
      "r560",
      "r561",
      "r563",
      "r564",
      "r565",
      "r566",
      "r568",
      "r569",
      "r571",
      "r572",
      "r573",
      "r576",
      "r577",
      "r578",
      "r579",
      "r580",
      "r581",
      "r582",
      "r583",
      "r584",
      "r585",
      "r595",
      "r596",
      "r597",
      "r598",
      "r599",
      "r600",
      "r601",
      "r602",
      "r603",
      "r608"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by name of plan designed to provide retirement benefits. Includes, but is not limited to, legal name of defined benefit and defined contribution plans.",
        "label": "Retirement Plan Name [Axis]",
        "terseLabel": "Retirement Plan Name [Axis]"
       }
      }
     },
     "localname": "RetirementPlanNameAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RetirementPlanNameDomain": {
     "auth_ref": [
      "r519",
      "r520",
      "r521",
      "r522",
      "r523",
      "r524",
      "r525",
      "r526",
      "r527",
      "r528",
      "r529",
      "r530",
      "r531",
      "r532",
      "r533",
      "r534",
      "r535",
      "r536",
      "r537",
      "r538",
      "r539",
      "r541",
      "r542",
      "r543",
      "r544",
      "r545",
      "r546",
      "r547",
      "r548",
      "r549",
      "r550",
      "r551",
      "r552",
      "r553",
      "r554",
      "r555",
      "r556",
      "r557",
      "r558",
      "r559",
      "r560",
      "r561",
      "r563",
      "r564",
      "r565",
      "r566",
      "r568",
      "r569",
      "r571",
      "r572",
      "r573",
      "r576",
      "r577",
      "r578",
      "r579",
      "r580",
      "r581",
      "r582",
      "r583",
      "r584",
      "r585",
      "r595",
      "r596",
      "r597",
      "r598",
      "r599",
      "r600",
      "r601",
      "r602",
      "r603",
      "r608"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of plan designed to provide retirement benefits. Includes, but is not limited to, legal name of defined benefit and defined contribution plans.",
        "label": "Retirement Plan Name [Domain]",
        "terseLabel": "Retirement Plan Name [Domain]"
       }
      }
     },
     "localname": "RetirementPlanNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RetirementPlanTypeAxis": {
     "auth_ref": [
      "r513",
      "r514",
      "r516",
      "r519",
      "r520",
      "r521",
      "r522",
      "r523",
      "r524",
      "r525",
      "r526",
      "r527",
      "r528",
      "r529",
      "r530",
      "r531",
      "r532",
      "r533",
      "r534",
      "r535",
      "r536",
      "r537",
      "r538",
      "r539",
      "r541",
      "r542",
      "r543",
      "r544",
      "r545",
      "r546",
      "r547",
      "r548",
      "r549",
      "r550",
      "r551",
      "r552",
      "r553",
      "r554",
      "r555",
      "r556",
      "r557",
      "r558",
      "r559",
      "r560",
      "r561",
      "r563",
      "r565",
      "r566",
      "r568",
      "r569",
      "r571",
      "r576",
      "r577",
      "r578",
      "r579",
      "r580",
      "r581",
      "r582",
      "r583",
      "r584",
      "r585",
      "r586",
      "r587",
      "r589",
      "r590",
      "r591",
      "r592",
      "r593",
      "r594",
      "r604",
      "r605",
      "r606",
      "r607"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of retirement benefit plan. Includes, but is not limited to, retirement benefit arrangement for defined benefit pension and other postretirement plans, retirement benefit arrangement for defined contribution pension and other postretirement plans, and special and contractual termination benefits payable upon retirement.",
        "label": "Retirement Plan Type [Axis]",
        "terseLabel": "Retirement Plan Type [Axis]"
       }
      }
     },
     "localname": "RetirementPlanTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssumptionsusedToCalculatePensionandSERPandPBOPDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofEstimatedFutureBenefitPaymentsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofFundedStatusDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RetirementPlanTypeDomain": {
     "auth_ref": [
      "r513",
      "r514",
      "r516",
      "r519",
      "r520",
      "r521",
      "r522",
      "r523",
      "r524",
      "r525",
      "r526",
      "r527",
      "r528",
      "r529",
      "r530",
      "r531",
      "r532",
      "r533",
      "r534",
      "r535",
      "r536",
      "r537",
      "r538",
      "r539",
      "r541",
      "r542",
      "r543",
      "r544",
      "r545",
      "r546",
      "r547",
      "r548",
      "r549",
      "r550",
      "r551",
      "r552",
      "r553",
      "r554",
      "r555",
      "r556",
      "r557",
      "r558",
      "r559",
      "r560",
      "r561",
      "r563",
      "r565",
      "r566",
      "r568",
      "r569",
      "r571",
      "r576",
      "r577",
      "r578",
      "r579",
      "r580",
      "r581",
      "r582",
      "r583",
      "r584",
      "r585",
      "r586",
      "r587",
      "r589",
      "r590",
      "r591",
      "r592",
      "r593",
      "r594",
      "r604",
      "r605",
      "r606",
      "r607"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Type of plan designed to provide participants with retirement benefits. Includes, but is not limited to, retirement benefit arrangement for defined benefit pension and other postretirement plans, retirement benefit arrangement for defined contribution pension and other postretirement plans, and special and contractual termination benefits payable upon retirement.",
        "label": "Retirement Plan Type [Domain]",
        "terseLabel": "Retirement Plan Type [Domain]"
       }
      }
     },
     "localname": "RetirementPlanTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSPensionPlanNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssetCategoryDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssumptionsusedToCalculatePensionandSERPandPBOPDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofEstimatedFutureBenefitPaymentsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofFundedStatusDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofPensionBenefitObligationsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Revenue from Contract with Customer [Abstract]",
        "terseLabel": "Revenue from Contract with Customer [Abstract]"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax": {
     "auth_ref": [
      "r233",
      "r234",
      "r247",
      "r253",
      "r254",
      "r261",
      "r262",
      "r265",
      "r499",
      "r500",
      "r862"
     ],
     "calculation": {
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_Revenues",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.",
        "label": "Revenue from Contract with Customer, Including Assessed Tax",
        "verboseLabel": "Revenues from Contracts with Customers"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerIncludingAssessedTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESNarrativeDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerTextBlock": {
     "auth_ref": [
      "r491",
      "r492",
      "r493",
      "r494",
      "r495",
      "r496",
      "r497",
      "r498",
      "r501",
      "r509"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.",
        "label": "Revenue from Contract with Customer [Text Block]",
        "terseLabel": "REVENUES"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUES"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_RevenueNotFromContractWithCustomer": {
     "auth_ref": [
      "r113"
     ],
     "calculation": {
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_Revenues",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of revenue that is not accounted for under Topic 606.",
        "label": "Revenue Not from Contract with Customer",
        "terseLabel": "Alternative Revenue Programs"
       }
      }
     },
     "localname": "RevenueNotFromContractWithCustomer",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RevenueNotFromContractWithCustomerOther": {
     "auth_ref": [
      "r112"
     ],
     "calculation": {
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_Revenues",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of revenue that is not accounted for under Topic 606, classified as other.",
        "label": "Revenue Not from Contract with Customer, Other",
        "terseLabel": "Other Revenues"
       }
      }
     },
     "localname": "RevenueNotFromContractWithCustomerOther",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_Revenues": {
     "auth_ref": [
      "r113",
      "r166",
      "r233",
      "r234",
      "r247",
      "r253",
      "r254",
      "r261",
      "r262",
      "r265",
      "r308",
      "r414",
      "r415",
      "r416",
      "r419",
      "r420",
      "r421",
      "r423",
      "r425",
      "r427",
      "r428",
      "r772",
      "r883"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 1.0,
       "parentTag": "us-gaap_OperatingIncomeLoss",
       "weight": 1.0
      },
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_OperatingIncomeLoss",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).",
        "label": "Revenues",
        "terseLabel": "Operating Revenues",
        "totalLabel": "Operating Revenues",
        "verboseLabel": "Operating Revenues"
       }
      }
     },
     "localname": "Revenues",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability": {
     "auth_ref": [
      "r809",
      "r814"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase in right-of-use asset obtained in exchange for finance lease liability.",
        "label": "Right-of-Use Asset Obtained in Exchange for Finance Lease Liability",
        "terseLabel": "Right-of-use-Assets Obtained in Exchange for New Finance Lease Liabilities"
       }
      }
     },
     "localname": "RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability": {
     "auth_ref": [
      "r809",
      "r814"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase in right-of-use asset obtained in exchange for operating lease liability.",
        "label": "Right-of-Use Asset Obtained in Exchange for Operating Lease Liability",
        "terseLabel": "Right-of-use-Assets Obtained in Exchange for New Operating Lease Liabilities"
       }
      }
     },
     "localname": "RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESNarrativeDetails",
      "http://www.eversource.com/role/LEASESOtherInformationRelatedtoLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.",
        "label": "Sale of Stock, Number of Shares Issued in Transaction",
        "terseLabel": "Equity offering (in shares)"
       }
      }
     },
     "localname": "SaleOfStockNumberOfSharesIssuedInTransaction",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_SaleOfStockPricePerShare": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.",
        "label": "Sale of Stock, Price Per Share",
        "terseLabel": "Price per share (in dollars per share)"
       }
      }
     },
     "localname": "SaleOfStockPricePerShare",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_SalesMember": {
     "auth_ref": [
      "r731"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Primary financial statement caption encompassing revenue from sale of goods and services rendered in the normal course of business.",
        "label": "Sales [Member]",
        "terseLabel": "Sales"
       }
      }
     },
     "localname": "SalesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/REVENUESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable": {
     "auth_ref": [
      "r66"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule itemizing specific types of trade accounts and notes receivable, and for each the gross carrying value, allowance, and net carrying value as of the balance sheet date. Presentation is categorized by current, noncurrent and unclassified receivables.",
        "label": "Schedule of Accounts, Notes, Loans and Financing Receivable [Table]",
        "terseLabel": "Schedule of Accounts, Notes, Loans and Financing Receivable [Table]"
       }
      }
     },
     "localname": "ScheduleOfAccountsNotesLoansAndFinancingReceivableTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESAllowanceforUncollectibleAccountsDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTransferofEnergyEfficiencyLoansDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock": {
     "auth_ref": [
      "r66"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the various types of trade accounts and notes receivable and for each the gross carrying value, allowance, and net carrying value as of the balance sheet date. Presentation is categorized by current, noncurrent and unclassified receivables.",
        "label": "Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]",
        "terseLabel": "Provision for Uncollectible Accounts"
       }
      }
     },
     "localname": "ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock": {
     "auth_ref": [
      "r97",
      "r787",
      "r788"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the components of accumulated other comprehensive income (loss).",
        "label": "Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]",
        "terseLabel": "Changes in Accumulated Other Comprehensive Income/(Loss) by Component, Net of Tax"
       }
      }
     },
     "localname": "ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock": {
     "auth_ref": [
      "r540"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the major categories of plan assets of pension plans and/or other employee benefit plans.  This information may include, but is not limited to, the target allocation of plan assets, the fair value of each major category of plan assets, and the level within the fair value hierarchy in which the fair value measurements fall.",
        "label": "Schedule of Allocation of Plan Assets [Table Text Block]",
        "terseLabel": "Schedule of Allocation of Plan Assets"
       }
      }
     },
     "localname": "ScheduleOfAllocationOfPlanAssetsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfAmountsRecognizedInOtherComprehensiveIncomeLossTableTextBlock": {
     "auth_ref": [
      "r560"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the net gain (loss) and net prior service cost or credit recognized in other comprehensive income (loss) for the period for pension plans and/or other employee benefit plans, and reclassification adjustments of other comprehensive income (loss) for the period, as those amounts, including amortization of the net transition asset or obligation, are recognized as components of net periodic benefit cost.",
        "label": "Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]",
        "terseLabel": "Schedule of Amounts Recognized in Regulatory Assets and OCI"
       }
      }
     },
     "localname": "ScheduleOfAmountsRecognizedInOtherComprehensiveIncomeLossTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfAssumptionsUsedTableTextBlock": {
     "auth_ref": [
      "r562"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of assumption used to determine benefit obligation and net periodic benefit cost of defined benefit plan. Includes, but is not limited to, discount rate, rate of compensation increase, expected long-term rate of return on plan assets and interest crediting rate.",
        "label": "Defined Benefit Plan, Assumptions [Table Text Block]",
        "terseLabel": "Schedule of Assumptions Used"
       }
      }
     },
     "localname": "ScheduleOfAssumptionsUsedTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Debt Securities, Available-for-sale [Line Items]",
        "terseLabel": "Debt Securities, Available-for-sale [Line Items]"
       }
      }
     },
     "localname": "ScheduleOfAvailableForSaleSecuritiesLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESEquitySecuritiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value.",
        "label": "Schedule of Available-for-sale Securities Reconciliation [Table Text Block]",
        "terseLabel": "Schedule of Available-for-sale Securities Reconciliation"
       }
      }
     },
     "localname": "ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfAvailableForSaleSecuritiesTable": {
     "auth_ref": [
      "r285",
      "r290",
      "r294",
      "r295",
      "r296",
      "r297",
      "r885",
      "r886"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.",
        "label": "Schedule of Available-for-sale Securities [Table]",
        "terseLabel": "Schedule of Available-for-sale Securities [Table]"
       }
      }
     },
     "localname": "ScheduleOfAvailableForSaleSecuritiesTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESEquitySecuritiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock": {
     "auth_ref": [
      "r572",
      "r586"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of benefit obligation and plan assets for defined benefit pension plan with projected benefit obligation in excess of plan assets.",
        "label": "Defined Benefit Plan, Plan with Projected Benefit Obligation in Excess of Plan Assets [Table Text Block]",
        "terseLabel": "Schedule of Benefit Obligations in Excess of Fair Value of Plan Assets"
       }
      }
     },
     "localname": "ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable": {
     "auth_ref": [
      "r685",
      "r686"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule reflecting each material business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities.",
        "label": "Schedule of Business Acquisitions, by Acquisition [Table]",
        "terseLabel": "Schedule of Business Acquisitions, by Acquisition [Table]"
       }
      }
     },
     "localname": "ScheduleOfBusinessAcquisitionsByAcquisitionTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSNarrativeDetails",
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSPreliminaryAllocationoftheCashPurchasePriceDetails",
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSScheduleofProFormaInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of supplemental cash flow information for the periods presented.",
        "label": "Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]",
        "terseLabel": "Supplemental Cash Flow Information"
       }
      }
     },
     "localname": "ScheduleOfCashFlowSupplementalDisclosuresTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfChangeInAssetRetirementObligationTableTextBlock": {
     "auth_ref": [
      "r373"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the changes in carrying amount of a liability for asset retirement obligations, for changes such as new obligations, changes in estimates of existing obligations, spending on existing obligations, property dispositions, and foreign currency translation.",
        "label": "Schedule of Change in Asset Retirement Obligation [Table Text Block]",
        "terseLabel": "Schedule of Change in Asset Retirement Obligation"
       }
      }
     },
     "localname": "ScheduleOfChangeInAssetRetirementObligationTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ASSETRETIREMENTOBLIGATIONSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock": {
     "auth_ref": [
      "r620"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of cost recognized for award under share-based payment arrangement by plan. Includes, but is not limited to, related tax benefit.",
        "label": "Share-based Payment Arrangement, Cost by Plan [Table Text Block]",
        "terseLabel": "Summary of Share Transactions"
       }
      }
     },
     "localname": "ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock": {
     "auth_ref": [
      "r664"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the components of income tax expense attributable to continuing operations for each year presented including, but not limited to: current tax expense (benefit), deferred tax expense (benefit), investment tax credits, government grants, the benefits of operating loss carryforwards, tax expense that results from allocating certain tax benefits either directly to contributed capital or to reduce goodwill or other noncurrent intangible assets of an acquired entity, adjustments of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity, and adjustments of the beginning-of-the-year balances of a valuation allowance because of a change in circumstances that causes a change in judgment about the realizability of the related deferred tax asset in future years.",
        "label": "Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]",
        "terseLabel": "Components of Income Tax Expense"
       }
      }
     },
     "localname": "ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock": {
     "auth_ref": [
      "r84"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of components of comprehensive income (loss). Includes, but is not limited to, foreign currency translation adjustments, foreign currency transactions  designated as economic hedges of a net investment in foreign entity, gain (loss) and prior service cost (credit) for pension plans and other postretirement benefit plans.",
        "label": "Comprehensive Income (Loss) [Table Text Block]",
        "terseLabel": "Schedule of Amounts Reclassified from AOCI by Component"
       }
      }
     },
     "localname": "ScheduleOfComprehensiveIncomeLossTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfDebtInstrumentsTextBlock": {
     "auth_ref": [
      "r58",
      "r175",
      "r448",
      "r450",
      "r480",
      "r484",
      "r485",
      "r486",
      "r791",
      "r792",
      "r796",
      "r893"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.",
        "label": "Schedule of Long-term Debt Instruments [Table Text Block]",
        "terseLabel": "Schedule of Issuance and Repayments of Long-Term Debt"
       }
      }
     },
     "localname": "ScheduleOfDebtInstrumentsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfDebtTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of information pertaining to short-term and long-debt instruments or arrangements, including but not limited to identification of terms, features, collateral requirements and other information necessary to a fair presentation.",
        "label": "Schedule of Debt [Table Text Block]",
        "terseLabel": "Schedule of Borrowings Outstanding",
        "verboseLabel": "Schedule of Outstanding Long-Term Debt"
       }
      }
     },
     "localname": "ScheduleOfDebtTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTTables",
      "http://www.eversource.com/role/SHORTTERMDEBTTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfDeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTitleOfIndividualAndByTypeOfDeferredCompensationTextBlock": {
     "auth_ref": [
      "r510",
      "r511"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of arrangements with individual employees that are not equity-based payments or pensions and other postretirement benefits, which are generally employment contracts between the entity and selected officers or key employees containing a promise by the employer to pay certain amounts at designated future dates, usually including a period after retirement, upon compliance with stipulated requirements. This type of arrangement is distinguished from broader based employee benefit plans as it is usually tailored to the employee. Examples may include profit sharing, deferred bonuses or certain split-dollar life insurance arrangements. Disclosure also typically includes the amount of related compensation expense recognized during the reporting period and the carrying amount as of the balance sheet date of the related liability.",
        "label": "Schedule of Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits by Title of Individual and Type of Deferred Compensation [Table Text Block]",
        "terseLabel": "Schedule of Other Retirement Benefits"
       }
      }
     },
     "localname": "ScheduleOfDeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTitleOfIndividualAndByTypeOfDeferredCompensationTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock": {
     "auth_ref": [
      "r655"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the components of net deferred tax asset or liability recognized in an entity's statement of financial position, including the following: the total of all deferred tax liabilities, the total of all deferred tax assets, the total valuation allowance recognized for deferred tax assets.",
        "label": "Schedule of Deferred Tax Assets and Liabilities [Table Text Block]",
        "terseLabel": "Schedule of Accumulated Deferred Income Tax Obligations"
       }
      }
     },
     "localname": "ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable": {
     "auth_ref": [
      "r570",
      "r571",
      "r574",
      "r575",
      "r586"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosures about an individual defined benefit pension plan or an other postretirement defined benefit plan. It may be appropriate to group certain similar plans.  Also includes schedule for fair value of plan assets by major categories of plan assets by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets or liabilities (Level 1), Significant other observable inputs (Level 2), and significant unobservable inputs (Level 3).",
        "label": "Schedule of Defined Benefit Plans Disclosures [Table]",
        "terseLabel": "Schedule of Defined Benefit Plans Disclosures [Table]"
       }
      }
     },
     "localname": "ScheduleOfDefinedBenefitPlansDisclosuresTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofActuarialAssumptionsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofAssumptionsusedToCalculatePensionandSERPandPBOPDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofComponentsofNetPeriodicBenefitCostsDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofFundedStatusDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofChangesinPlanAssetsandBenefitObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTextBlock": {
     "auth_ref": [
      "r570",
      "r571",
      "r574",
      "r575",
      "r586"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of one or more of the entity's defined benefit pension plans or one or more other defined benefit postretirement plans, separately for pension plans and other postretirement benefit plans including the entity's schedule of fair value of plan assets for defined benefit or other postretirement plans.",
