{
 "instance": {
  "jmsb-20220930x10q.htm": {
   "axisCustom": 0,
   "axisStandard": 22,
   "contextCount": 274,
   "dts": {
    "calculationLink": {
     "local": [
      "jmsb-20220930_cal.xml"
     ]
    },
    "definitionLink": {
     "local": [
      "jmsb-20220930_def.xml"
     ]
    },
    "inline": {
     "local": [
      "jmsb-20220930x10q.htm"
     ]
    },
    "labelLink": {
     "local": [
      "jmsb-20220930_lab.xml"
     ]
    },
    "presentationLink": {
     "local": [
      "jmsb-20220930_pre.xml"
     ]
    },
    "schema": {
     "local": [
      "jmsb-20220930.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/arcrole/esma-arcrole-2018-11-21.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": 598,
   "entityCount": 1,
   "hidden": {
    "http://fasb.org/us-gaap/2021-01-31": 7,
    "http://xbrl.sec.gov/dei/2021q4": 5,
    "total": 12
   },
   "keyCustom": 44,
   "keyStandard": 352,
   "memberCustom": 20,
   "memberStandard": 42,
   "nsprefix": "jmsb",
   "nsuri": "http://www.johnmarshallbank.com/20220930",
   "report": {
    "R1": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:DocumentType",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "document",
     "isDefault": "true",
     "longName": "00090 - Document - Document and Entity Information",
     "role": "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation",
     "shortName": "Document and Entity Information",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:DocumentType",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R10": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BusinessDescriptionAndAccountingPoliciesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10101 - Disclosure - Nature of Business and Summary of Significant Accounting Policies",
     "role": "http://www.johnmarshallbank.com/role/DisclosureNatureOfBusinessAndSummaryOfSignificantAccountingPolicies",
     "shortName": "Nature of Business and Summary of Significant Accounting Policies",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BusinessDescriptionAndAccountingPoliciesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R11": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10201 - Disclosure - Investment Securities",
     "role": "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecurities",
     "shortName": "Investment Securities",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R12": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LoansNotesTradeAndOtherReceivablesExcludingAllowanceForCreditLossesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10301 - Disclosure - Loans",
     "role": "http://www.johnmarshallbank.com/role/DisclosureLoans",
     "shortName": "Loans",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LoansNotesTradeAndOtherReceivablesExcludingAllowanceForCreditLossesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R13": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LoansNotesTradeAndOtherReceivablesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10401 - Disclosure - Allowance for Loan Losses",
     "role": "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLosses",
     "shortName": "Allowance for Loan Losses",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LoansNotesTradeAndOtherReceivablesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R14": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "jmsb:DepositsAndBorrowingsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10501 - Disclosure - Deposits and Borrowings",
     "role": "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowings",
     "shortName": "Deposits and Borrowings",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "jmsb:DepositsAndBorrowingsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R15": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeTaxDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10601 - Disclosure - Income Taxes",
     "role": "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxes",
     "shortName": "Income Taxes",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeTaxDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R16": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10701 - Disclosure - Commitments and Contingencies",
     "role": "http://www.johnmarshallbank.com/role/DisclosureCommitmentsAndContingencies",
     "shortName": "Commitments and Contingencies",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R17": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10801 - Disclosure - Fair Value Measurements",
     "role": "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurements",
     "shortName": "Fair Value Measurements",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R18": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10901 - Disclosure - Earnings per Common Share",
     "role": "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShare",
     "shortName": "Earnings per Common Share",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R19": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11001 - Disclosure - Stock Based Compensation Plan",
     "role": "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlan",
     "shortName": "Stock Based Compensation Plan",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R2": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:CashAndDueFromBanks",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00100 - Statement - Consolidated Balance Sheets",
     "role": "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets",
     "shortName": "Consolidated Balance Sheets",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:CashAndDueFromBanks",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R20": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11101 - Disclosure - Regulatory Capital",
     "role": "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapital",
     "shortName": "Regulatory Capital",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R21": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RevenueFromContractWithCustomerTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11201 - Disclosure - Revenue",
     "role": "http://www.johnmarshallbank.com/role/DisclosureRevenue",
     "shortName": "Revenue",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RevenueFromContractWithCustomerTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R22": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OtherOperatingIncomeAndExpenseTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11301 - Disclosure - Other Operating Expenses",
     "role": "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpenses",
     "shortName": "Other Operating Expenses",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OtherOperatingIncomeAndExpenseTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R23": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ComprehensiveIncomeNoteTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11401 - Disclosure - Accumulated Other Comprehensive Income (Loss)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLoss",
     "shortName": "Accumulated Other Comprehensive Income (Loss)",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ComprehensiveIncomeNoteTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R24": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:BusinessDescriptionAndAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NewAccountingPronouncementsPolicyPolicyTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "20102 - Disclosure - Nature of Business and Summary of Significant Accounting Policies (Policies)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureNatureOfBusinessAndSummaryOfSignificantAccountingPoliciesPolicies",
     "shortName": "Nature of Business and Summary of Significant Accounting Policies (Policies)",
     "subGroupType": "policies",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:BusinessDescriptionAndAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NewAccountingPronouncementsPolicyPolicyTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R25": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30203 - Disclosure - Investment Securities (Tables)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesTables",
     "shortName": "Investment Securities (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R26": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:LoansNotesTradeAndOtherReceivablesExcludingAllowanceForCreditLossesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30303 - Disclosure - Loans (Tables)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureLoansTables",
     "shortName": "Loans (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:LoansNotesTradeAndOtherReceivablesExcludingAllowanceForCreditLossesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R27": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:LoansNotesTradeAndOtherReceivablesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30403 - Disclosure - Allowance for Loan Losses (Tables)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesTables",
     "shortName": "Allowance for Loan Losses (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:LoansNotesTradeAndOtherReceivablesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R28": {
     "firstAnchor": {
      "ancestors": [
       "jmsb:DepositsAndBorrowingsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DepositLiabilitiesTypeTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30503 - Disclosure - Deposits and Borrowings (Tables)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTables",
     "shortName": "Deposits and Borrowings (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "jmsb:DepositsAndBorrowingsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DepositLiabilitiesTypeTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R29": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:IncomeTaxDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30603 - Disclosure - Income Taxes (Tables)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesTables",
     "shortName": "Income Taxes (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:IncomeTaxDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R3": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:HeldToMaturitySecuritiesFairValue",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00105 - Statement - Consolidated Balance Sheets (Parenthetical)",
     "role": "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical",
     "shortName": "Consolidated Balance Sheets (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "INF",
      "lang": null,
      "name": "us-gaap:PreferredStockParOrStatedValuePerShare",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Divide_USD_shares_rB4n4SitM0-ydKyw-L0SnQ",
      "xsiNil": "false"
     }
    },
    "R30": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfFairValueOffBalanceSheetRisksTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30703 - Disclosure - Commitments and Contingencies (Tables)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureCommitmentsAndContingenciesTables",
     "shortName": "Commitments and Contingencies (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfFairValueOffBalanceSheetRisksTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R31": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30803 - Disclosure - Fair Value Measurements (Tables)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsTables",
     "shortName": "Fair Value Measurements (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R32": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30903 - Disclosure - Earnings per Common Share (Tables)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareTables",
     "shortName": "Earnings per Common Share (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R33": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31003 - Disclosure - Stock Based Compensation Plan (Tables)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanTables",
     "shortName": "Stock Based Compensation Plan (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R34": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31103 - Disclosure - Regulatory Capital (Tables)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalTables",
     "shortName": "Regulatory Capital (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R35": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:RevenueFromContractWithCustomerTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisaggregationOfRevenueTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31203 - Disclosure - Revenue (Tables)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureRevenueTables",
     "shortName": "Revenue (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:RevenueFromContractWithCustomerTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisaggregationOfRevenueTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R36": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:OtherOperatingIncomeAndExpenseTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfOtherOperatingCostAndExpenseByComponentTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31303 - Disclosure - Other Operating Expenses (Tables)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesTables",
     "shortName": "Other Operating Expenses (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:OtherOperatingIncomeAndExpenseTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfOtherOperatingCostAndExpenseByComponentTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R37": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:ComprehensiveIncomeNoteTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31403 - Disclosure - Accumulated Other Comprehensive Income (Loss) (Tables)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLossTables",
     "shortName": "Accumulated Other Comprehensive Income (Loss) (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:ComprehensiveIncomeNoteTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R38": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:InvestmentTableTextBlock",
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40201 - Disclosure - Investment Securities - Amortized cost and fair value of securities held-to-maturity and available-for-sale (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
     "shortName": "Investment Securities - Amortized cost and fair value of securities held-to-maturity and available-for-sale (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:InvestmentTableTextBlock",
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R39": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40202 - Disclosure - Investment Securities - Fair value of securities held-to-maturity and available-for-sale (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
     "shortName": "Investment Securities - Fair value of securities held-to-maturity and available-for-sale (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R4": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_sKO55ya8vU2mdc5OrvgwEQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:InterestAndFeeIncomeLoansAndLeases",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00200 - Statement - Consolidated Statements of Income",
     "role": "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome",
     "shortName": "Consolidated Statements of Income",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_sKO55ya8vU2mdc5OrvgwEQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:InterestAndFeeIncomeLoansAndLeases",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R40": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:InvestmentsClassifiedByContractualMaturityDateTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40203 - Disclosure - Investment Securities - Contractual maturities of investment securities (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails",
     "shortName": "Investment Securities - Contractual maturities of investment securities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:InvestmentsClassifiedByContractualMaturityDateTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R41": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "jmsb:ScheduleOfRestrictedSecuritiesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FederalReserveBankStock",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40204 - Disclosure - Investment Securities - Carrying amount of restricted securities (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesCarryingAmountOfRestrictedSecuritiesDetails",
     "shortName": "Investment Securities - Carrying amount of restricted securities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "jmsb:ScheduleOfRestrictedSecuritiesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FederalReserveBankStock",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R42": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_12_31_2021_76lCpIX_A0a0G3uI2fJ87g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "jmsb:TransferFromAvailableForSaleToHeldToMaturityCarryingValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40205 - Disclosure - Investment Securities - Additional information (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails",