        "label": "Schedule of Defined Benefit Plans Disclosures [Table Text Block]",
        "terseLabel": "Schedule of Defined Benefit Plans"
       }
      }
     },
     "localname": "ScheduleOfDefinedBenefitPlansDisclosuresTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock": {
     "auth_ref": [
      "r728"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position.",
        "label": "Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]",
        "terseLabel": "Schedule of Derivative Instruments in Statement of Financial Position, Fair Value"
       }
      }
     },
     "localname": "ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DERIVATIVEINSTRUMENTSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfDividendPaymentRestrictionsTextBlock": {
     "auth_ref": [
      "r928"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure of statutory restrictions on the payment of dividends as prescribed by the National Association of Insurance Commissioners or state regulatory authorities.",
        "label": "Dividend Payment Restrictions [Text Block]",
        "terseLabel": "DIVIDEND RESTRICTIONS"
       }
      }
     },
     "localname": "ScheduleOfDividendPaymentRestrictionsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/DIVIDENDRESTRICTIONS"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock": {
     "auth_ref": [
      "r216"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of an entity's basic and diluted earnings per share calculations, including a reconciliation of numerators and denominators of the basic and diluted per-share computations for income from continuing operations.",
        "label": "Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]",
        "terseLabel": "Components of Basic and Diluted EPS"
       }
      }
     },
     "localname": "ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EARNINGSPERSHARETables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock": {
     "auth_ref": [
      "r640"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the reconciliation using percentage or dollar amounts of the reported amount of income tax expense attributable to continuing operations for the year to the amount of income tax expense that would result from applying domestic federal statutory tax rates to pretax income from continuing operations.",
        "label": "Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]",
        "terseLabel": "Summary of Reconciliation Between Income Tax Expense and Expected Tax"
       }
      }
     },
     "localname": "ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfEnvironmentalLossContingenciesBySiteTextBlock": {
     "auth_ref": [
      "r369",
      "r371",
      "r372",
      "r374",
      "r396"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of environmental loss contingencies by individual site. Does not include loss contingencies that are not environmental in nature.",
        "label": "Schedule of Environmental Loss Contingencies by Site [Table Text Block]",
        "terseLabel": "Schedule of Environmental Loss Contingencies by Site"
       }
      }
     },
     "localname": "ScheduleOfEnvironmentalLossContingenciesBySiteTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfEquityMethodInvestmentsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Schedule of Equity Method Investments [Line Items]",
        "terseLabel": "Schedule of Equity Method Investments [Line Items]"
       }
      }
     },
     "localname": "ScheduleOfEquityMethodInvestmentsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails",
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESSummaryofInvestmentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfEquityMethodInvestmentsTable": {
     "auth_ref": [
      "r12",
      "r166",
      "r307",
      "r308",
      "r772"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Summarization of information required and determined to be disclosed concerning equity method investments in common stock. The summarized information includes: (a) the name of each investee or group of investees for which combined disclosure is appropriate, (2) the percentage ownership of common stock, (3) the difference, if any, between the carrying amount of an investment and the value of the underlying equity in the net assets and the accounting treatment of difference, if any, and (4) the aggregate value of each identified investment based on its quoted market price, if available.",
        "label": "Schedule of Equity Method Investments [Table]",
        "terseLabel": "Schedule of Equity Method Investments [Table]"
       }
      }
     },
     "localname": "ScheduleOfEquityMethodInvestmentsTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESNarrativeDetails",
      "http://www.eversource.com/role/INVESTMENTSINUNCONSOLIDATEDAFFILIATESSummaryofInvestmentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock": {
     "auth_ref": [
      "r550"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of benefits expected to be paid by pension plans and/or other employee benefit plans in each of the next five fiscal years and in the aggregate for the five fiscal years thereafter.",
        "label": "Schedule of Expected Benefit Payments [Table Text Block]",
        "terseLabel": "Schedule of Expected Benefit Payments"
       }
      }
     },
     "localname": "ScheduleOfExpectedBenefitPaymentsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfGoodwillTable": {
     "auth_ref": [
      "r346",
      "r348"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule of goodwill and the changes during the year due to acquisition, sale, impairment or for other reasons.",
        "label": "Schedule of Goodwill [Table]",
        "terseLabel": "Schedule of Goodwill [Table]"
       }
      }
     },
     "localname": "ScheduleOfGoodwillTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/GOODWILLNarrativeDetails",
      "http://www.eversource.com/role/GOODWILLSummaryofGoodwillbyReportableSegmentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfGuaranteeObligationsTable": {
     "auth_ref": [
      "r406"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure about the type or nature of guarantees, for example performance, indemnification, payment and other guarantees, and related information such as term, origin and purpose, triggering event, maximum exposure, and carrying value. Represents the guarantor's disclosures which include the information about each guarantee, or each group of similar guarantees, even if the likelihood of the guarantor's need to make any payments under the guarantee is remote. This excludes disclosures for product warranties.",
        "label": "Schedule of Guarantor Obligations [Table]",
        "terseLabel": "Schedule of Guarantor Obligations [Table]"
       }
      }
     },
     "localname": "ScheduleOfGuaranteeObligationsTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESSpentNuclearFuelObligationsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfGuaranteeObligationsTextBlock": {
     "auth_ref": [
      "r406",
      "r407"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of each guarantee obligation, or each group of similar guarantee obligations, including (a) the nature of the guarantee, including its term, how it arose, and the events or circumstances that would require the guarantor to perform under the guarantee; (b) the maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee; (c) the current carrying amount of the liability, if any, for the guarantor's obligations under the guarantee; and (d) the nature of any recourse provisions under the guarantee, and any assets held either as collateral or by third parties, and any relevant related party disclosure. Excludes disclosures about product warranties.",
        "label": "Schedule of Guarantor Obligations [Table Text Block]",
        "terseLabel": "Schedule of Guarantor Obligations"
       }
      }
     },
     "localname": "ScheduleOfGuaranteeObligationsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock": {
     "auth_ref": [
      "r411"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of maturity and sinking fund requirement for long-term debt.",
        "label": "Schedule of Maturities of Long-term Debt [Table Text Block]",
        "terseLabel": "Schedule of Maturities of Long-Term Debt Outstanding"
       }
      }
     },
     "localname": "ScheduleOfMaturitiesOfLongTermDebtTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfNetBenefitCostsTableTextBlock": {
     "auth_ref": [
      "r552"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments.",
        "label": "Schedule of Net Benefit Costs [Table Text Block]",
        "terseLabel": "Schedule of Net Benefit Costs"
       }
      }
     },
     "localname": "ScheduleOfNetBenefitCostsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfPropertyPlantAndEquipmentTable": {
     "auth_ref": [
      "r47",
      "r353"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, balances by class of assets, depreciation and depletion expense and method used, including composite depreciation, and accumulated deprecation.",
        "label": "Property, Plant and Equipment [Table]",
        "terseLabel": "Property, Plant and Equipment [Table]"
       }
      }
     },
     "localname": "ScheduleOfPropertyPlantAndEquipmentTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONInvestmentinUtilityPropertyPlantandEquipmentByAssetDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONNarrativeDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAggregateCompositeDepreciationRatesDetails",
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONScheduleofAverageRemainingUsefulLivesofDepreciableAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfPublicUtilityPropertyPlantAndEquipmentTextBlock": {
     "auth_ref": [
      "r46",
      "r950"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of public utility physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, balances by class of assets, deprecation expense and method used, including composite depreciation, and accumulated deprecation.",
        "label": "Public Utility Property, Plant, and Equipment [Table Text Block]",
        "terseLabel": "Schedule of Utility Property, Plant and Equipment"
       }
      }
     },
     "localname": "ScheduleOfPublicUtilityPropertyPlantAndEquipmentTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PROPERTYPLANTANDEQUIPMENTANDACCUMULATEDDEPRECIATIONTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock": {
     "auth_ref": [
      "r689"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the amounts recognized as of the acquisition date for each major class of assets acquired and liabilities assumed. May include but not limited to the following: (a) acquired receivables; (b) contingencies recognized at the acquisition date; and (c) the fair value of noncontrolling interests in the acquiree.",
        "label": "Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]",
        "terseLabel": "Preliminary Allocation of the Cash Purchase Price"
       }
      }
     },
     "localname": "ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACQUISITIONOFASSETSOFCOLUMBIAGASOFMASSACHUSETTSTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfRegulatoryAssetsTable": {
     "auth_ref": [
      "r952",
      "r953",
      "r957"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A table of assets that are created when regulatory agencies permit public utilities to defer certain costs that are included in rate-setting to the balance sheet.",
        "label": "Schedule of Regulatory Assets [Table]",
        "terseLabel": "Schedule of Regulatory Assets [Table]"
       }
      }
     },
     "localname": "ScheduleOfRegulatoryAssetsTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfRegulatoryAssetsTextBlock": {
     "auth_ref": [
      "r952",
      "r953",
      "r957"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of assets that are created when regulatory agencies permit public utilities to defer certain costs included in rate-setting to the balance sheet.",
        "label": "Schedule of Regulatory Assets [Table Text Block]",
        "terseLabel": "Components of Regulatory Assets"
       }
      }
     },
     "localname": "ScheduleOfRegulatoryAssetsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfRegulatoryLiabilitiesTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A table of liabilities that are created when regulatory agencies permit public utilities to defer recognition of certain revenues included in rate-setting.",
        "label": "Schedule of Regulatory Liabilities [Table]",
        "terseLabel": "Schedule of Regulatory Liabilities [Table]"
       }
      }
     },
     "localname": "ScheduleOfRegulatoryLiabilitiesTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryLiabilitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfRegulatoryLiabilitiesTextBlock": {
     "auth_ref": [
      "r956"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of regulatory liabilities. Detailed information about liabilities that result from rate actions of a regulator. Rate actions of a regulator can impose a liability on a regulated enterprise resulting in a regulatory liability.",
        "label": "Schedule of Regulatory Liabilities [Table Text Block]",
        "terseLabel": "Components of Regulatory Liabilities"
       }
      }
     },
     "localname": "ScheduleOfRegulatoryLiabilitiesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfRestrictedCashAndCashEquivalentsTable": {
     "auth_ref": [
      "r23",
      "r160",
      "r865",
      "r897"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about cash and cash equivalents restricted as to withdrawal or usage.",
        "label": "Restrictions on Cash and Cash Equivalents [Table]",
        "terseLabel": "Restrictions on Cash and Cash Equivalents [Table]"
       }
      }
     },
     "localname": "ScheduleOfRestrictedCashAndCashEquivalentsTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESScheduleofCashandCashEquivalentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfRestrictedCashAndCashEquivalentsTextBlock": {
     "auth_ref": [
      "r23",
      "r160",
      "r865",
      "r897"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of cash and cash equivalents restricted as to withdrawal or usage.",
        "label": "Restrictions on Cash and Cash Equivalents [Table Text Block]",
        "terseLabel": "Cash and Cash Equivalents as Reported on the Balance Sheet"
       }
      }
     },
     "localname": "ScheduleOfRestrictedCashAndCashEquivalentsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable": {
     "auth_ref": [
      "r242",
      "r245",
      "r251",
      "r346"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A table disclosing the profit or loss and total assets for each reportable segment of the entity. An entity discloses certain information on each reportable segment if the amounts (a) are included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) are otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss.",
        "label": "Schedule of Segment Reporting Information, by Segment [Table]",
        "terseLabel": "Schedule of Segment Reporting Information, by Segment [Table]"
       }
      }
     },
     "localname": "ScheduleOfSegmentReportingInformationBySegmentTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SEGMENTINFORMATIONNarrativeDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock": {
     "auth_ref": [
      "r242",
      "r245",
      "r251",
      "r346"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the profit or loss and total assets for each reportable segment. An entity discloses certain information on each reportable segment if the amounts (a) are included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) are otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss.",
        "label": "Schedule of Segment Reporting Information, by Segment [Table Text Block]",
        "terseLabel": "Summary of Segment Information and Segmented Total Assets"
       }
      }
     },
     "localname": "ScheduleOfSegmentReportingInformationBySegmentTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SEGMENTINFORMATIONTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable": {
     "auth_ref": [
      "r612",
      "r623"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about share-based payment arrangement.",
        "label": "Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]",
        "terseLabel": "Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]"
       }
      }
     },
     "localname": "ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofCompensationExpenseandIncomeTaxBenefitDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfShortTermDebtTable": {
     "auth_ref": [
      "r53"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A table or schedule providing information pertaining to borrowings under which repayment was required in less than twelve months (or normal operating cycle, if longer) after its issuance. It may include: (1) description of the short-term debt arrangement; (2) identification of the lender or type of lender; (3) repayment terms; (4) weighted average interest rate; (5) carrying amount of funds borrowed under the specified short-term debt arrangement as of the balance sheet date and measures of the maximum and average amount outstanding during the period; (6) description of the refinancing of a short-term obligation when that obligation is excluded from current liabilities in the balance sheet; and (7) amount of a short-term obligation that has been excluded from current liabilities in the balance sheet because of a refinancing of the obligation.",
        "label": "Schedule of Short-term Debt [Table]",
        "terseLabel": "Schedule of Short-term Debt [Table]"
       }
      }
     },
     "localname": "ScheduleOfShortTermDebtTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfStockByClassTable": {
     "auth_ref": [
      "r61",
      "r163",
      "r226",
      "r227",
      "r454",
      "r460",
      "r461",
      "r463",
      "r464",
      "r465",
      "r466",
      "r468",
      "r472",
      "r477",
      "r480",
      "r481",
      "r483",
      "r484",
      "r485",
      "r486",
      "r487"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule detailing information related to equity by class of stock. Class of stock includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. It also includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity.",
        "label": "Schedule of Stock by Class [Table]",
        "terseLabel": "Schedule of Stock by Class [Table]"
       }
      }
     },
     "localname": "ScheduleOfStockByClassTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESCommonSharesAuthorizedandIssuedDetails",
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONNarrativeDetails",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfStockByClassTextBlock": {
     "auth_ref": [
      "r30",
      "r31",
      "r32",
      "r455",
      "r460",
      "r461",
      "r480",
      "r481",
      "r483",
      "r484",
      "r485",
      "r486",
      "r487"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of an entity's stock, including par or stated value per share, number and dollar amount of share subscriptions, shares authorized, shares issued, shares outstanding, number and dollar amount of shares held in an employee trust, dividend per share, total dividends, share conversion features, par value plus additional paid in capital, the value of treasury stock and other information necessary to a fair presentation, and EPS information.  Stock by class includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. Includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity. If more than one issue is outstanding, state the title of each issue and the corresponding dollar amount; dollar amount of any shares subscribed but unissued and the deduction of subscriptions receivable there from; number of shares authorized, issued, and outstanding.",
        "label": "Schedule of Stock by Class [Table Text Block]",
        "terseLabel": "Common Shares Authorized and Issued",
        "verboseLabel": "Schedule of Preferred Stock Not Subject to Mandatory Redemption"
       }
      }
     },
     "localname": "ScheduleOfStockByClassTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESTables",
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Debt and Equity Securities, FV-NI [Line Items]",
        "terseLabel": "Debt and Equity Securities, FV-NI [Line Items]"
       }
      }
     },
     "localname": "ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security with change in fair value recognized in net income (FV-NI).",
        "label": "Debt Securities, Trading, and Equity Securities, FV-NI [Table]",
        "terseLabel": "Debt Securities, Trading, and Equity Securities, FV-NI [Table]"
       }
      }
     },
     "localname": "ScheduleOfTradingSecuritiesAndOtherTradingAssetsTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfUtilityInventoryTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of all information related to inventories for utilities.",
        "label": "Schedule of Utility Inventory [Table Text Block]",
        "terseLabel": "Schedule of Utility Inventory"
       }
      }
     },
     "localname": "ScheduleOfUtilityInventoryTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfVariableInterestEntitiesTextBlock": {
     "auth_ref": [
      "r712",
      "r713",
      "r714",
      "r715",
      "r716"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the significant judgments and assumptions made in determining whether a variable interest (as defined) held by the entity requires the variable interest entity (VIE) (as defined) to be consolidated and (or) disclose information about its involvement with the VIE, individually or in aggregate (as applicable); the nature of restrictions, if any, on the consolidated VIE's assets and on the settlement of its liabilities reported by an entity in its statement of financial position, including the carrying amounts of such assets and liabilities; the nature of, and changes in, the risks associated with involvement in the VIE; how involvement with the VIE affects the entity's financial position, financial performance, and cash flows; the lack of recourse if creditors (or beneficial interest holders) of the consolidated VIE have no recourse to the general credit of the primary beneficiary (if applicable); the terms of arrangements, giving consideration to both explicit arrangements and implicit variable interests, if any, that could require the entity to provide financial support to the VIE, including events or circumstances that could expose the entity to a loss; the methodology used by the entity for determining whether or not it is the primary beneficiary of the variable interest entity; the significant factors considered and judgments made in determining that the power to direct the activities of a VIE that most significantly impact the VIE's economic performance are shared (as defined); the carrying amounts and classification of assets and liabilities of the VIE included in the statement of financial position; the entity's maximum exposure to loss, if any, as a result of its involvement with the VIE, including how the maximum exposure is determined and significant sources of the entity's exposure to the VIE; a comparison of the carrying amounts of the assets and liabilities and the entity's maximum exposure to loss; information about any liquidity arrangements, guarantees, and (or) other commitments by third parties that may affect the fair value or risk of the entity's variable interest in the VIE; whether or not the entity has provided financial support or other support (explicitly or implicitly) to the VIE that it was not previously contractually required to provide or whether the entity intends to provide that support, including the type and amount of the support and the primary reasons for providing the support; and supplemental information the entity determines necessary to provide.",
        "label": "Schedule of Variable Interest Entities [Table Text Block]",
        "terseLabel": "Summary of the Impact of Funding on the Balance Sheets and Income Statements"
       }
      }
     },
     "localname": "ScheduleOfVariableInterestEntitiesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SecuredDebtMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Collateralized debt obligation backed by, for example, but not limited to, pledge, mortgage or other lien on the entity's assets.",
        "label": "Secured Debt [Member]",
        "terseLabel": "Secured Debt"
       }
      }
     },
     "localname": "SecuredDebtMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember": {
     "auth_ref": [
      "r737"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fixed rate on U.S. dollar, constant-notional interest rate swap that has its variable-rate leg referenced to Secured Overnight Financing Rate (SOFR) with no additional spread over SOFR on variable-rate leg.",
        "label": "Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]",
        "terseLabel": "Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate"
       }
      }
     },
     "localname": "SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SegmentDomain": {
     "auth_ref": [
      "r229",
      "r233",
      "r234",
      "r235",
      "r236",
      "r237",
      "r238",
      "r239",
      "r240",
      "r241",
      "r242",
      "r243",
      "r244",
      "r247",
      "r248",
      "r249",
      "r250",
      "r252",
      "r253",
      "r254",
      "r255",
      "r256",
      "r258",
      "r265",
      "r376",
      "r377",
      "r911"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Components of an entity that engage in business activities from which they may earn revenue and incur expenses, including transactions with other components of the same entity.",
        "label": "Segments [Domain]",
        "terseLabel": "Segments [Domain]"
       }
      }
     },
     "localname": "SegmentDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/GOODWILLNarrativeDetails",
      "http://www.eversource.com/role/GOODWILLSummaryofGoodwillbyReportableSegmentDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SegmentReportingAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Segment Reporting [Abstract]",