     "shortName": "Investment Securities - Additional information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_12_31_2021_76lCpIX_A0a0G3uI2fJ87g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "jmsb:TransferFromAvailableForSaleToHeldToMaturityCarryingValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R43": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
       "us-gaap:LoansNotesTradeAndOtherReceivablesExcludingAllowanceForCreditLossesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:LoansAndLeasesReceivableBeforeFeesGross",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40301 - Disclosure - Loans (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureLoansDetails",
     "shortName": "Loans (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
       "us-gaap:LoansNotesTradeAndOtherReceivablesExcludingAllowanceForCreditLossesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:LoansAndLeasesReceivableBeforeFeesGross",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R44": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ImpairedFinancingReceivablesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ImpairedFinancingReceivableRecordedInvestment",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40401 - Disclosure - Allowance for Loan Losses - Additional information (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails",
     "shortName": "Allowance for Loan Losses - Additional information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_12_31_2021_76lCpIX_A0a0G3uI2fJ87g",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:FinancingReceivableModificationsRecordedInvestment",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R45": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_12_31_2021_76lCpIX_A0a0G3uI2fJ87g",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:LoansAndLeasesReceivableAllowance",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40402 - Disclosure - Allowance for Loan Losses - Allowance for loan losses activity (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
     "shortName": "Allowance for Loan Losses - Allowance for loan losses activity (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock",
       "us-gaap:LoansNotesTradeAndOtherReceivablesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:AllowanceForLoanAndLeaseLossesWriteOffs",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R46": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock",
       "us-gaap:LoansNotesTradeAndOtherReceivablesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40403 - Disclosure - Allowance for Loan Losses - Balance of allowance for loan losses (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
     "shortName": "Allowance for Loan Losses - Balance of allowance for loan losses (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock",
       "us-gaap:LoansNotesTradeAndOtherReceivablesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R47": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ImpairedFinancingReceivablesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ImpairedFinancingReceivableUnpaidPrincipalBalance",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40404 - Disclosure - Allowance for Loan Losses - Impaired loans (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesImpairedLoansDetails",
     "shortName": "Allowance for Loan Losses - Impaired loans (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ImpairedFinancingReceivablesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ImpairedFinancingReceivableUnpaidPrincipalBalance",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R48": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:PastDueFinancingReceivablesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "jmsb:LoansAndLeasesReceivableCurrentCarryingAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40405 - Disclosure - Allowance for Loan Losses - Past due and non-accrual loans (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails",
     "shortName": "Allowance for Loan Losses - Past due and non-accrual loans (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:PastDueFinancingReceivablesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "jmsb:LoansAndLeasesReceivableCurrentCarryingAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R49": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock",
       "us-gaap:LoansNotesTradeAndOtherReceivablesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:LoansAndLeasesReceivableGrossCarryingAmount",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40406 - Disclosure - Allowance for Loan Losses - Schedule of credit quality information (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails",
     "shortName": "Allowance for Loan Losses - Schedule of credit quality information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:FinancingReceivableCreditQualityIndicatorsTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_us-gaap_InternalCreditAssessmentAxis_us-gaap_PassMember_m0wPrR0H8UeC9Lnydzvpyg",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:LoansAndLeasesReceivableGrossCarryingAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R5": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_sKO55ya8vU2mdc5OrvgwEQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00300 - Statement - Consolidated Statements of Comprehensive Income (Loss)",
     "role": "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss",
     "shortName": "Consolidated Statements of Comprehensive Income (Loss)",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_sKO55ya8vU2mdc5OrvgwEQ",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsNetOfTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R50": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:NoninterestBearingDepositLiabilities",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40501 - Disclosure - Deposits and Borrowings - Deposits (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsDepositsDetails",
     "shortName": "Deposits and Borrowings - Deposits (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R51": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfDebtInstrumentsTextBlock",
       "jmsb:DepositsAndBorrowingsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:LongTermDebt",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40502 - Disclosure - Deposits and Borrowings - Long-term Debt (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsLongTermDebtDetails",
     "shortName": "Deposits and Borrowings - Long-term Debt (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfDebtInstrumentsTextBlock",
       "jmsb:DepositsAndBorrowingsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:LongTermDebt",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R52": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:ScheduleOfDebtInstrumentsTextBlock",
       "jmsb:DepositsAndBorrowingsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DepositLiabilitiesReclassifiedAsLoansReceivable1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40503 - Disclosure - Deposits and Borrowings - Additional Information (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails",
     "shortName": "Deposits and Borrowings - Additional Information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:ScheduleOfDebtInstrumentsTextBlock",
       "jmsb:DepositsAndBorrowingsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DepositLiabilitiesReclassifiedAsLoansReceivable1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R53": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:TimeDepositMaturitiesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "jmsb:TimeDepositsAndFhlbAdvancesRemainderOfFiscalYear",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40504 - Disclosure - Deposits and Borrowings - Time deposits and FHLB advances by contractual maturity (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails",
     "shortName": "Deposits and Borrowings - Time deposits and FHLB advances by contractual maturity (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:TimeDepositMaturitiesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "jmsb:TimeDepositsAndFhlbAdvancesRemainderOfFiscalYear",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R54": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock",