        "terseLabel": "Segment Reporting [Abstract]"
       }
      }
     },
     "localname": "SegmentReportingAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_SegmentReportingDisclosureTextBlock": {
     "auth_ref": [
      "r229",
      "r231",
      "r232",
      "r242",
      "r246",
      "r252",
      "r256",
      "r257",
      "r258",
      "r259",
      "r261",
      "r264",
      "r265",
      "r266"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.",
        "label": "Segment Reporting Disclosure [Text Block]",
        "terseLabel": "SEGMENT INFORMATION"
       }
      }
     },
     "localname": "SegmentReportingDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SEGMENTINFORMATION"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SegmentReportingInformationLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Segment Reporting Information [Line Items]",
        "terseLabel": "Segment Reporting Information [Line Items]"
       }
      }
     },
     "localname": "SegmentReportingInformationLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SEGMENTINFORMATIONNarrativeDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SeniorNotesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Bond that takes priority over other debt securities sold by the issuer. In the event the issuer goes bankrupt, senior debt holders receive priority for (must receive) repayment prior to (relative to) junior and unsecured (general) creditors.",
        "label": "Senior Notes [Member]",
        "terseLabel": "Senior Notes"
       }
      }
     },
     "localname": "SeniorNotesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod": {
     "auth_ref": [
      "r615"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period",
        "negatedTerseLabel": "Forfeited (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r619"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value",
        "verboseLabel": "Forfeited (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod": {
     "auth_ref": [
      "r617"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period",
        "terseLabel": "Granted (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r617"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value",
        "verboseLabel": "Granted (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber": {
     "auth_ref": [
      "r616"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number",
        "terseLabel": "Shares outstanding (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]",
        "terseLabel": "Units"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r616"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value",
        "terseLabel": "Weighted average shares outstanding (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]",
        "terseLabel": "Weighted Average Grant-Date Fair Value"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod": {
     "auth_ref": [
      "r618"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period",
        "terseLabel": "Restricted stock units available (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r618"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value",
        "terseLabel": "Weighted average grant date fair value of restricted stock units (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award [Line Items]",
        "terseLabel": "Share-based Compensation Arrangement by Share-based Payment Award [Line Items]"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSScheduleofCompensationExpenseandIncomeTaxBenefitDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized": {
     "auth_ref": [
      "r613"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of shares authorized for issuance under share-based payment arrangement.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized",
        "terseLabel": "Shares granted in incentive plan (up to) (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant": {
     "auth_ref": [
      "r623"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant",
        "terseLabel": "Shares available for issuance under incentive plan (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain": {
     "auth_ref": [
      "r610",
      "r614"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Award under share-based payment arrangement.",
        "label": "Award Type [Domain]",
        "terseLabel": "Award Type [Domain]"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EMPLOYEEBENEFITSShareBasedPaymentsNarrativeDetails",
      "http://www.eversource.com/role/EMPLOYEEBENEFITSSummaryofRSUandShareTransactionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShortTermDebtLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Short-term Debt [Line Items]",
        "terseLabel": "Short-term Debt [Line Items]"
       }
      }
     },
     "localname": "ShortTermDebtLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShortTermDebtTextBlock": {
     "auth_ref": [
      "r452"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for short-term debt.",
        "label": "Short-term Debt [Text Block]",
        "terseLabel": "SHORT-TERM DEBT"
       }
      }
     },
     "localname": "ShortTermDebtTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBT"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ShortTermDebtTypeAxis": {
     "auth_ref": [
      "r53"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of short-term debt arrangement.",
        "label": "Short-term Debt, Type [Axis]",
        "terseLabel": "Short-term Debt, Type [Axis]"
       }
      }
     },
     "localname": "ShortTermDebtTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTScheduleofDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShortTermDebtTypeDomain": {
     "auth_ref": [
      "r50"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Type of short-term debt arrangement, such as notes, line of credit, commercial paper, asset-based financing, project financing, letter of credit financing.",
        "label": "Short-term Debt, Type [Domain]",
        "terseLabel": "Short-term Debt, Type [Domain]"
       }
      }
     },
     "localname": "ShortTermDebtTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTScheduleofDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShortTermDebtWeightedAverageInterestRate": {
     "auth_ref": [
      "r51"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average interest rate of short-term debt outstanding calculated at point in time.",
        "label": "Short-term Debt, Weighted Average Interest Rate, at Point in Time",
        "verboseLabel": "Weighted-Average Interest Rate (as a percentage)"
       }
      }
     },
     "localname": "ShortTermDebtWeightedAverageInterestRate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SHORTTERMDEBTScheduleofDebtDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_SignificantAccountingPoliciesTextBlock": {
     "auth_ref": [
      "r161",
      "r185"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for all significant accounting policies of the reporting entity.",
        "label": "Significant Accounting Policies [Text Block]",
        "terseLabel": "SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES"
       }
      }
     },
     "localname": "SignificantAccountingPoliciesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SiteContingencyLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Site Contingency [Line Items]",
        "terseLabel": "Site Contingency [Line Items]"
       }
      }
     },
     "localname": "SiteContingencyLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEversourceandNSTARElectricBostonHarborCivilActionDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SiteContingencyLossExposureNotAccruedBestEstimate": {
     "auth_ref": [
      "r368",
      "r370"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Best estimate of the loss exposure for reasonably possible environmental contingencies at an individual site for which no accrual has been recorded.",
        "label": "Site Contingency, Loss Exposure Not Accrued, Best Estimate",
        "terseLabel": "Best estimate of potential remediation costs (up to)"
       }
      }
     },
     "localname": "SiteContingencyLossExposureNotAccruedBestEstimate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEnvironmentalMattersNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SiteContingencyTable": {
     "auth_ref": [
      "r369",
      "r371",
      "r372",
      "r396"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information and financial data about the reasonably possible loss or the recognized and additional reasonably possible loss from an environmental remediation obligation.",
        "label": "Site Contingency [Table]",
        "terseLabel": "Site Contingency [Table]"
       }
      }
     },
     "localname": "SiteContingencyTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESEversourceandNSTARElectricBostonHarborCivilActionDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StateAndLocalJurisdictionMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Designated tax department of a state or local government entitled to levy and collect income taxes from the entity.",
        "label": "State and Local Jurisdiction [Member]",
        "terseLabel": "State and Local Jurisdiction"
       }
      }
     },
     "localname": "StateAndLocalJurisdictionMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails",
      "http://www.eversource.com/role/INCOMETAXESTaxCreditsandLossCarryforwardsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_StatementBusinessSegmentsAxis": {
     "auth_ref": [
      "r9",
      "r229",
      "r233",
      "r234",
      "r235",
      "r236",
      "r237",
      "r238",
      "r239",
      "r240",
      "r241",
      "r242",
      "r243",
      "r244",
      "r247",
      "r248",
      "r249",
      "r250",
      "r252",
      "r253",
      "r254",
      "r255",
      "r256",
      "r258",
      "r265",
      "r346",
      "r357",
      "r376",
      "r377",
      "r911"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by business segments.",
        "label": "Segments [Axis]",
        "terseLabel": "Segments [Axis]"
       }
      }
     },
     "localname": "StatementBusinessSegmentsAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/GOODWILLNarrativeDetails",
      "http://www.eversource.com/role/GOODWILLSummaryofGoodwillbyReportableSegmentDetails",
      "http://www.eversource.com/role/REVENUESOperatingRevenuesDisaggregatedbyRevenueSourceDetails",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementClassOfStockAxis": {
     "auth_ref": [
      "r30",
      "r31",
      "r32",
      "r163",
      "r166",
      "r208",
      "r209",
      "r211",
      "r214",
      "r216",
      "r226",
      "r227",
      "r228",
      "r308",
      "r414",
      "r419",
      "r420",
      "r421",
      "r427",
      "r428",
      "r463",
      "r464",
      "r468",
      "r472",
      "r479",
      "r772",
      "r971"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by the different classes of stock of the entity.",
        "label": "Class of Stock [Axis]",
        "terseLabel": "Class of Stock [Axis]"
       }
      }
     },
     "localname": "StatementClassOfStockAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/PREFERREDSTOCKNOTSUBJECTTOMANDATORYREDEMPTIONScheduleofPreferredStockbyClassDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementEquityComponentsAxis": {
     "auth_ref": [
      "r2",
      "r63",
      "r107",
      "r108",
      "r109",
      "r186",
      "r187",
      "r188",
      "r191",
      "r200",
      "r203",
      "r225",
      "r314",
      "r479",
      "r487",
      "r628",
      "r629",
      "r630",
      "r666",
      "r667",
      "r750",
      "r782",
      "r783",
      "r784",
      "r785",
      "r786",
      "r788",
      "r918",
      "r919",
      "r920",
      "r1011"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by component of equity.",
        "label": "Equity Components [Axis]",
        "terseLabel": "Equity Components [Axis]"
       }
      }
     },
     "localname": "StatementEquityComponentsAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofAmountsReclassifiedFromAOCIByComponentDetails",
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails",
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Statement [Line Items]",
        "terseLabel": "Statement [Line Items]"
       }
      }
     },
     "localname": "StatementLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETSParenthetical_1",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETSParenthetical",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETSParenthetical",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfCashFlowsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Statement of Cash Flows [Abstract]",
        "terseLabel": "Statement of Cash Flows [Abstract]"
       }
      }
     },
     "localname": "StatementOfCashFlowsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfFinancialPositionAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Statement of Financial Position [Abstract]",
        "terseLabel": "Statement of Financial Position [Abstract]"
       }
      }
     },
     "localname": "StatementOfFinancialPositionAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Statement of Comprehensive Income [Abstract]",
        "terseLabel": "Statement of Comprehensive Income [Abstract]"
       }
      }
     },
     "localname": "StatementOfIncomeAndComprehensiveIncomeAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfStockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Statement of Stockholders' Equity [Abstract]",
        "terseLabel": "Common Shareholders' Equity:"
       }
      }
     },
     "localname": "StatementOfStockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementTable": {
     "auth_ref": [
      "r186",
      "r187",
      "r188",
      "r225",
      "r862"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule reflecting a Statement of Income, Statement of Cash Flows, Statement of Financial Position, Statement of Shareholders' Equity and Other Comprehensive Income, or other statement as needed.",
        "label": "Statement [Table]",
        "terseLabel": "Statement [Table]"
       }
      }
     },
     "localname": "StatementTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETSParenthetical_1",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETSParenthetical",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETSParenthetical",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMPREHENSIVEINCOME",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesAcquisitions": {
     "auth_ref": [
      "r31",
      "r32",
      "r487"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of shares of stock issued during the period pursuant to acquisitions.",
        "label": "Stock Issued During Period, Shares, Acquisitions",
        "terseLabel": "Issuance of Treasury Shares for Acquisition of New England Service Company (in shares)"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesAcquisitions",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesNewIssues": {
     "auth_ref": [
      "r31",
      "r32",
      "r479",
      "r487"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of new stock issued during the period.",
        "label": "Stock Issued During Period, Shares, New Issues",
        "terseLabel": "Issuance of Common Shares (in shares)",
        "verboseLabel": "Common shares issued directly by the Company (in shares)"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesNewIssues",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesTreasuryStockReissued": {
     "auth_ref": [
      "r32",
      "r479",
      "r487"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of treasury shares or units reissued. Excludes reissuance of shares or units in treasury for award under share-based payment arrangement.",
        "label": "Stock Issued During Period, Shares, Treasury Stock Reissued",
        "terseLabel": "Issuance of Treasury Shares (in shares)"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesTreasuryStockReissued",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueAcquisitions": {
     "auth_ref": [
      "r63",
      "r479",
      "r487"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Value of stock issued pursuant to acquisitions during the period.",
        "label": "Stock Issued During Period, Value, Acquisitions",
        "terseLabel": "Issuance of Treasury Shares for Acquisition of New England Service Company"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueAcquisitions",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueNewIssues": {
     "auth_ref": [
      "r31",
      "r32",
      "r479",
      "r487"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.",
        "label": "Stock Issued During Period, Value, New Issues",
        "terseLabel": "Issuance of Common Shares"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueNewIssues",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures": {
     "auth_ref": [
      "r479",
      "r487"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Value of stock related to Restricted Stock Awards issued during the period, net of the stock value of such awards forfeited.",
        "label": "Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures",
        "terseLabel": "Long-Term Incentive Plan Activity"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueTreasuryStockReissued": {
     "auth_ref": [
      "r31",
      "r32",
      "r479",
      "r487",
      "r488"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Value of treasury shares or units reissued. Excludes reissuance of shares or units in treasury for award under share-based payment arrangement.",
        "label": "Stock Issued During Period, Value, Treasury Stock Reissued",
        "terseLabel": "Issuance of Treasury Shares"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueTreasuryStockReissued",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockholdersEquity": {
     "auth_ref": [
      "r32",
      "r40",
      "r41",
      "r166",
      "r272",
      "r308",
      "r772",
      "r826"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 6.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.",
        "label": "Stockholders' Equity Attributable to Parent",
        "periodEndLabel": "Ending balance",
        "periodStartLabel": "Beginning balance",
        "terseLabel": "Stockholders' equity",
        "totalLabel": "Common Shareholders' Equity"
       }
      }
     },
     "localname": "StockholdersEquity",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/ACCUMULATEDOTHERCOMPREHENSIVEINCOMELOSSScheduleofChangesinAOCIByComponentDetails",
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFCOMMONSTOCKHOLDERSEQUITY"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Stockholders' Equity Attributable to Parent [Abstract]",
        "terseLabel": "Common Shareholders' Equity:"
       }
      }
     },
     "localname": "StockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYBALANCESHEETS"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StockholdersEquityNoteDisclosureTextBlock": {
     "auth_ref": [
      "r164",
      "r464",
      "r467",
      "r468",
      "r469",
      "r470",
      "r471",
      "r472",
      "r473",
      "r474",
      "r475",
      "r476",
      "r478",
      "r487",
      "r490"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.",
        "label": "Stockholders' Equity Note Disclosure [Text Block]",
        "terseLabel": "COMMON SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS",
        "verboseLabel": "COMMON SHARES"
       }
      }
     },
     "localname": "StockholdersEquityNoteDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHAREHOLDERSEQUITYANDNONCONTROLLINGINTERESTS",
      "http://www.eversource.com/role/COMMONSHARES"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_StrandedCostsMember": {
     "auth_ref": [
      "r828"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Rate action of a regulator resulting in capitalization or accrual of stranded costs.",
        "label": "Stranded Costs [Member]",
        "terseLabel": "Securitized Stranded Costs"
       }
      }
     },
     "localname": "StrandedCostsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGComponentsofRegulatoryAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SubsequentEventMember": {
     "auth_ref": [
      "r789",
      "r827"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Identifies event that occurred after the balance sheet date but before financial statements are issued or available to be issued.",
        "label": "Subsequent Event [Member]",
        "terseLabel": "Subsequent Event"
       }
      }
     },
     "localname": "SubsequentEventMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SubsequentEventTypeAxis": {
     "auth_ref": [
      "r789",
      "r827"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by event that occurred after the balance sheet date but before financial statements are issued or available to be issued.",
        "label": "Subsequent Event Type [Axis]",
        "terseLabel": "Subsequent Event Type [Axis]"
       }
      }
     },
     "localname": "SubsequentEventTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SubsequentEventTypeDomain": {
     "auth_ref": [
      "r789",
      "r827"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Event that occurred after the balance sheet date but before financial statements are issued or available to be issued.",
        "label": "Subsequent Event Type [Domain]",
        "terseLabel": "Subsequent Event Type [Domain]"
       }
      }
     },
     "localname": "SubsequentEventTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SummaryOfIncomeTaxContingenciesTextBlock": {
     "auth_ref": [
      "r643",
      "r650",
      "r652"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure for tax positions taken in the tax returns filed or to be filed for which it is more likely than not that the tax position will not be sustained upon examination by taxing authorities and other income tax contingencies. Includes, but is not limited to, interest and penalties, reconciliation of unrecognized tax benefits, unrecognized tax benefits that would affect the effective tax rate, tax years that remain subject to examination by tax jurisdictions, and information about positions for which it is reasonably possible that amounts unrecognized will significantly change within 12 months.",
        "label": "Summary of Income Tax Contingencies [Table Text Block]",
        "terseLabel": "Summary of Income Tax Contingencies"
       }
      }
     },
     "localname": "SummaryOfIncomeTaxContingenciesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SummaryOfIncomeTaxExaminationsTextBlock": {
     "auth_ref": [
      "r645",
      "r665"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of income tax examinations that an enterprise is currently subject to or that have been completed in the current period typically including a description of the examination, the jurisdiction conducting the examination, the tax year(s) under examination, the likelihood of an unfavorable settlement, the range of possible losses, the liability recorded, the increase or decrease in the liability from the prior period, and any penalties and interest that have been recorded.",
        "label": "Summary of Income Tax Examinations [Table Text Block]",
        "terseLabel": "Summary of Income Tax Examinations"
       }
      }
     },
     "localname": "SummaryOfIncomeTaxExaminationsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SummaryOfOperatingLossCarryforwardsTextBlock": {
     "auth_ref": [
      "r659"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of pertinent information, such as tax authority, amounts, and expiration dates, of net operating loss carryforwards, including an assessment of the likelihood of utilization.",
        "label": "Summary of Operating Loss Carryforwards [Table Text Block]",
        "terseLabel": "Summary of Tax Credits and Loss Carryforwards"
       }
      }
     },
     "localname": "SummaryOfOperatingLossCarryforwardsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SupplementalCashFlowInformationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Supplemental Cash Flow Information [Abstract]",
        "terseLabel": "Supplemental Cash Flow Information:"
       }
      }
     },
     "localname": "SupplementalCashFlowInformationAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTOFCASHFLOWDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SuretyBondMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "An obligation arising from a three-party agreement that legally binds together a principal who needs the bond, an obligee who requires the bond and a surety company that sells the bond.",
        "label": "Surety Bond [Member]",
        "terseLabel": "Surety Bonds"
       }
      }
     },
     "localname": "SuretyBondMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofGuaranteesandIndemnificationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_TangibleAssetImpairmentCharges": {
     "auth_ref": [
      "r8",
      "r354"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS": {
       "order": 11.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      },
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 7.0,
       "parentTag": "us-gaap_OperatingExpenses",
       "weight": 1.0
      },
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_OperatingIncomeLoss",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The charge against earnings resulting from the aggregate write down of tangible assets from their carrying value to their fair value.",
        "label": "Tangible Asset Impairment Charges",
        "negatedTerseLabel": "Impairment of Northern Pass Transmission",
        "terseLabel": "Impairment of Northern Pass Transmission",
        "verboseLabel": "Pre-tax impairment charge"
       }
      }
     },
     "localname": "TangibleAssetImpairmentCharges",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS",
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TaxCreditCarryforwardAmount": {
     "auth_ref": [
      "r658"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.",
        "label": "Tax Credit Carryforward, Amount",
        "terseLabel": "Federal and State Tax Credit"
       }
      }
     },
     "localname": "TaxCreditCarryforwardAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESTaxCreditsandLossCarryforwardsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TaxesExcludingIncomeAndExciseTaxes": {
     "auth_ref": [
      "r120"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 6.0,
       "parentTag": "us-gaap_OperatingExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "All taxes not related to income of the entity or excise or sales taxes levied on the revenue of the entity that are not reported elsewhere. These taxes could include production, real estate, personal property, and pump tax.",
        "label": "Taxes, Miscellaneous",
        "terseLabel": "Taxes Other Than Income Taxes"
       }
      }
     },
     "localname": "TaxesExcludingIncomeAndExciseTaxes",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain": {
     "auth_ref": [
      "r291",
      "r292",
      "r299",
      "r300",
      "r301",
      "r446",
      "r477",
      "r741",
      "r829",
      "r830",
      "r831",
      "r832",
      "r833",
      "r834",
      "r835",
      "r836",
      "r837",
      "r838",
      "r839",
      "r840",
      "r841",
      "r843",
      "r844",
      "r845",
      "r846",
      "r847",
      "r848",
      "r849",
      "r850",
      "r851",
      "r852",
      "r853",
      "r854",
      "r855",
      "r856",
      "r857",
      "r858",
      "r859",
      "r971",
      "r972",
      "r973",
      "r974",
      "r975",
      "r976",
      "r977"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Instrument or contract that imposes a contractual obligation to deliver cash or another financial instrument or to exchange other financial instruments on potentially unfavorable terms and conveys a contractual right to receive cash or another financial instrument or to exchange other financial instruments on potentially favorable terms.",
        "label": "Financial Instruments [Domain]",
        "terseLabel": "Financial Instruments [Domain]"
       }
      }
     },
     "localname": "TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_TreasuryStockMember": {
     "auth_ref": [
      "r62",
      "r488"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Shares of an entity that have been repurchased by the entity. This stock has no voting rights and receives no dividends. Note that treasury stock may be recorded at its total cost or separately as par (or stated) value and additional paid in capital. Classified within stockholders' equity if nonredeemable or redeemable solely at the option of the issuer. Classified within temporary equity if redemption is outside the control of the issuer.",
        "label": "Treasury Stock [Member]",
        "verboseLabel": "Treasury Stock"
       }
      }
     },
     "localname": "TreasuryStockMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFCOMMONSHAREHOLDERSEQUITY"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_TreasuryStockShares": {
     "auth_ref": [
      "r62",
      "r488"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.",
        "label": "Treasury Stock, Shares",
        "terseLabel": "Treasury stock (in shares)"
       }
      }
     },
     "localname": "TreasuryStockShares",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMONSHARESNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_TreasuryStockValue": {
     "auth_ref": [
      "r62",
      "r488",
      "r489"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS": {
       "order": 5.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount allocated to treasury stock. Treasury stock is common and preferred shares of an entity that were issued, repurchased by the entity, and are held in its treasury.",
        "label": "Treasury Stock, Value",
        "negatedLabel": "Treasury Stock"
       }
      }
     },
     "localname": "TreasuryStockValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDBALANCESHEETS",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTBALANCESHEETDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_USGovernmentDebtSecuritiesMember": {
     "auth_ref": [
      "r884"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debt securities issued by the United States government.",
        "label": "US Government Debt Securities [Member]",
        "terseLabel": "U.S. Government Issued Debt Securities (Agency and Treasury)"
       }
      }
     },
     "localname": "USGovernmentDebtSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/MARKETABLESECURITIESFairValueMeasurementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_UnfavorableRegulatoryActionMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A enacted or proposed action, ruling or regulation that is likely to or possibly will have an adverse effect on the entity's financial position or results of operations, excluding tax matters.",
        "label": "Unfavorable Regulatory Action [Member]",
        "terseLabel": "Unfavorable Regulatory Action"
       }
      }
     },
     "localname": "UnfavorableRegulatoryActionMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPComprehensiveSettlementAgreementDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESCLPTropicalStormIsaiasResponseInvestigationDetails",
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/REVENUESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_UnrecognizedTaxBenefits": {
     "auth_ref": [
      "r634",
      "r646"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of unrecognized tax benefits.",
        "label": "Unrecognized Tax Benefits",
        "periodEndLabel": "Ending Balance",
        "periodStartLabel": "Beginning Balance"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefits",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationofUnrecognizedTaxBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions": {
     "auth_ref": [
      "r647"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.",
        "label": "Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions",
        "negatedLabel": "Gross Decreases - Prior Year"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationofUnrecognizedTaxBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions": {
     "auth_ref": [
      "r648"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.",
        "label": "Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions",
        "terseLabel": "Gross Increases - Current Year"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationofUnrecognizedTaxBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions": {
     "auth_ref": [
      "r647"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.",
        "label": "Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions",
        "terseLabel": "Gross Increases - Prior Year"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationofUnrecognizedTaxBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations": {
     "auth_ref": [
      "r649"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.",
        "label": "Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations",
        "negatedTerseLabel": "Lapse of Statute of Limitations"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESReconciliationofUnrecognizedTaxBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecordedUnconditionalPurchaseObligationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]",
        "terseLabel": "Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract]"
       }
      }
     },
     "localname": "UnrecordedUnconditionalPurchaseObligationAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary": {
     "auth_ref": [
      "r379"
     ],
     "calculation": {
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Unrecorded Unconditional Purchase Obligation, to be Paid, Year Five",
        "terseLabel": "2026"
       }
      }
     },
     "localname": "UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary": {
     "auth_ref": [
      "r379"
     ],
     "calculation": {
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Unrecorded Unconditional Purchase Obligation, to be Paid, Year One",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary": {
     "auth_ref": [
      "r379"
     ],
     "calculation": {
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Unrecorded Unconditional Purchase Obligation, to be Paid, Year Four",
        "terseLabel": "2025"
       }
      }
     },
     "localname": "UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary": {
     "auth_ref": [
      "r379"
     ],
     "calculation": {
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Unrecorded Unconditional Purchase Obligation, to be Paid, Year Two",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary": {
     "auth_ref": [
      "r379"
     ],
     "calculation": {
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Unrecorded Unconditional Purchase Obligation, to be Paid, Year Three",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount": {
     "auth_ref": [
      "r379"
     ],
     "calculation": {
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the unrecorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).",
        "label": "Unrecorded Unconditional Purchase Obligation",
        "terseLabel": "Estimated cost of energy purchase contracts",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESLongTermContractualArrangementNarrativeDetails",
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears": {
     "auth_ref": [
      "r379"
     ],
     "calculation": {
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Unrecorded Unconditional Purchase Obligation, to be Paid, after Year Five",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/COMMITMENTSANDCONTINGENCIESScheduleofEstimatedFutureAnnualCostsofLongtermContractualAgreementDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnsecuredDebtMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debt obligation not collateralized by pledge of, mortgage of or other lien on the entity's assets.",
        "label": "Unsecured Debt [Member]",
        "terseLabel": "Unsecured Debt [Member]",
        "verboseLabel": "Unsecured Debt"
       }
      }
     },
     "localname": "UnsecuredDebtMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails",
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofLongTermDebtOutstandingDetails",
      "http://www.eversource.com/role/SHORTTERMDEBTNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_UnusualOrInfrequentItemAxis": {
     "auth_ref": [
      "r127"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by an event or transaction that is unusual in nature or infrequent in occurrence, or both.",
        "label": "Unusual or Infrequent Item, or Both [Axis]",
        "terseLabel": "Unusual or Infrequent Item, or Both [Axis]"
       }
      }
     },
     "localname": "UnusualOrInfrequentItemAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_UnusualOrInfrequentItemDomain": {
     "auth_ref": [
      "r127"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Event or transaction that is unusual in nature or infrequent in occurrence, or both.",
        "label": "Unusual or Infrequent Item, or Both [Domain]",
        "terseLabel": "Unusual or Infrequent Item, or Both [Domain]"
       }
      }
     },
     "localname": "UnusualOrInfrequentItemDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/REGULATORYACCOUNTINGNarrativeDetails",
      "http://www.eversource.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_UtilitiesOperatingExpenseMaintenanceAndOperations": {
     "auth_ref": [
      "r122"
     ],
     "calculation": {
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME": {
       "order": 2.0,
       "parentTag": "us-gaap_OperatingExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of operating expense for routine plant maintenance, repairs and operations of regulated operation.",
        "label": "Utilities Operating Expense, Maintenance and Operations",
        "terseLabel": "Operations and Maintenance",
        "verboseLabel": "Other"
       }
      }
     },
     "localname": "UtilitiesOperatingExpenseMaintenanceAndOperations",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/NSTARELECTRICCOMPANYANDSUBSIDIARYCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/PUBLICSERVICECOMPANYOFNEWHAMPSHIREANDSUBSIDIARIESCONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails",
      "http://www.eversource.com/role/THECONNECTICUTLIGHTANDPOWERCOMPANYSTATEMENTSOFINCOME"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UtilitiesOperatingExpenseOther": {
     "auth_ref": [
      "r122"
     ],
     "calculation": {
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_OperatingIncomeLoss",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of other operating expense of regulated operation.",
        "label": "Utilities Operating Expense, Other",
        "negatedTerseLabel": "Other Operating Expenses"
       }
      }
     },
     "localname": "UtilitiesOperatingExpenseOther",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SEGMENTINFORMATIONScheduleofSegmentInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount": {
     "auth_ref": [
      "r655"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset.",
        "label": "Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount",
        "terseLabel": "Change in valuation allowance"
       }
      }
     },
     "localname": "ValuationAllowanceDeferredTaxAssetChangeInAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/INCOMETAXESNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ValuationAllowancesAndReservesBalance": {
     "auth_ref": [
      "r177",
      "r183"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of valuation and qualifying accounts and reserves.",
        "label": "SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount",
        "periodEndLabel": "Balance at end of period",
        "periodStartLabel": "Balance at beginning of period"
       }
      }
     },
     "localname": "ValuationAllowancesAndReservesBalance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense": {
     "auth_ref": [
      "r180"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase in valuation and qualifying accounts and reserves from charge to cost and expense.",
        "label": "SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense",
        "terseLabel": "Additions, Charged to Costs and Expense"
       }
      }
     },
     "localname": "ValuationAllowancesAndReservesChargedToCostAndExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts": {
     "auth_ref": [
      "r181"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase in valuation and qualifying accounts and reserves from charge to accounts other than cost and expense.",
        "label": "SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Other Account",
        "terseLabel": "Additions, Charged to Other Accounts"
       }
      }
     },
     "localname": "ValuationAllowancesAndReservesChargedToOtherAccounts",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ValuationAllowancesAndReservesDeductions": {
     "auth_ref": [
      "r182"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of decrease in valuation and qualifying accounts and reserves.",
        "label": "SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction",
        "terseLabel": "Deductions"
       }
      }
     },
     "localname": "ValuationAllowancesAndReservesDeductions",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ValuationAllowancesAndReservesDomain": {
     "auth_ref": [
      "r177",
      "r178",
      "r179",
      "r182",
      "r183"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Valuation and qualifying accounts and reserves.",
        "label": "SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain]",
        "terseLabel": "SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain]"
       }
      }
     },
     "localname": "ValuationAllowancesAndReservesDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ValuationAllowancesAndReservesTypeAxis": {
     "auth_ref": [
      "r177",
      "r178",
      "r179",
      "r182",
      "r183"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by valuation and qualifying accounts and reserves.",
        "label": "SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis]",
        "terseLabel": "SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis]"
       }
      }
     },
     "localname": "ValuationAllowancesAndReservesTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSANDRESERVESDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_VariableInterestEntityPrimaryBeneficiaryMember": {
     "auth_ref": [
      "r703",
      "r704",
      "r710",
      "r711",
      "r712"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Variable Interest Entities (VIE) in which the entity has a controlling financial interest (as defined) and of which it is therefore the primary beneficiary. A controlling financial interest is determined based on both: (a) the entity's power to direct activities of the VIE that most significantly impact the VIE's economic performance and (b) the entity's obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE. VIEs of which the entity is the primary beneficiary are included in the consolidated financial statements of the entity.",
        "label": "Variable Interest Entity, Primary Beneficiary [Member]",
        "terseLabel": "Variable Interest Entity, Primary Beneficiary"
       }
      }
     },
     "localname": "VariableInterestEntityPrimaryBeneficiaryMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESBalanceSheetDetails",
      "http://www.eversource.com/role/RATEREDUCTIONBONDSANDVARIABLEINTERESTENTITIESIncomeStatementDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_VariableLeaseCost": {
     "auth_ref": [
      "r807",
      "r814"
     ],
     "calculation": {
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_LeaseCost",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.",
        "label": "Variable Lease, Cost",
        "terseLabel": "Variable Lease Cost"
       }
      }
     },
     "localname": "VariableLeaseCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LEASESComponentsofLeaseCostDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_VariableRateAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of variable rate.",
        "label": "Variable Rate [Axis]",
        "terseLabel": "Variable Rate [Axis]"
       }
      }
     },
     "localname": "VariableRateAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_VariableRateDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Interest rate that fluctuates over time as a result of an underlying benchmark interest rate or index.",
        "label": "Variable Rate [Domain]",
        "terseLabel": "Variable Rate [Domain]"
       }
      }
     },
     "localname": "VariableRateDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/LONGTERMDEBTScheduleofIssuancesandRepaymentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment": {
     "auth_ref": [
      "r216"
     ],
     "calculation": {
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding",
       "weight": 1.0
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.",
        "label": "Weighted Average Number Diluted Shares Outstanding Adjustment",
        "totalLabel": "Dilutive Effect (in shares)"
       }
      }
     },
     "localname": "WeightedAverageNumberDilutedSharesOutstandingAdjustment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]",
        "terseLabel": "Dilutive Effect of:"
       }
      }
     },
     "localname": "WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding": {
     "auth_ref": [
      "r207",
      "r216"
     ],
     "calculation": {
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.",
        "label": "Weighted Average Number of Shares Outstanding, Diluted",
        "terseLabel": "Diluted (in shares)",
        "totalLabel": "Diluted (in shares)"
       }
      }
     },
     "localname": "WeightedAverageNumberOfDilutedSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Weighted Average Number of Shares Outstanding, Diluted [Abstract]",
        "terseLabel": "Weighted Average Common Shares Outstanding:"
       }
      }
     },
     "localname": "WeightedAverageNumberOfSharesOutstandingAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_WeightedAverageNumberOfSharesOutstandingBasic": {
     "auth_ref": [
      "r205",
      "r216"
     ],
     "calculation": {
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding",
       "weight": 1.0
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.",
        "label": "Weighted Average Number of Shares Outstanding, Basic",
        "verboseLabel": "Basic (in shares)"
       }
      }
     },
     "localname": "WeightedAverageNumberOfSharesOutstandingBasic",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/CONSOLIDATEDSTATEMENTSOFINCOME",
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Weighted Average Number of Shares Outstanding Reconciliation [Abstract]",
        "terseLabel": "Weighted Average Common Shares Outstanding:",
        "verboseLabel": "Weighted Average Common Shares Outstanding:"
       }
      }
     },
     "localname": "WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.eversource.com/role/EARNINGSPERSHAREComponentsofBasicandDilutedEPSDetails",
      "http://www.eversource.com/role/SCHEDULEIFINANCIALINFORMATIONOFREGISTRANTSTATEMENTSOFINCOMEDetails"
     ],
     "xbrltype": "stringItemType"
    }
   },
   "unitCount": 17
  }
 },
 "std_ref": {
  "r0": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "105",
   "URI": "http://asc.fasb.org/extlink&oid=124434974&loc=SL124442142-165695"
  },
  "r1": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "105",
   "URI": "http://asc.fasb.org/extlink&oid=124434974&loc=SL124442142-165695"
  },
  "r10": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760"
  },
  "r100": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669619-108580"
  },
  "r1000": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "13",
   "Subparagraph": "(4)(iii)(B)",
   "Subsection": "01"
  },
  "r1001": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "13",
   "Subparagraph": "(4)(iii)(B)",
   "Subsection": "02"
  },
  "r1002": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "13",
   "Subparagraph": "(4)(iii)(C)",
   "Subsection": "02"
  },
  "r1003": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "13",
   "Subparagraph": "(4)(iv)",
   "Subsection": "01"
  },
  "r1004": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "13",
   "Subparagraph": "(4)(iv)",
   "Subsection": "02"
  },
  "r1005": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "(m)",
   "Publisher": "SEC",
   "Section": "4",
   "Subparagraph": "(1)(iii)",
   "Subsection": "08"
  },
  "r1006": {
   "Name": "Securities Act",
   "Number": "230",
   "Publisher": "SEC",
   "Section": "405"
  },
  "r1007": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "848"
  },
  "r1008": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "848"
  },
  "r1009": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)(2)",
   "Topic": "848"
  },
  "r101": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669619-108580"
  },
  "r1010": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)(3)(iii)(01)",
   "Topic": "848"
  },
  "r1011": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)(3)(iii)(03)",
   "Topic": "848"
  },
  "r102": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669619-108580"
  },
  "r103": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669625-108580"
  },
  "r104": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669625-108580"
  },
  "r105": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=d3e557-108580"
  },
  "r106": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124431353&loc=SL116659661-227067"
  },
  "r107": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124431353&loc=SL124442407-227067"
  },
  "r108": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124431353&loc=SL124442411-227067"
  },
  "r109": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124431353&loc=SL124452729-227067"
  },
  "r11": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5C",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(2)",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721675-107760"
  },
  "r110": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124507222&loc=d3e1436-108581"
  },
  "r111": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(210.5-03(11))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r112": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(1)(e))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r113": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(1))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r114": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(12))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r115": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(20))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r116": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(21))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r117": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(23))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r118": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(24))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r119": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(25))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r12": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760"
  },
  "r120": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(4))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r121": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(5))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r122": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.2(b))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r123": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.3)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r124": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.7(b))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r125": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.7)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r126": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.9)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r127": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=114868883&loc=SL114871943-224233"