       "us-gaap:IncomeTaxDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:CurrentIncomeTaxExpenseBenefit",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40601 - Disclosure - Income Taxes - Provision for income taxes (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesProvisionForIncomeTaxesDetails",
     "shortName": "Income Taxes - Provision for income taxes (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock",
       "us-gaap:IncomeTaxDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:CurrentIncomeTaxExpenseBenefit",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R55": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock",
       "us-gaap:IncomeTaxDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40602 - Disclosure - Income Taxes - Income tax rate reconciliation (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesIncomeTaxRateReconciliationDetails",
     "shortName": "Income Taxes - Income tax rate reconciliation (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock",
       "us-gaap:IncomeTaxDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R56": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfFairValueOffBalanceSheetRisksTextBlock",
       "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_us-gaap_FinancialInstrumentAxis_us-gaap_CommitmentsToExtendCreditMember_Q9HXQzJqn0a7iAAOQrfS_A",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40701 - Disclosure - Commitments and Contingencies (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureCommitmentsAndContingenciesDetails",
     "shortName": "Commitments and Contingencies (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfFairValueOffBalanceSheetRisksTextBlock",
       "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_us-gaap_FinancialInstrumentAxis_us-gaap_CommitmentsToExtendCreditMember_Q9HXQzJqn0a7iAAOQrfS_A",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R57": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:AvailableForSaleSecuritiesDebtSecurities",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40801 - Disclosure - Fair Value Measurements - Fair value of assets measured at fair value on a recurring basis (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails",
     "shortName": "Fair Value Measurements - Fair value of assets measured at fair value on a recurring basis (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_us-gaap_FairValueByMeasurementFrequencyAxis_us-gaap_FairValueMeasurementsRecurringMember_kyksj4XiWEqBGGt2vGAUCA",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:EquitySecuritiesFvNiCurrentAndNoncurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R58": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:AvailableForSaleSecuritiesDebtSecurities",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40802 - Disclosure - Fair Value Measurements - Carrying value and estimated fair value of financial instruments (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails",
     "shortName": "Fair Value Measurements - Carrying value and estimated fair value of financial instruments (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:FairValueByBalanceSheetGroupingTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_us-gaap_FairValueByMeasurementBasisAxis_us-gaap_CarryingReportedAmountFairValueDisclosureMember_6FMVKzB6YU2u4S0zz60a3g",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:CashAndCashEquivalentsFairValueDisclosure",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R59": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "jmsb:ImpairedLoans",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40803 - Disclosure - Fair Value Measurements - Additional information (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsAdditionalInformationDetails",
     "shortName": "Fair Value Measurements - Additional information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "jmsb:ImpairedLoans",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R6": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_sKO55ya8vU2mdc5OrvgwEQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesBeforeReclassificationAdjustmentsTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00305 - Statement - Consolidated Statements of Comprehensive Income (Loss) (Parenthetical)",
     "role": "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLossParenthetical",
     "shortName": "Consolidated Statements of Comprehensive Income (Loss) (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_sKO55ya8vU2mdc5OrvgwEQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesBeforeReclassificationAdjustmentsTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R60": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_sKO55ya8vU2mdc5OrvgwEQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40901 - Disclosure - Earnings per Common Share - Computation of earnings per share (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails",
     "shortName": "Earnings per Common Share - Computation of earnings per share (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_sKO55ya8vU2mdc5OrvgwEQ",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R61": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_us-gaap_EmployeeStockOptionMember_RCrZOcWms02wPXIoaxrJ_Q",
      "decimals": "0",
      "first": true,
      "lang": null,
      "name": "us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_ituJiVpqW0q3p7DqpV7Qsw",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40902 - Disclosure - Earnings per Common Share - Additional information (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareAdditionalInformationDetails",
     "shortName": "Earnings per Common Share - Additional information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_us-gaap_EmployeeStockOptionMember_RCrZOcWms02wPXIoaxrJ_Q",
      "decimals": "0",
      "first": true,
      "lang": null,
      "name": "us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_ituJiVpqW0q3p7DqpV7Qsw",
      "xsiNil": "false"
     }
    },
    "R62": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_us-gaap_AwardTypeAxis_us-gaap_EmployeeStockOptionMember_NR5uxgDvQ0exArgCNAqwFg",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41001 - Disclosure - Stock Based Compensation Plan (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails",
     "shortName": "Stock Based Compensation Plan (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_us-gaap_AwardTypeAxis_us-gaap_EmployeeStockOptionMember_NR5uxgDvQ0exArgCNAqwFg",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R63": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_12_31_2021_us-gaap_AwardTypeAxis_us-gaap_EmployeeStockOptionMember_nUqaytjARkGeoNKIKJGDdg",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber",
      "reportCount": 1,
      "unitRef": "Unit_Standard_shares_ituJiVpqW0q3p7DqpV7Qsw",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41002 - Disclosure - Stock Based Compensation Plan - Summary of Stock Options Activity (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails",
     "shortName": "Stock Based Compensation Plan - Summary of Stock Options Activity (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross",
       "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross",
       "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross",
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_us-gaap_AwardTypeAxis_us-gaap_EmployeeStockOptionMember_NR5uxgDvQ0exArgCNAqwFg",
      "decimals": "INF",
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_ituJiVpqW0q3p7DqpV7Qsw",
      "xsiNil": "false"
     }
    },
    "R64": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_us-gaap_AwardTypeAxis_us-gaap_EmployeeStockOptionMember_GvzZcmolNUmfd6dXRAgc9w",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber",
      "reportCount": 1,
      "unitRef": "Unit_Standard_shares_ituJiVpqW0q3p7DqpV7Qsw",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41003 - Disclosure - Stock Based Compensation Plan - Summary of Stock Options Outstanding and Exercisable (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails",
     "shortName": "Stock Based Compensation Plan - Summary of Stock Options Outstanding and Exercisable (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_us-gaap_AwardTypeAxis_us-gaap_EmployeeStockOptionMember_4HAPh-AvO0mPbcC7uaJPwA",