  },
  "r128": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "220",
   "URI": "http://asc.fasb.org/topic&trid=2134417"
  },
  "r129": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3179-108585"
  },
  "r13": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=124098289&loc=d3e6676-107765"
  },
  "r130": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3179-108585"
  },
  "r131": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3179-108585"
  },
  "r132": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3213-108585"
  },
  "r133": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3213-108585"
  },
  "r134": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3213-108585"
  },
  "r135": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585"
  },
  "r136": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585"
  },
  "r137": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585"
  },
  "r138": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585"
  },
  "r139": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585"
  },
  "r14": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=124098289&loc=d3e6676-107765"
  },
  "r140": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585"
  },
  "r141": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3367-108585"
  },
  "r142": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3367-108585"
  },
  "r143": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3000-108585"
  },
  "r144": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21D",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=SL94080555-108585"
  },
  "r145": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "24",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3521-108585"
  },
  "r146": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3536-108585"
  },
  "r147": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3536-108585"
  },
  "r148": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3536-108585"
  },
  "r149": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3536-108585"
  },
  "r15": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(g)(4)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=124098289&loc=d3e6676-107765"
  },
  "r150": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3536-108585"
  },
  "r151": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585"
  },
  "r152": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585"
  },
  "r153": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585"
  },
  "r154": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3044-108585"
  },
  "r155": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123431023&loc=d3e4273-108586"
  },
  "r156": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123431023&loc=d3e4297-108586"
  },
  "r157": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123431023&loc=d3e4304-108586"
  },
  "r158": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123431023&loc=d3e4313-108586"
  },
  "r159": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123431023&loc=d3e4332-108586"
  },
  "r16": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=124098289&loc=d3e6676-107765"
  },
  "r160": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123431023&loc=SL98516268-108586"
  },
  "r161": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=123372394&loc=d3e18726-107790"
  },
  "r162": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=123372394&loc=d3e18823-107790"
  },
  "r163": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(d))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r164": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(e)(1))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r165": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(f))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r166": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(g)(1)(ii))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r167": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(h)(1)(Note 1))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r168": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(h)(1))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r169": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(h)(2))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r17": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=124098289&loc=d3e6787-107765"
  },
  "r170": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(h))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r171": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(k)(1))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r172": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(m)(1)(iii))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r173": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(m)(2)(ii))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r174": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(n))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r175": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.12-04(a))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e24072-122690"
  },
  "r176": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.12-04(b))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e24072-122690"
  },
  "r177": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.12-09(Column B))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690"
  },
  "r178": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.12-09(Column C(1)))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690"
  },
  "r179": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.12-09(Column C(2)))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690"
  },
  "r18": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=124098289&loc=d3e6801-107765"
  },
  "r180": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.12-09(Column C)(1))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690"
  },
  "r181": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.12-09(Column C)(2))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690"
  },
  "r182": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.12-09(Column D))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690"
  },
  "r183": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.12-09(Column E))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690"
  },
  "r184": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.12-09)",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690"
  },
  "r185": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "235",
   "URI": "http://asc.fasb.org/topic&trid=2122369"
  },
  "r186": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "23",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124436220&loc=d3e21914-107793"
  },
  "r187": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "24",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124436220&loc=d3e21930-107793"
  },
  "r188": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124436220&loc=d3e21711-107793"
  },
  "r189": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124436220&loc=d3e21728-107793"
  },
  "r19": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=124098289&loc=d3e6904-107765"
  },
  "r190": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(2)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794"
  },
  "r191": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(3)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794"
  },
  "r192": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(4)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794"
  },
  "r193": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794"
  },
  "r194": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794"
  },
  "r195": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794"
  },
  "r196": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=SL124452830-107794"
  },
  "r197": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794"
  },
  "r198": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794"
  },
  "r199": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22644-107794"
  },
  "r2": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "105",
   "URI": "http://asc.fasb.org/extlink&oid=124434974&loc=SL124442142-165695"
  },
  "r20": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=124098289&loc=d3e6911-107765"
  },
  "r200": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22644-107794"
  },
  "r201": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22644-107794"
  },
  "r202": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22658-107794"
  },
  "r203": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22663-107794"
  },
  "r204": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 11.M.Q2)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=122038215&loc=d3e31137-122693"
  },
  "r205": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1448-109256"
  },
  "r206": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1377-109256"
  },
  "r207": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1505-109256"
  },
  "r208": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1252-109256"
  },
  "r209": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1278-109256"
  },
  "r21": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=124098289&loc=d3e6935-107765"
  },
  "r210": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "35",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e2366-109256"
  },
  "r211": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "55",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e2626-109256"
  },
  "r212": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=SL5780133-109256"
  },
  "r213": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=SL5780133-109256"
  },
  "r214": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=SL5780133-109256"
  },
  "r215": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1337-109256"
  },
  "r216": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257"
  },
  "r217": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257"
  },
  "r218": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=124432515&loc=d3e3630-109257"
  },
  "r219": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=109243012&loc=SL65017193-207537"
  },
  "r22": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6361739&loc=d3e7789-107766"
  },
  "r220": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125512782&loc=d3e3842-109258"
  },
  "r221": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "52",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125512782&loc=d3e4984-109258"
  },
  "r222": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "260",
   "URI": "http://asc.fasb.org/topic&trid=2144383"
  },
  "r223": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "270",
   "URI": "http://asc.fasb.org/extlink&oid=124437754&loc=d3e543-108305"
  },
  "r224": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "270",
   "URI": "http://asc.fasb.org/extlink&oid=124502072&loc=SL77927221-108306"
  },
  "r225": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "272",
   "URI": "http://asc.fasb.org/extlink&oid=125520817&loc=d3e70191-108054"
  },
  "r226": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "272",
   "URI": "http://asc.fasb.org/extlink&oid=125520817&loc=d3e70229-108054"
  },
  "r227": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "272",
   "URI": "http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055"
  },
  "r228": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "272",
   "URI": "http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055"
  },
  "r229": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8657-108599"
  },
  "r23": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(1))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r230": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "18",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8672-108599"
  },
  "r231": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8721-108599"
  },
  "r232": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8721-108599"
  },
  "r233": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r234": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r235": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r236": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r237": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r238": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r239": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r24": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(11))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r240": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r241": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(j)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r242": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r243": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8813-108599"
  },
  "r244": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8813-108599"
  },
  "r245": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8813-108599"
  },
  "r246": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "26",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8844-108599"
  },
  "r247": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599"
  },
  "r248": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599"
  },
  "r249": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599"
  },
  "r25": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(13))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r250": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599"
  },
  "r251": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599"
  },
  "r252": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "31",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8924-108599"
  },
  "r253": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599"
  },
  "r254": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599"
  },
  "r255": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599"
  },
  "r256": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599"
  },
  "r257": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599"
  },
  "r258": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599"
  },
  "r259": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "34",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8981-108599"
  },
  "r26": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(19))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r260": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8475-108599"
  },
  "r261": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "40",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e9031-108599"
  },
  "r262": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "41",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e9038-108599"
  },
  "r263": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "41",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e9038-108599"
  },
  "r264": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "41",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e9038-108599"
  },
  "r265": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "42",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e9054-108599"
  },
  "r266": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "280",
   "URI": "http://asc.fasb.org/topic&trid=2134510"
  },
  "r267": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=124259787&loc=d3e4647-111522"
  },
  "r268": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522"
  },
  "r269": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=124259787&loc=d3e4531-111522"
  },
  "r27": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(20))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r270": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5033-111524"
  },
  "r271": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5074-111524"
  },
  "r272": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 4.E)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=122038336&loc=d3e74512-122707"
  },
  "r273": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=84159169&loc=d3e10133-111534"
  },
  "r274": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=84159169&loc=d3e10149-111534"
  },
  "r275": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=84159169&loc=d3e10178-111534"
  },
  "r276": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=124402435&loc=SL124402458-218513"
  },
  "r277": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=124402435&loc=SL124402458-218513"
  },
  "r278": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=124260329&loc=d3e26610-111562"
  },
  "r279": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=124260329&loc=d3e26853-111562"
  },
  "r28": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(22))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r280": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563"
  },
  "r281": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(aa)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563"
  },
  "r282": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563"
  },
  "r283": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563"
  },
  "r284": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563"
  },
  "r285": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563"
  },
  "r286": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27198-111563"
  },
  "r287": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27198-111563"
  },
  "r288": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27198-111563"
  },
  "r289": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27198-111563"
  },
  "r29": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(24))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r290": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27198-111563"
  },
  "r291": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r292": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL120269820-111563"
  },
  "r293": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27290-111563"
  },
  "r294": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27290-111563"
  },
  "r295": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27337-111563"
  },
  "r296": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27340-111563"
  },
  "r297": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)-(d)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27357-111563"
  },
  "r298": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "320",
   "URI": "http://asc.fasb.org/topic&trid=2196928"
  },
  "r299": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "321",
   "URI": "http://asc.fasb.org/extlink&oid=123583765&loc=SL75117539-209714"
  },
  "r3": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "105",
   "URI": "http://asc.fasb.org/extlink&oid=124434974&loc=SL124442142-165695"
  },
  "r30": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(27))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r300": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "321",
   "URI": "http://asc.fasb.org/extlink&oid=123583765&loc=SL75117539-209714"
  },
  "r301": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "321",
   "URI": "http://asc.fasb.org/extlink&oid=123583765&loc=SL75117539-209714"
  },
  "r302": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "321",
   "URI": "http://asc.fasb.org/extlink&oid=123583765&loc=SL75117546-209714"
  },
  "r303": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "10",
   "Topic": "323",
   "URI": "http://asc.fasb.org/extlink&oid=124268079&loc=d3e32787-111569"
  },
  "r304": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "323",
   "URI": "http://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570"
  },
  "r305": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "323",
   "URI": "http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571"
  },
  "r306": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(3)",
   "Topic": "323",
   "URI": "http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571"
  },
  "r307": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(b)",
   "Topic": "323",
   "URI": "http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571"
  },
  "r308": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "323",
   "URI": "http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571"
  },
  "r309": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "323",
   "URI": "http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571"
  },
  "r31": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(28))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r310": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "323",
   "URI": "http://asc.fasb.org/topic&trid=2196965"
  },
  "r311": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437"
  },
  "r312": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437"
  },
  "r313": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437"
  },
  "r314": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437"
  },
  "r315": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(e)(3)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437"
  },
  "r316": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(e)(4)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437"
  },
  "r317": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446"
  },
  "r318": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919244-210447"
  },
  "r319": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447"
  },
  "r32": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(29))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r320": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447"
  },
  "r321": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447"
  },
  "r322": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447"
  },
  "r323": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(f)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447"
  },
  "r324": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447"
  },
  "r325": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919253-210447"
  },
  "r326": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447"
  },
  "r327": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447"
  },
  "r328": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454"
  },
  "r329": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455"
  },
  "r33": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(3)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r330": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455"
  },
  "r331": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL82922895-210455"
  },
  "r332": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL82922900-210455"
  },
  "r333": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456"
  },
  "r334": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "330",
   "URI": "http://asc.fasb.org/extlink&oid=116847112&loc=d3e4492-108314"
  },
  "r335": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "330",
   "URI": "http://asc.fasb.org/extlink&oid=116847112&loc=d3e4556-108314"
  },
  "r336": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "330",
   "URI": "http://asc.fasb.org/topic&trid=2126998"
  },
  "r337": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "05",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "340",
   "URI": "http://asc.fasb.org/extlink&oid=123349782&loc=d3e5879-108316"
  },
  "r338": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "340",
   "URI": "http://asc.fasb.org/extlink&oid=6387103&loc=d3e6435-108320"
  },
  "r339": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266"
  },
  "r34": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(3)(a)(2))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r340": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=99380562&loc=d3e13777-109266"
  },
  "r341": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=120320667&loc=SL49117168-202975"
  },
  "r342": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267"
  },
  "r343": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267"
  },
  "r344": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267"
  },
  "r345": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267"
  },
  "r346": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267"
  },
  "r347": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=121556970&loc=d3e13854-109267"
  },
  "r348": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=121556970&loc=d3e13854-109267"
  },
  "r349": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/subtopic&trid=2144439"
  },
  "r35": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(3))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r350": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=123351718&loc=d3e2443-110228"
  },
  "r351": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229"
  },
  "r352": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229"
  },
  "r353": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229"
  },
  "r354": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=109226691&loc=d3e2921-110230"
  },
  "r355": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230"
  },
  "r356": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230"
  },
  "r357": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230"
  },
  "r358": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230"
  },
  "r359": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "360",
   "URI": "http://asc.fasb.org/topic&trid=2155823"
  },
  "r36": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(30)(a)(1))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r360": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "20",
   "Topic": "410",
   "URI": "http://asc.fasb.org/extlink&oid=6392603&loc=d3e7123-110846"
  },
  "r361": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "410",
   "URI": "http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848"
  },
  "r362": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "410",
   "URI": "http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849"
  },
  "r363": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(1)",
   "Topic": "410",
   "URI": "http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849"
  },
  "r364": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(2)",
   "Topic": "410",
   "URI": "http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849"
  },
  "r365": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(3)",
   "Topic": "410",
   "URI": "http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849"
  },
  "r366": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(4)",
   "Topic": "410",
   "URI": "http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849"
  },
  "r367": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "20",
   "Topic": "410",
   "URI": "http://asc.fasb.org/subtopic&trid=2175671"
  },
  "r368": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(c),(d)(2)",
   "Topic": "410",
   "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13237-110859"
  },
  "r369": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(d)",
   "Topic": "410",
   "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13237-110859"
  },
  "r37": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(30)(a)(3)(ii))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r370": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(d)(2)",
   "Topic": "410",
   "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13237-110859"
  },
  "r371": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "410",
   "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13283-110859"
  },
  "r372": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "410",
   "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13296-110859"
  },
  "r373": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "410",
   "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13201-110859"
  },
  "r374": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "410",
   "URI": "http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859"
  },
  "r375": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869"
  },
  "r376": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869"
  },
  "r377": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 5.P.4(d))",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747"
  },
  "r378": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "440",
   "URI": "http://asc.fasb.org/extlink&oid=123406679&loc=d3e25336-109308"
  },
  "r379": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "440",
   "URI": "http://asc.fasb.org/extlink&oid=123406679&loc=d3e25336-109308"
  },
  "r38": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(30)(a)(3))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r380": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "440",
   "URI": "http://asc.fasb.org/extlink&oid=123406679&loc=d3e25336-109308"
  },
  "r381": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "440",
   "URI": "http://asc.fasb.org/extlink&oid=123406679&loc=d3e25383-109308"
  },
  "r382": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "440",
   "URI": "http://asc.fasb.org/topic&trid=2144648"
  },
  "r383": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=6395460&loc=d3e13647-108346"
  },
  "r384": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349"
  },
  "r385": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14615-108349"
  },
  "r386": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14394-108349"
  },
  "r387": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349"
  },
  "r388": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349"
  },
  "r389": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349"
  },
  "r39": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(30)(a)(4))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r390": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14453-108349"
  },
  "r391": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14472-108349"
  },
  "r392": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14557-108349"
  },
  "r393": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14557-108349"
  },
  "r394": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14557-108349"
  },
  "r395": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "20",
   "Subparagraph": "(SAB TOPIC 5.Y.Q1)",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751"
  },
  "r396": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "20",
   "Subparagraph": "(SAB TOPIC 5.Y.Q2)",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751"
  },
  "r397": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "450",
   "URI": "http://asc.fasb.org/topic&trid=2127136"
  },
  "r398": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "15",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=123389529&loc=d3e10037-110241"
  },
  "r399": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "15",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=123389529&loc=d3e10037-110241"
  },
  "r4": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "105",
   "URI": "http://asc.fasb.org/extlink&oid=124434974&loc=SL124442142-165695"
  },
  "r40": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(30))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r400": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "15",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=123389529&loc=d3e10037-110241"
  },
  "r401": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=124440162&loc=d3e12021-110248"
  },
  "r402": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=124440162&loc=d3e12053-110248"
  },
  "r403": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=124440162&loc=d3e12069-110248"
  },
  "r404": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(1)",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=124440162&loc=d3e12069-110248"
  },
  "r405": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=124440162&loc=d3e12069-110248"
  },
  "r406": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=124440162&loc=d3e12069-110248"
  },
  "r407": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=124440162&loc=d3e12265-110248"
  },
  "r408": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=123408193&loc=d3e13051-110250"
  },
  "r409": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=123408193&loc=d3e12803-110250"
  },
  "r41": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(31))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r410": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=99376301&loc=SL5988623-112600"
  },
  "r411": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123465755&loc=d3e1835-112601"
  },
  "r412": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123465755&loc=SL6230698-112601"
  },
  "r413": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S65",
   "SubTopic": "10",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359872&loc=SL124427846-239511"
  },
  "r414": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-01(a)(4)(i))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756"
  },
  "r415": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-01(a)(4)(ii))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756"
  },
  "r416": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-01(a)(4)(iii)(A))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756"
  },
  "r417": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-01(a)(4)(iii)(B))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756"
  },
  "r418": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-01(a)(4)(iii))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756"
  },
  "r419": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-01(a)(4)(iv))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756"
  },
  "r42": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(32))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r420": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-01(a)(5))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756"
  },
  "r421": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-02(a)(4)(i))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756"
  },
  "r422": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-02(a)(4)(iii)(A)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756"
  },
  "r423": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-02(a)(4)(iii)(A))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756"
  },
  "r424": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-02(a)(4)(iii)(B)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756"
  },
  "r425": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-02(a)(4)(iii)(B))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756"
  },
  "r426": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-02(a)(4)(iii)(C))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756"
  },
  "r427": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-02(a)(4)(iv))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756"
  },
  "r428": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-02(a)(5))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756"
  },
  "r429": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611"
  },
  "r43": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(6)(a))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r430": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611"
  },
  "r431": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611"
  },
  "r432": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611"
  },
  "r433": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611"
  },
  "r434": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(f)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611"
  },
  "r435": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(h)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611"
  },
  "r436": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611"
  },
  "r437": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611"
  },
  "r438": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611"
  },
  "r439": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1E",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611"
  },
  "r44": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.1)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r440": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1E",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611"
  },
  "r441": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1E",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611"
  },
  "r442": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1F",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495355-112611"
  },
  "r443": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1F",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495355-112611"
  },
  "r444": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1F",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(1)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495355-112611"
  },
  "r445": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1F",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(2)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495355-112611"
  },
  "r446": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1I",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611"
  },
  "r447": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(3)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466204&loc=SL6031897-161870"
  },
  "r448": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "69B",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612"
  },
  "r449": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "69C",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612"
  },
  "r45": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.12)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r450": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "69E",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466577&loc=SL123495743-112612"
  },
  "r451": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "69F",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466577&loc=SL123495745-112612"
  },
  "r452": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "470",
   "URI": "http://asc.fasb.org/topic&trid=2208564"
  },
  "r453": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)(1)",
   "Topic": "480",
   "URI": "http://asc.fasb.org/extlink&oid=109262807&loc=d3e22047-110879"
  },
  "r454": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(CFRR 211.02)",
   "Topic": "480",
   "URI": "http://asc.fasb.org/extlink&oid=122040564&loc=d3e177068-122764"
  },
  "r455": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Topic": "480",
   "URI": "http://asc.fasb.org/extlink&oid=122040564&loc=d3e177068-122764"
  },
  "r456": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(12)(c)",
   "Topic": "480",
   "URI": "http://asc.fasb.org/extlink&oid=122040564&loc=SL6540498-122764"
  },
  "r457": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(16)(c)",
   "Topic": "480",
   "URI": "http://asc.fasb.org/extlink&oid=122040564&loc=SL6540498-122764"
  },
  "r458": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "14",
   "Topic": "480",
   "URI": "http://asc.fasb.org/extlink&oid=122040564&loc=SL6540498-122764"
  },
  "r459": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "15",
   "Topic": "480",
   "URI": "http://asc.fasb.org/extlink&oid=122040564&loc=SL6540498-122764"
  },
  "r46": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.13(b))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r460": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=65888546&loc=d3e21300-112643"
  },
  "r461": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=d3e21553-112644"
  },
  "r462": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=d3e21564-112644"
  },
  "r463": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644"
  },
  "r464": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644"
  },
  "r465": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644"
  },
  "r466": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644"
  },
  "r467": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644"
  },
  "r468": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644"
  },
  "r469": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(i)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644"
  },
  "r47": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.14)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r470": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644"
  },
  "r471": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644"
  },
  "r472": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644"
  },
  "r473": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496171-112644"
  },
  "r474": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496180-112644"
  },
  "r475": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "18",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644"
  },
  "r476": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "18",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644"
  },
  "r477": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "18",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644"
  },
  "r478": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "18",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644"
  },
  "r479": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=d3e21463-112644"
  },
  "r48": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.17)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r480": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=d3e21475-112644"
  },
  "r481": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=d3e21484-112644"
  },
  "r482": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=d3e21488-112644"
  },
  "r483": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=d3e21488-112644"
  },
  "r484": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=d3e21506-112644"
  },
  "r485": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=d3e21521-112644"
  },
  "r486": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=d3e21538-112644"
  },
  "r487": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.3-04)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770"
  },
  "r488": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655"
  },
  "r489": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=6405834&loc=d3e23315-112656"
  },
  "r49": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19(a)(5))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r490": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "505",
   "URI": "http://asc.fasb.org/topic&trid=2208762"
  },
  "r491": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130551-203045"
  },
  "r492": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045"
  },
  "r493": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045"
  },
  "r494": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045"
  },
  "r495": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045"
  },
  "r496": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045"
  },
  "r497": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(2)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130556-203045"
  },
  "r498": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130558-203045"
  },
  "r499": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130543-203045"
  },
  "r5": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-04(Schedule I))",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=120391182&loc=d3e5864-122674"
  },
  "r50": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19(a))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r500": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130545-203045"
  },
  "r501": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130550-203045"
  },
  "r502": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123410239&loc=SL49130690-203046-203046"
  },
  "r503": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123410239&loc=SL49130690-203046-203046"
  },
  "r504": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123410239&loc=SL49130690-203046-203046"
  },
  "r505": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123410239&loc=SL49130690-203046-203046"
  },
  "r506": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123410239&loc=SL49130690-203046-203046"
  },
  "r507": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123410239&loc=SL49130690-203046-203046"
  },
  "r508": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123410239&loc=SL49130690-203046-203046"
  },
  "r509": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "606",
   "URI": "http://asc.fasb.org/topic&trid=49130388"
  },
  "r51": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19(b))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r510": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "10",
   "Topic": "710",
   "URI": "http://asc.fasb.org/extlink&oid=6409733&loc=d3e19524-108361"
  },
  "r511": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "30",
   "SubTopic": "10",
   "Topic": "710",
   "URI": "http://asc.fasb.org/extlink&oid=6409875&loc=d3e20015-108363"
  },
  "r512": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "710",
   "URI": "http://asc.fasb.org/topic&trid=2127225"
  },
  "r513": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "15",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "712",
   "URI": "http://asc.fasb.org/extlink&oid=6410066&loc=d3e79218-111664"
  },
  "r514": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "15",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "712",
   "URI": "http://asc.fasb.org/extlink&oid=6410066&loc=d3e79218-111664"
  },
  "r515": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "712",
   "URI": "http://asc.fasb.org/topic&trid=2197446"
  },
  "r516": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123453770&loc=d3e1703-114919"
  },
  "r517": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123453770&loc=d3e1731-114919"
  },
  "r518": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123453770&loc=SL108413299-114919"
  },
  "r519": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r52": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19(b),22(b))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r520": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(1)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r521": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(10)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r522": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(2)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r523": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(3)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r524": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(4)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r525": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(5)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r526": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(6)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r527": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(7)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r528": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(8)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r529": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(9)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r53": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r530": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r531": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(1)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r532": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(2)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r533": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(3)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r534": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(4)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r535": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(5)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r536": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(6)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r537": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(7)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r538": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(8)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r539": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r54": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19,20)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r540": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(5)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r541": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(i)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r542": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(ii)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r543": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(01)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r544": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(02)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r545": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(02)(A)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r546": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(02)(B)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r547": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(02)(C)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r548": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(03)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r549": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r55": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.20)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r550": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(f)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r551": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r552": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(h)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r553": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(h)(1)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r554": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(h)(2)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r555": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(h)(3)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r556": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(h)(4)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r557": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(h)(5)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r558": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(h)(6)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r559": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(h)(7)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r56": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.21)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r560": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(i)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r561": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(j)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r562": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(k)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r563": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(k)(1)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r564": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(k)(2)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r565": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(k)(3)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r566": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(k)(4)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r567": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(l)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r568": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(n)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r569": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(q)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r57": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.22(a)(1))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r570": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r571": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2410-114920"
  },
  "r572": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2417-114920"
  },
  "r573": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2417-114920"
  },