      "decimals": null,
      "lang": "en-US",
      "name": "us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R65": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:NonvestedRestrictedStockSharesActivityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_12_31_2021_us-gaap_AwardTypeAxis_us-gaap_RestrictedStockMember_43BOn2Vaik6g8zipTJUdRw",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_ituJiVpqW0q3p7DqpV7Qsw",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41004 - Disclosure - Stock Based Compensation Plan - Summary of Restricted Stock Awards (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfRestrictedStockAwardsDetails",
     "shortName": "Stock Based Compensation Plan - Summary of Restricted Stock Awards (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:NonvestedRestrictedStockSharesActivityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_12_31_2021_us-gaap_AwardTypeAxis_us-gaap_RestrictedStockMember_43BOn2Vaik6g8zipTJUdRw",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_ituJiVpqW0q3p7DqpV7Qsw",
      "xsiNil": "false"
     }
    },
    "R66": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "3",
      "first": true,
      "lang": null,
      "name": "us-gaap:BankingRegulationCapitalConservationBufferCommonEquityTierOneRiskBasedCapitalActual",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_cq3FpBafdkSFbdkT_oSIiQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41101 - Disclosure - Regulatory Capital (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalDetails",
     "shortName": "Regulatory Capital (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "3",
      "first": true,
      "lang": null,
      "name": "us-gaap:BankingRegulationCapitalConservationBufferCommonEquityTierOneRiskBasedCapitalActual",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_cq3FpBafdkSFbdkT_oSIiQ",
      "xsiNil": "false"
     }
    },
    "R67": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:Capital",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41102 - Disclosure - Regulatory Capital - Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails",
     "shortName": "Regulatory Capital - Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_9_30_2022_LbWvCnIpkkyv8bHl86JUbw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:Capital",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R68": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_sKO55ya8vU2mdc5OrvgwEQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:BankOwnedLifeInsuranceIncome",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41201 - Disclosure - Revenue - Components of Non-interest Income (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails",
     "shortName": "Revenue - Components of Non-interest Income (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:DisaggregationOfRevenueTableTextBlock",
       "us-gaap:RevenueFromContractWithCustomerTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_sKO55ya8vU2mdc5OrvgwEQ",
      "decimals": "-3",
      "lang": null,
      "name": "jmsb:OtherNoninterestOperatingIncomeExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R69": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:DisaggregationOfRevenueTableTextBlock",
       "us-gaap:RevenueFromContractWithCustomerTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_sKO55ya8vU2mdc5OrvgwEQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "jmsb:NoninterestIncomeOtherIncome",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41202 - Disclosure - Revenue - Additional information (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureRevenueAdditionalInformationDetails",
     "shortName": "Revenue - Additional information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:DisaggregationOfRevenueTableTextBlock",
       "us-gaap:RevenueFromContractWithCustomerTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_sKO55ya8vU2mdc5OrvgwEQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "jmsb:NoninterestIncomeOtherIncome",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R7": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_12_31_2020_us-gaap_StatementEquityComponentsAxis_us-gaap_CommonStockMember_owKldNXPMUaBLk8NCw7Ucg",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:StockholdersEquity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00400 - Statement - Consolidated Statements of Shareholders' Equity",
     "role": "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity",
     "shortName": "Consolidated Statements of Shareholders' Equity",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_12_31_2020_us-gaap_StatementEquityComponentsAxis_us-gaap_CommonStockMember_owKldNXPMUaBLk8NCw7Ucg",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:StockholdersEquity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R70": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfOtherOperatingCostAndExpenseByComponentTextBlock",
       "us-gaap:OtherOperatingIncomeAndExpenseTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_sKO55ya8vU2mdc5OrvgwEQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:AdvertisingExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41301 - Disclosure - Other Operating Expenses (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails",
     "shortName": "Other Operating Expenses (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfOtherOperatingCostAndExpenseByComponentTextBlock",
       "us-gaap:OtherOperatingIncomeAndExpenseTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_7_1_2022_To_9_30_2022_sKO55ya8vU2mdc5OrvgwEQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:AdvertisingExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R71": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "As_Of_6_30_2022_H8_QyAa9sUq5aungik3GMw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:StockholdersEquity",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41401 - Disclosure - Accumulated Other Comprehensive Income (Loss) (Details)",
     "role": "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLossDetails",
     "shortName": "Accumulated Other Comprehensive Income (Loss) (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:ComprehensiveIncomeNoteTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2021_To_9_30_2021_5Ut-w_hZkE2h-DRJEMkTCA",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:DebtSecuritiesAvailableForSaleRealizedGainLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    },
    "R8": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:CommonStockDividendsPerShareCashPaid",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Divide_USD_shares_rB4n4SitM0-ydKyw-L0SnQ",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00405 - Statement - Consolidated Statements of Shareholders' Equity (Parenthetical)",
     "role": "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquityParenthetical",
     "shortName": "Consolidated Statements of Shareholders' Equity (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:CommonStockDividendsPerShareCashPaid",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Divide_USD_shares_rB4n4SitM0-ydKyw-L0SnQ",
      "xsiNil": "false"
     }
    },
    "R9": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ProfitLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00500 - Statement - Consolidated Statements of Cash Flows",
     "role": "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows",
     "shortName": "Consolidated Statements of Cash Flows",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jmsb-20220930x10q.htm",
      "contextRef": "Duration_1_1_2022_To_9_30_2022_BgRvQTtZeUCG-DIm_qZt9Q",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ProfitLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_8O_06XBV60axY4ui2xYp1A",
      "xsiNil": "false"
     }
    }
   },
   "segmentCount": 64,
   "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"
       }
      }
     },
     "localname": "AmendmentFlag",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_CityAreaCode": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Area code of city",
        "label": "City Area Code"
       }
      }
     },
     "localname": "CityAreaCode",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_CoverAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cover page.",
        "label": "Document and Entity Information [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"
       }
      }
     },