  "r574": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2417-114920"
  },
  "r575": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2439-114920"
  },
  "r576": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920"
  },
  "r577": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(1)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920"
  },
  "r578": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(2)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920"
  },
  "r579": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(3)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920"
  },
  "r58": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.22)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r580": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(4)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920"
  },
  "r581": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(5)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920"
  },
  "r582": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(6)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920"
  },
  "r583": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(7)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920"
  },
  "r584": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920"
  },
  "r585": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e2919-114920"
  },
  "r586": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921"
  },
  "r587": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "18",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123450688&loc=d3e4587-114921"
  },
  "r588": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "60",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=6414203&loc=d3e39716-114964"
  },
  "r589": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "70",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942"
  },
  "r59": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.24)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r590": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "80",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=29639808&loc=d3e29008-114946"
  },
  "r591": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(a)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450702-114947"
  },
  "r592": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(b)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450702-114947"
  },
  "r593": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(c)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450702-114947"
  },
  "r594": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450702-114947"
  },
  "r595": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(a)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947"
  },
  "r596": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(b)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947"
  },
  "r597": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(c)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947"
  },
  "r598": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(d)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947"
  },
  "r599": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(e)(1)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947"
  },
  "r6": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222160&loc=d3e1107-107759"
  },
  "r60": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.25)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r600": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(e)(2)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947"
  },
  "r601": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(f)(1)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947"
  },
  "r602": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(f)(2)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947"
  },
  "r603": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(f)(3)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947"
  },
  "r604": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(a)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450673-114947"
  },
  "r605": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(b)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450673-114947"
  },
  "r606": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(c)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450673-114947"
  },
  "r607": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(b)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450691-114947"
  },
  "r608": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "80",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=35742348&loc=SL14450788-114948"
  },
  "r609": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "715",
   "URI": "http://asc.fasb.org/topic&trid=2235017"
  },
  "r61": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.28,29)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r610": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901"
  },
  "r611": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901"
  },
  "r612": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901"
  },
  "r613": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(3)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r614": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a),(g)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r615": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(iv)(3)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r616": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(i)-(ii)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r617": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(iii)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r618": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(iii)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r619": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(iii)(3)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r62": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.29,30)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r620": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r621": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)(1)(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r622": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r623": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r624": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r625": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r626": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r627": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r628": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r629": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(f)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r63": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.29-31)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r630": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(f)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r631": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(g)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r632": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 14.F)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=122041274&loc=d3e301413-122809"
  },
  "r633": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "718",
   "URI": "http://asc.fasb.org/topic&trid=2228938"
  },
  "r634": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123427490&loc=SL37586934-109318"
  },
  "r635": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123427490&loc=d3e32247-109318"
  },
  "r636": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123427490&loc=d3e32280-109318"
  },
  "r637": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123427490&loc=d3e31917-109318"
  },
  "r638": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123427490&loc=d3e31931-109318"
  },
  "r639": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32672-109319"
  },
  "r64": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.3(a)(2))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r640": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32687-109319"
  },
  "r641": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32705-109319"
  },
  "r642": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32718-109319"
  },
  "r643": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32718-109319"
  },
  "r644": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32718-109319"
  },
  "r645": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32718-109319"
  },
  "r646": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=SL6600010-109319"
  },
  "r647": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=SL6600010-109319"
  },
  "r648": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(2)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=SL6600010-109319"
  },
  "r649": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(4)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=SL6600010-109319"
  },
  "r65": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.3(a)(4))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r650": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=SL6600010-109319"
  },
  "r651": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32809-109319"
  },
  "r652": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "19",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32840-109319"
  },
  "r653": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32537-109319"
  },
  "r654": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32537-109319"
  },
  "r655": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32537-109319"
  },
  "r656": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32847-109319"
  },
  "r657": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32857-109319"
  },
  "r658": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32559-109319"
  },
  "r659": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32559-109319"
  },
  "r66": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.3,4)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r660": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32621-109319"
  },
  "r661": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32632-109319"
  },
  "r662": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32639-109319"
  },
  "r663": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32639-109319"
  },
  "r664": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32639-109319"
  },
  "r665": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "217",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=124434304&loc=d3e36027-109320"
  },
  "r666": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)(2)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123459177&loc=SL121830611-158277"
  },
  "r667": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)(3)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123459177&loc=SL121830611-158277"
  },
  "r668": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB TOPIC 6.I.5.Q1)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817"
  },
  "r669": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB TOPIC 6.I.7)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817"
  },
  "r67": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.6(a)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r670": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 6.I.7)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817"
  },
  "r671": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 6.I.Fact.1)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817"
  },
  "r672": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 6.I.Fact.2)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817"
  },
  "r673": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 6.I.Fact.3)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817"
  },
  "r674": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 11.C)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=122134291&loc=d3e330215-122817"
  },
  "r675": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123586238&loc=d3e38679-109324"
  },
  "r676": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "270",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=6424409&loc=d3e44925-109338"
  },
  "r677": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=6424122&loc=d3e41874-109331"
  },
  "r678": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "740",
   "URI": "http://asc.fasb.org/topic&trid=2144680"
  },
  "r679": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "10",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=123586518&loc=d3e961-128460"
  },
  "r68": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.6(a)(4),(5))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r680": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463"
  },
  "r681": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)(3)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463"
  },
  "r682": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463"
  },
  "r683": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)(2)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463"
  },
  "r684": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)(3)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463"
  },
  "r685": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463"
  },
  "r686": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=79982066&loc=d3e1486-128463"
  },
  "r687": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "37",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=123455525&loc=d3e2207-128464"
  },
  "r688": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=123413009&loc=d3e4845-128472"
  },
  "r689": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=123413009&loc=d3e4845-128472"
  },
  "r69": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.6(a))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r690": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "30",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476"
  },
  "r691": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "30",
   "SubTopic": "30",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=116859721&loc=d3e6578-128477"
  },
  "r692": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "30",
   "SubTopic": "30",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=116859721&loc=d3e6613-128477"
  },
  "r693": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "30",
   "Subparagraph": "(b)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=116859824&loc=d3e6819-128478"
  },
  "r694": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(b)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479"
  },
  "r695": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(b)(1)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479"
  },
  "r696": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(c)(1)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479"
  },
  "r697": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479"
  },
  "r698": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "805",
   "URI": "http://asc.fasb.org/topic&trid=2303972"
  },
  "r699": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=123454820&loc=d3e5283-111683"
  },
  "r7": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222160&loc=SL51721533-107759"
  },
  "r70": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.6(b))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r700": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "19",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=123454820&loc=SL4569616-111683"
  },
  "r701": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=123454820&loc=SL4569643-111683"
  },
  "r702": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=123454820&loc=SL4613674-111683"
  },
  "r703": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116870748&loc=SL6758485-165988"
  },
  "r704": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116870748&loc=SL6758485-165988"
  },
  "r705": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684"
  },
  "r706": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(2)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684"
  },
  "r707": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684"
  },
  "r708": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(3)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684"
  },
  "r709": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c),(3)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684"
  },
  "r71": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.8)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r710": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bb)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=123419778&loc=d3e5710-111685"
  },
  "r711": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=123419778&loc=d3e5710-111685"
  },
  "r712": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=123419778&loc=d3e5710-111685"
  },
  "r713": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=123419778&loc=d3e5728-111685"
  },
  "r714": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=123419778&loc=SL6759159-111685"
  },
  "r715": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=123419778&loc=d3e5747-111685"
  },
  "r716": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=123419778&loc=SL6228884-111685"
  },
  "r717": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4J",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=120409616&loc=SL4591551-111686"
  },
  "r718": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4K",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=120409616&loc=SL4591552-111686"
  },
  "r719": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5579240-113959"
  },
  "r72": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.9)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r720": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959"
  },
  "r721": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=d3e41620-113959"
  },
  "r722": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=d3e41638-113959"
  },
  "r723": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5618551-113959"
  },
  "r724": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5618551-113959"
  },
  "r725": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a),(c)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959"
  },
  "r726": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959"
  },
  "r727": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959"
  },
  "r728": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959"
  },
  "r729": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4C",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624171-113959"
  },
  "r73": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312"
  },
  "r730": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624177-113959"
  },
  "r731": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624177-113959"
  },
  "r732": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624177-113959"
  },
  "r733": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=d3e41675-113959"
  },
  "r734": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=d3e41678-113959"
  },
  "r735": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 5.DD)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=116879480&loc=d3e417888-122833"
  },
  "r736": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=116879480&loc=d3e417888-122833"
  },
  "r737": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6A",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "20",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=124256753&loc=SL5864739-113975"
  },
  "r738": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(c)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=121549185&loc=d3e80748-113994"
  },
  "r739": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Subparagraph": "(a)(1)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123477628&loc=d3e90205-114008"
  },
  "r74": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312"
  },
  "r740": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Subparagraph": "(b)(2)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123477628&loc=d3e90205-114008"
  },
  "r741": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Subparagraph": "(f)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123477628&loc=d3e90205-114008"
  },
  "r742": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(a)(1)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r743": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(a)(2)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r744": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(a)(3)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r745": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(b)(1)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r746": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(b)(2)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r747": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(c)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r748": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(d)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r749": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(e)(2)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r75": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312"
  },
  "r750": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(e)(3)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r751": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(e)(4)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r752": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(f)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r753": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "815",
   "URI": "http://asc.fasb.org/topic&trid=2229140"
  },
  "r754": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r755": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r756": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bb)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r757": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bbb)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r758": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bbb)(2)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r759": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r76": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313"
  },
  "r760": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r761": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r762": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19279-110258"
  },
  "r763": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19279-110258"
  },
  "r764": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=SL6742756-110258"
  },
  "r765": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "60",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=7493716&loc=d3e21868-110260"
  },
  "r766": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123594786&loc=SL75136599-209740"
  },
  "r767": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123594809&loc=d3e13220-108610"
  },
  "r768": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123594938&loc=d3e13279-108611"
  },
  "r769": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611"
  },
  "r77": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226024-175313"
  },
  "r770": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123594938&loc=d3e13467-108611"
  },
  "r771": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123594938&loc=d3e13476-108611"
  },
  "r772": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612"
  },
  "r773": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL120254526-165497"
  },
  "r774": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL120254526-165497"
  },
  "r775": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL121967933-165497"
  },
  "r776": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL121967933-165497"
  },
  "r777": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL121967933-165497"
  },
  "r778": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL121967933-165497"
  },
  "r779": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL122642865-165497"
  },
  "r78": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226038-175313"
  },
  "r780": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL122642865-165497"
  },
  "r781": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "230",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=123444420&loc=d3e33268-110906"
  },
  "r782": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32136-110900"
  },
  "r783": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Subparagraph": "(a)",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r784": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Subparagraph": "(b)",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r785": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Subparagraph": "(c)",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r786": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Subparagraph": "(d)",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r787": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r788": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=6450520&loc=d3e32583-110901"
  },
  "r789": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=6450520&loc=d3e32618-110901"
  },
  "r79": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226049-175313"
  },
  "r790": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391"
  },
  "r791": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=124435984&loc=d3e28541-108399"
  },
  "r792": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399"
  },
  "r793": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=124435984&loc=d3e28555-108399"
  },
  "r794": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=124435984&loc=d3e28567-108399"
  },
  "r795": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629"
  },
  "r796": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400"
  },
  "r797": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123391704&loc=SL77918627-209977"
  },
  "r798": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123391704&loc=SL77918627-209977"
  },
  "r799": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123391704&loc=SL77918631-209977"
  },
  "r8": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=d3e1361-107760"
  },
  "r80": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313"
  },
  "r800": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123391704&loc=SL77918638-209977"
  },
  "r801": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123391704&loc=SL77918643-209977"
  },
  "r802": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123391704&loc=SL77918643-209977"
  },
  "r803": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123391704&loc=SL77918643-209977"
  },
  "r804": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918673-209980"
  },
  "r805": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980"
  },
  "r806": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980"
  },
  "r807": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980"
  },
  "r808": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(1)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980"
  },
  "r809": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(2)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980"
  },
  "r81": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313"
  },
  "r810": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(3)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980"
  },
  "r811": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(4)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980"
  },
  "r812": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980"
  },
  "r813": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918701-209980"
  },
  "r814": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "53",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123414884&loc=SL77918982-209971"
  },
  "r815": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/subtopic&trid=77888251"
  },
  "r816": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123420820&loc=SL77919311-209978"
  },
  "r817": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=124258985&loc=SL77919372-209981"
  },
  "r818": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "848",
   "URI": "http://asc.fasb.org/extlink&oid=122150657&loc=SL122150809-237846"
  },
  "r819": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "850",
   "URI": "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864"
  },
  "r82": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226003-175313"
  },
  "r820": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "850",
   "URI": "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864"
  },
  "r821": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "850",
   "URI": "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39599-107864"
  },
  "r822": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "850",
   "URI": "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864"
  },
  "r823": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "852",
   "URI": "http://asc.fasb.org/extlink&oid=124437977&loc=d3e55792-112764"
  },
  "r824": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "852",
   "URI": "http://asc.fasb.org/extlink&oid=124433192&loc=SL2890621-112765"
  },
  "r825": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "852",
   "URI": "http://asc.fasb.org/extlink&oid=124433192&loc=SL2890621-112765"
  },
  "r826": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "852",
   "URI": "http://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766"
  },
  "r827": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "855",
   "URI": "http://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662"
  },
  "r828": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=123598361&loc=d3e99978-111710"
  },
  "r829": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(2)(i)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r83": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226006-175313"
  },
  "r830": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(2)(ii)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r831": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r832": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r833": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r834": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r835": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r836": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r837": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r838": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r839": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r84": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=d3e526-108580"
  },
  "r840": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r841": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r842": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=SL51823488-111719"
  },
  "r843": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=66007379&loc=d3e113888-111728"
  },
  "r844": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=109249958&loc=SL34722452-111729"
  },
  "r845": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122625-111746"
  },
  "r846": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122625-111746"
  },
  "r847": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122625-111746"
  },
  "r848": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(4)(i)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122625-111746"
  },
  "r849": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r85": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669646-108580"
  },
  "r850": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r851": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r852": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(4)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r853": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(5)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r854": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(6)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r855": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(7)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r856": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(b)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r857": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(e)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r858": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(e)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r859": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(e)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r86": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669646-108580"
  },
  "r860": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "910",
   "URI": "http://asc.fasb.org/extlink&oid=123353855&loc=SL119991595-234733"
  },
  "r861": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "330",
   "Topic": "912",
   "URI": "http://asc.fasb.org/extlink&oid=6471895&loc=d3e55923-109411"
  },
  "r862": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 11.L)",
   "Topic": "924",
   "URI": "http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856"
  },
  "r863": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "310",
   "Topic": "940",
   "URI": "http://asc.fasb.org/subtopic&trid=2176284"
  },
  "r864": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "940",
   "URI": "http://asc.fasb.org/subtopic&trid=2176304"
  },
  "r865": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(1)(a))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r866": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(10)(1))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r867": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(11))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r868": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(13))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r869": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(16))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r87": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669646-108580"
  },
  "r870": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(23))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r871": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(6))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r872": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(7))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r873": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.10)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r874": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.17)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r875": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.4)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r876": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(13)(f))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r877": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(22))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r878": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(23))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r879": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(25))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r88": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(h)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669646-108580"
  },
  "r880": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(26))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r881": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(27))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r882": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.9)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r883": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "235",
   "Subparagraph": "(SX 210.9-05(b)(2))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399901&loc=d3e537907-122884"
  },
  "r884": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Subparagraph": "(b)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=d3e62557-112803"
  },
  "r885": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=d3e62557-112803"
  },
  "r886": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=d3e62586-112803"
  },
  "r887": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Subparagraph": "(a)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=SL120269850-112803"
  },
  "r888": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Subparagraph": "(b)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=SL120269850-112803"
  },
  "r889": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Subparagraph": "(c)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=SL120269850-112803"
  },
  "r89": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(i)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669646-108580"
  },
  "r890": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Subparagraph": "(d)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=SL120269850-112803"
  },
  "r891": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "942",
   "URI": "http://asc.fasb.org/subtopic&trid=2209399"
  },
  "r892": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "405",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6957935&loc=d3e64057-112817"
  },
  "r893": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "470",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599511&loc=d3e64711-112823"
  },
  "r894": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(16))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r895": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(12))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r896": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(16))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r897": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(2))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r898": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(23)(a)(3))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r899": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(23)(a)(4)(ii))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r9": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=d3e1361-107760"
  },
  "r90": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(i),(j),(k)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669646-108580"
  },
  "r900": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(23)(a)(4))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r901": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(25))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r902": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03.(a),19)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r903": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03.5(c))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r904": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(10))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r905": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(18))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r906": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(19))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r907": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(21))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r908": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(22))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r909": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(23))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r91": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(i-k)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669646-108580"
  },
  "r910": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(9))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r911": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4H",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=116884468&loc=SL65671331-158438"
  },
  "r912": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Subparagraph": "(d)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124506351&loc=SL117782755-158439"
  },
  "r913": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13H",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "40",
   "Subparagraph": "(a)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124504033&loc=SL117783719-158441"
  },
  "r914": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13H",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "40",
   "Subparagraph": "(b)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124504033&loc=SL117783719-158441"
  },
  "r915": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "29F",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "40",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124504033&loc=SL117819544-158441"
  },
  "r916": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(a)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r917": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(b)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r918": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(e)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r919": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(f)(1)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r92": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(j)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669646-108580"
  },
  "r920": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(f)(2)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r921": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(1)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r922": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(2)(i)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r923": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(2)(ii)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r924": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(2)(iii)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r925": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(2)(iv)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r926": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(h)(1)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r927": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(h)(2)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r928": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "505",
   "Topic": "944",
   "URI": "http://asc.fasb.org/subtopic&trid=4738323"
  },
  "r929": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "210",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=118262064&loc=SL116631418-115840"
  },
  "r93": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669646-108580"
  },
  "r930": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "210",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=118262064&loc=SL116631419-115840"
  },
  "r931": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "946",
   "URI": "http://asc.fasb.org/subtopic&trid=2324412"
  },
  "r932": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "310",
   "Subparagraph": "(SX 210.12-29(Footnote 4))",
   "Topic": "948",
   "URI": "http://asc.fasb.org/extlink&oid=120402547&loc=d3e617274-123014"
  },
  "r933": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "440",
   "Subparagraph": "(a)",
   "Topic": "954",
   "URI": "http://asc.fasb.org/extlink&oid=6491277&loc=d3e6429-115629"
  },
  "r934": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "360",
   "Subparagraph": "(d)",
   "Topic": "958",
   "URI": "http://asc.fasb.org/extlink&oid=120429125&loc=d3e99779-112916"
  },
  "r935": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "360",
   "Topic": "958",
   "URI": "http://asc.fasb.org/extlink&oid=120429125&loc=d3e99893-112916"
  },
  "r936": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "360",
   "Topic": "958",
   "URI": "http://asc.fasb.org/extlink&oid=120429125&loc=SL120174063-112916"
  },
  "r937": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column B))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r938": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column C))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r939": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column D))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r94": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=d3e637-108580"
  },
  "r940": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column E))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r941": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column F))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r942": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column G))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r943": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column H))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r944": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column I))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r945": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Footnote 2))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r946": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Footnote 4))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r947": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "310",
   "Subparagraph": "(c)",
   "Topic": "976",
   "URI": "http://asc.fasb.org/extlink&oid=6497875&loc=d3e22274-108663"
  },
  "r948": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "310",
   "Subparagraph": "(b)",
   "Topic": "978",
   "URI": "http://asc.fasb.org/extlink&oid=123360121&loc=d3e27327-108691"
  },
  "r949": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 10.D)",
   "Topic": "980",
   "URI": "http://asc.fasb.org/extlink&oid=122136240&loc=d3e659339-123030"
  },
  "r95": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=d3e640-108580"
  },
  "r950": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "980",
   "URI": "http://asc.fasb.org/extlink&oid=84167750&loc=d3e42232-110370"
  },
  "r951": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "340",
   "Topic": "980",
   "URI": "http://asc.fasb.org/extlink&oid=123417213&loc=d3e43603-110378"
  },
  "r952": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "340",
   "Topic": "980",
   "URI": "http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382"
  },
  "r953": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "340",
   "Topic": "980",
   "URI": "http://asc.fasb.org/extlink&oid=6499975&loc=d3e44264-110382"
  },
  "r954": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "340",
   "Topic": "980",
   "URI": "http://asc.fasb.org/extlink&oid=6499975&loc=d3e44278-110382"
  },
  "r955": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "360",
   "Topic": "980",
   "URI": "http://asc.fasb.org/extlink&oid=6500269&loc=d3e45485-110386"
  },
  "r956": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "405",
   "Topic": "980",
   "URI": "http://asc.fasb.org/extlink&oid=6500807&loc=d3e48068-110394"
  },
  "r957": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "715",
   "Topic": "980",
   "URI": "http://asc.fasb.org/extlink&oid=6501251&loc=d3e52485-110419"
  },
  "r958": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "740",
   "Topic": "980",
   "URI": "http://asc.fasb.org/extlink&oid=6501382&loc=d3e54053-110423"
  },
  "r959": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "740",
   "Topic": "980",
   "URI": "http://asc.fasb.org/extlink&oid=6501382&loc=d3e54136-110423"
  },
  "r96": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=d3e681-108580"
  },
  "r960": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "835",
   "Topic": "980",
   "URI": "http://asc.fasb.org/extlink&oid=6501569&loc=d3e55921-110430"
  },
  "r961": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "835",
   "Topic": "980",
   "URI": "http://asc.fasb.org/extlink&oid=6501662&loc=d3e56162-110433"
  },
  "r962": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "980",
   "URI": "http://asc.fasb.org/topic&trid=2156578"
  },
  "r963": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b"
  },
  "r964": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b-2"
  },
  "r965": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b-23"
  },
  "r966": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "d1-1"
  },
  "r967": {
   "Name": "Form 10-K",
   "Number": "249",
   "Publisher": "SEC",
   "Section": "310"
  },
  "r968": {
   "Name": "Form 20-F",
   "Number": "249",
   "Publisher": "SEC",
   "Section": "220",
   "Subsection": "f"
  },
  "r969": {
   "Name": "Form 40-F",
   "Number": "249",
   "Publisher": "SEC",
   "Section": "240",
   "Subsection": "f"
  },
  "r97": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669686-108580"
  },
  "r970": {
   "Name": "Forms 10-K, 10-Q, 20-F",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "13",
   "Subsection": "a-1"
  },
  "r971": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1402"
  },
  "r972": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(1)"
  },
  "r973": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(2)"
  },
  "r974": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(3)"
  },
  "r975": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(c)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(2)(i)"
  },
  "r976": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(c)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(2)(ii)"
  },
  "r977": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(c)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(2)(iii)"
  },
  "r978": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1403"
  },
  "r979": {
   "Name": "Regulation S-T",
   "Number": "232",
   "Publisher": "SEC",
   "Section": "405"
  },
  "r98": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=d3e689-108580"
  },
  "r980": {
   "Footnote": "2",
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "28"
  },
  "r981": {
   "Footnote": "4",
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "28"
  },
  "r982": {
   "Footnote": "4",
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "29"
  },
  "r983": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "04"
  },
  "r984": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "Column B",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "28"
  },
  "r985": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "Column C",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "28"
  },
  "r986": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "Column D",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "28"
  },
  "r987": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "Column E",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "28"
  },
  "r988": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "Column F",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "28"
  },
  "r989": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "Column G",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "28"
  },
  "r99": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL34724391-108580"
  },
  "r990": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "Column H",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "28"
  },
  "r991": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "Column I",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "28"
  },
  "r992": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "a",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "04"
  },
  "r993": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "09"
  },
  "r994": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "13",
   "Subparagraph": "(4)(i)",
   "Subsection": "01"
  },
  "r995": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "13",
   "Subparagraph": "(4)(i)",
   "Subsection": "02"
  },
  "r996": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "13",
   "Subparagraph": "(4)(ii)",
   "Subsection": "01"
  },
  "r997": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "13",
   "Subparagraph": "(4)(iii)",
   "Subsection": "01"
  },
  "r998": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "13",
   "Subparagraph": "(4)(iii)(A)",
   "Subsection": "01"
  },
  "r999": {
   "Name": "Regulation S-X (SX)",
   "Number": "210",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "13",
   "Subparagraph": "(4)(iii)(A)",
   "Subsection": "02"
  }
 },
 "version": "2.1"
}