     "localname": "CurrentFiscalYearEndDate",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "gMonthDayItemType"
    },
    "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"
       }
      }
     },
     "localname": "DocumentFiscalPeriodFocus",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "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"
       }
      }
     },
     "localname": "DocumentFiscalYearFocus",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "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"
       }
      }
     },
     "localname": "DocumentPeriodEndDate",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "dateItemType"
    },
    "dei_DocumentQuarterlyReport": {
     "auth_ref": [
      "r610"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true only for a form used as an quarterly report.",
        "label": "Document Quarterly Report"
       }
      }
     },
     "localname": "DocumentQuarterlyReport",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_DocumentTransitionReport": {
     "auth_ref": [
      "r611"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true only for a form used as a transition report.",
        "label": "Document Transition Report"
       }
      }
     },
     "localname": "DocumentTransitionReport",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "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"
       }
      }
     },
     "localname": "DocumentType",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "submissionTypeItemType"
    },
    "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"
       }
      }
     },
     "localname": "EntityAddressAddressLine1",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "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"
       }
      }
     },
     "localname": "EntityAddressAddressLine2",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressCityOrTown": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of the City or Town",
        "label": "Entity Address, City or Town"
       }
      }
     },
     "localname": "EntityAddressCityOrTown",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressPostalZipCode": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Code for the postal or zip code",
        "label": "Entity Address, Postal Zip Code"
       }
      }
     },
     "localname": "EntityAddressPostalZipCode",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressStateOrProvince": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of the state or province.",
        "label": "Entity Address State Or Province"
       }
      }
     },
     "localname": "EntityAddressStateOrProvince",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "stateOrProvinceItemType"
    },
    "dei_EntityCentralIndexKey": {
     "auth_ref": [
      "r608"
     ],
     "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"
       }
      }
     },
     "localname": "EntityCentralIndexKey",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "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"
       }
      }
     },
     "localname": "EntityCommonStockSharesOutstanding",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "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"
       }
      }
     },
     "localname": "EntityCurrentReportingStatus",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityEmergingGrowthCompany": {
     "auth_ref": [
      "r608"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate if registrant meets the emerging growth company criteria.",
        "label": "Entity Emerging Growth Company"
       }
      }
     },
     "localname": "EntityEmergingGrowthCompany",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntityExTransitionPeriod": {
     "auth_ref": [
      "r643"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate if an emerging growth company has elected not to use the extended transition period for complying with any new or revised financial accounting standards.",
        "label": "Entity Ex Transition Period"
       }
      }
     },
     "localname": "EntityExTransitionPeriod",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "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"
       }
      }
     },
     "localname": "EntityFileNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "fileNumberItemType"
    },
    "dei_EntityFilerCategory": {
     "auth_ref": [
      "r608"
     ],
     "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"
       }
      }
     },
     "localname": "EntityFilerCategory",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "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"
       }
      }
     },
     "localname": "EntityIncorporationStateCountryCode",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "edgarStateCountryItemType"
    },
    "dei_EntityInteractiveDataCurrent": {
     "auth_ref": [
      "r642"
     ],
     "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"
       }
      }
     },
     "localname": "EntityInteractiveDataCurrent",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityRegistrantName": {
     "auth_ref": [
      "r608"
     ],
     "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"
       }
      }
     },
     "localname": "EntityRegistrantName",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityShellCompany": {
     "auth_ref": [
      "r608"
     ],
     "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"
       }
      }
     },
     "localname": "EntityShellCompany",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntitySmallBusiness": {
     "auth_ref": [
      "r608"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates that the company is a Smaller Reporting Company (SRC).",
        "label": "Entity Small Business"
       }
      }
     },
     "localname": "EntitySmallBusiness",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntityTaxIdentificationNumber": {
     "auth_ref": [
      "r608"
     ],
     "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"
       }
      }
     },
     "localname": "EntityTaxIdentificationNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "employerIdItemType"
    },
    "dei_LocalPhoneNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Local phone number for entity.",
        "label": "Local Phone Number"
       }
      }
     },
     "localname": "LocalPhoneNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_Security12bTitle": {
     "auth_ref": [
      "r607"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Title of a 12(b) registered security.",
        "label": "Title of 12(b) Security"
       }
      }
     },
     "localname": "Security12bTitle",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "securityTitleItemType"
    },
    "dei_SecurityExchangeName": {
     "auth_ref": [
      "r609"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of the Exchange on which a security is registered.",
        "label": "Security Exchange Name"
       }
      }
     },
     "localname": "SecurityExchangeName",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "edgarExchangeCodeItemType"
    },
    "dei_TradingSymbol": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Trading symbol of an instrument as listed on an exchange.",
        "label": "Trading Symbol"
       }
      }
     },
     "localname": "TradingSymbol",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "tradingSymbolItemType"
    },
    "jmsb_AccountServiceFeesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to account service fees.",
        "label": "Account Service Fees [Member]",
        "terseLabel": "Account service fees"
       }
      }
     },
     "localname": "AccountServiceFeesMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_AccruedInterestPayableFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of the accrued interest payable.",
        "label": "Accrued Interest Payable, Fair Value Disclosure",
        "verboseLabel": "Accrued interest payable"
       }
      }
     },
     "localname": "AccruedInterestPayableFairValueDisclosure",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_AccruedInterestReceivableFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of the accrued interest receivable.",
        "label": "Accrued Interest Receivable, Fair Value Disclosure",
        "verboseLabel": "Accrued interest receivable"
       }
      }
     },
     "localname": "AccruedInterestReceivableFairValueDisclosure",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_AociAccumulatedGainLossDebtSecuritiesAvailableForSaleParentTransferredToHeldToMaturityMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to Unrealized Gains on Securities Transferred from Available-for-sale to Held-to-maturity.",
        "label": "AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent Transferred To Held to Maturity [Member]",
        "terseLabel": "Unrealized Gains on Securities Transferred from Available-for-sale to Held-to-maturity"
       }
      }
     },
     "localname": "AociAccumulatedGainLossDebtSecuritiesAvailableForSaleParentTransferredToHeldToMaturityMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLossDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_BankingRegulationCapitalConservationBufferAboveMinimumRequirement": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "It represents the capital conservation buffer ratio above minimum requirement.",
        "label": "Banking Regulation Capital Conservation Buffer Above Minimum Requirement",
        "terseLabel": "Capital conservation buffer ratio above minimum requirement"
       }
      }
     },
     "localname": "BankingRegulationCapitalConservationBufferAboveMinimumRequirement",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "jmsb_CertificateOfDeposits": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of certificate of deposits.",
        "label": "Certificate of Deposits",
        "terseLabel": "Certificate of deposits"
       }
      }
     },
     "localname": "CertificateOfDeposits",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_CommonStockNonvotingMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to common stock nonvoting.",
        "label": "Common Stock Nonvoting [Member]",
        "terseLabel": "Common stock, non voting"
       }
      }
     },
     "localname": "CommonStockNonvotingMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_CommonStockVotingMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to common stock voting.",
        "label": "Common Stock Voting [Member]",
        "terseLabel": "Common stock, voting"
       }
      }
     },
     "localname": "CommonStockVotingMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_CommunityBankersBankStock": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesCarryingAmountOfRestrictedSecuritiesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_RestrictedInvestments",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Community Bankers' Bank Stock stock represents an equity interest in a Community Bankers' Bank.  It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).",
        "label": "Community Bankers Bank Stock",
        "terseLabel": "Community Bankers' Bank Stock"
       }
      }
     },
     "localname": "CommunityBankersBankStock",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesCarryingAmountOfRestrictedSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_DataProcessingExpense": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_OtherNoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of expenses incurred during the period for data processing.",
        "label": "Data Processing Expense",
        "terseLabel": "Data processing"
       }
      }
     },
     "localname": "DataProcessingExpense",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionFairValueAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "No definition available.",
        "label": "Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Fair Value [Abstract]",
        "terseLabel": "Available-for-sale, Fair Value"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionFairValueAbstract",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "jmsb_DebtSecuritiesUnrealizedLossPositionNumberOfPositions": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income, in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.",
        "label": "Debt Securities, Unrealized Loss Position, Number of Positions",
        "terseLabel": "Number of positions"
       }
      }
     },
     "localname": "DebtSecuritiesUnrealizedLossPositionNumberOfPositions",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "jmsb_DepositsAndBorrowingsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "No definition available.",
        "label": "Deposits and Borrowings"
       }
      }
     },
     "localname": "DepositsAndBorrowingsAbstract",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "xbrltype": "stringItemType"
    },
    "jmsb_DepositsAndBorrowingsTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for deposits and borrowings.",
        "label": "Deposits and Borrowings [Text Block]",
        "terseLabel": "Deposits and Borrowings"
       }
      }
     },
     "localname": "DepositsAndBorrowingsTextBlock",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowings"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jmsb_ExercisePriceRangeFourMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to exercise price range four.",
        "label": "Exercise Price Range Four [Member]",
        "terseLabel": "$16.01 - $18.16"
       }
      }
     },
     "localname": "ExercisePriceRangeFourMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_ExercisePriceRangeOneMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to exercise price range one.",
        "label": "Exercise Price Range One [Member]",
        "terseLabel": "$0.00 - $11.00"
       }
      }
     },
     "localname": "ExercisePriceRangeOneMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_ExercisePriceRangeThreeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to exercise price range three.",
        "label": "Exercise Price Range Three [Member]",
        "terseLabel": "12.01 - $16.00"
       }
      }
     },
     "localname": "ExercisePriceRangeThreeMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_ExercisePricesRangeTwoMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to exercise price range two.",
        "label": "$11.01 - $12.00"
       }
      }
     },
     "localname": "ExercisePricesRangeTwoMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_FairValueAdjustmentOnEquitySecurities": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 7.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of fair value adjustment on equity securities.",
        "label": "Fair Value Adjustment on Equity Securities",
        "terseLabel": "Fair value adjustment on equity securities"
       }
      }
     },
     "localname": "FairValueAdjustmentOnEquitySecurities",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosureAmountOfAvailableUnusedFunds": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Federal home loan bank advances general debt obligations disclosures amount of available unused funds.",
        "label": "Federal Home Loan Bank Advances General Debt Obligations Disclosure Amount of Available Unused Funds",
        "terseLabel": "Federal home loan, advances, general debt obligations, unused funds"
       }
      }
     },
     "localname": "FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosureAmountOfAvailableUnusedFunds",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_FinancingReceivableTroubledDebtRestructuringAdditionalCommitmentToDisburseFunds": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Additional commitment to disburse funds on financing receivable contracts modified as troubled debt restructuring.",
        "label": "Financing Receivable, Troubled Debt Restructuring, Additional Commitment To Disburse Funds"
       }
      }
     },
     "localname": "FinancingReceivableTroubledDebtRestructuringAdditionalCommitmentToDisburseFunds",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_FinancingReceivableTroubledDebtRestructuringNumberOfContractsThatRequireSpecialReserve": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of financing receivable contracts modified as troubled debt restructuring, that require special reserve.",
        "label": "Financing Receivable, Troubled Debt Restructuring, Number Of Contracts That Require Special Reserve"
       }
      }
     },
     "localname": "FinancingReceivableTroubledDebtRestructuringNumberOfContractsThatRequireSpecialReserve",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "jmsb_ImpairedLoans": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of no impaired loans with a recorded reserve.",
        "label": "Impaired Loans",
        "terseLabel": "Impaired loans with recorded reserve"
       }
      }
     },
     "localname": "ImpairedLoans",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_IncreaseInCashSurrenderValueOfLifeInsurance": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 12.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase in cash surrender value of life insurance.",
        "label": "Increase in Cash Surrender Value of Life Insurance",
        "negatedLabel": "Net increase in cash surrender value of life insurance"
       }
      }
     },
     "localname": "IncreaseInCashSurrenderValueOfLifeInsurance",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_InsuranceCommissionNonInterestIncome": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      },
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 6.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of insurance commissions.",
        "label": "Insurance Commission Non-Interest Income",
        "terseLabel": "Insurance commissions"
       }
      }
     },
     "localname": "InsuranceCommissionNonInterestIncome",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_InsuranceCommissionsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to insurance commissions.",
        "label": "Insurance Commissions"
       }
      }
     },
     "localname": "InsuranceCommissionsMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_InterchangeIncomeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to interchange income.",
        "label": "Interchange income [Member]",
        "terseLabel": "Interchange income"
       }
      }
     },
     "localname": "InterchangeIncomeMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_InvestmentWeightedAverageRemainingLife": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of the remaining average remaining life for investments.",
        "label": "Investment Weighted Average Remaining Life",
        "terseLabel": "Estimated weighted average remaining life"
       }
      }
     },
     "localname": "InvestmentWeightedAverageRemainingLife",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "jmsb_LoansAndLeasesReceivableCurrentCarryingAmount": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "It represents the loans and leases receivable, current carrying amount.",
        "label": "Loans and Leases Receivable Current Carrying Amount",
        "terseLabel": "Current"
       }
      }
     },
     "localname": "LoansAndLeasesReceivableCurrentCarryingAmount",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_NetPurchaseRedemptionOfRestrictedSecurities": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of net (purchase) redemption of restricted securities.",
        "label": "Net (Purchase) Redemption of Restricted Securities",
        "negatedLabel": "Net redemption of restricted securities"
       }
      }
     },
     "localname": "NetPurchaseRedemptionOfRestrictedSecurities",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_NonInterestIncomeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to non interest income.",
        "label": "Non-interest income [Member]",
        "terseLabel": "Non-interest income"
       }
      }
     },
     "localname": "NonInterestIncomeMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_NoninterestIncomeOtherIncome": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of other income recognized within the scope of ASC 606.",
        "label": "Noninterest Income, Other Income",
        "terseLabel": "Other operating income (loss)"
       }
      }
     },
     "localname": "NoninterestIncomeOtherIncome",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_NumberOfDepositorsRepresentingFivePercentOrMoreOfTotalDeposits": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of depositors representing five percent or more of total deposits.",
        "label": "Number Of Depositors Representing Five Percent Or More Of Total Deposits",
        "terseLabel": "Number of depositors representing five percent or more of total deposits"
       }
      }
     },
     "localname": "NumberOfDepositorsRepresentingFivePercentOrMoreOfTotalDeposits",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "jmsb_OtherChargesAndFeesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to other charges and fees.",
        "label": "Other Charges and Fees"
       }
      }
     },
     "localname": "OtherChargesAndFeesMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_OtherNoninterestOperatingIncomeExpense": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The net amount of other non-interest operating income and expenses.",
        "label": "Other Noninterest Operating Income Expense",
        "terseLabel": "Other operating income (loss)"
       }
      }
     },
     "localname": "OtherNoninterestOperatingIncomeExpense",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_OtherServiceChargesAndFees": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 3.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of other service charges and fees.",
        "label": "Other Service Charges and Fees",
        "terseLabel": "Other service charges and fees"
       }
      }
     },
     "localname": "OtherServiceChargesAndFees",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_OverdrawnAccountFeesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to overdrawn account fees.",
        "label": "Overdrawn Account Fees [Member]",
        "terseLabel": "Overdrawn account fees"
       }
      }
     },
     "localname": "OverdrawnAccountFeesMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_PaycheckProtectionProgramLoansMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents information pertaining to paycheck protection program loans.",
        "label": "PPP Loan"
       }
      }
     },
     "localname": "PaycheckProtectionProgramLoansMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_PercentageOfDepositsExceedsFiveOrMore": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Percentage of deposits exceed five or more.",
        "label": "Percentage of Deposits Exceeds Five or More",
        "terseLabel": "Percentage of deposits exceed five or more"
       }
      }
     },
     "localname": "PercentageOfDepositsExceedsFiveOrMore",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "jmsb_PledgedAssetsSeparatelyReportedSecuritiesPledgedAsCollateralAmortizedCost": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amortized cost of securities pledged as collateral.",
        "label": "Pledged Assets Separately Reported, Securities Pledged as Collateral, Amortized Cost",
        "terseLabel": "Pledged securities, amortized cost"
       }
      }
     },
     "localname": "PledgedAssetsSeparatelyReportedSecuritiesPledgedAsCollateralAmortizedCost",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_PremisesAndEquipmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to gains (losses) on premises and equipment.",
        "label": "Premises And Equipment"
       }
      }
     },
     "localname": "PremisesAndEquipmentMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_RealEstatePortfolioSegmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents information pertaining to Real estate portfolio segment.",
        "label": "Real Estate Portfolio Segment [Member]",
        "terseLabel": "Real Estate Loans"
       }
      }
     },
     "localname": "RealEstatePortfolioSegmentMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesImpairedLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_ReciprocalCertificatesOfDeposits": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Carrying amount as of the balance sheet date of reciprocal certificate of deposits.",
        "label": "Reciprocal Certificates Of Deposits",
        "terseLabel": "Reciprocal certificates of deposits"
       }
      }
     },
     "localname": "ReciprocalCertificatesOfDeposits",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_ReciprocalDemandAndMoneyMarketDeposit": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Carrying amount as of the balance sheet date of reciprocal demand and money market deposits.",
        "label": "Reciprocal Demand And Money Market Deposit",
        "terseLabel": "Reciprocal demand and money market deposit"
       }
      }
     },
     "localname": "ReciprocalDemandAndMoneyMarketDeposit",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_ScheduleOfRestrictedSecuritiesTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of investment in restricted securities.",
        "label": "Schedule of Restricted Securities [Table Text Block]",
        "terseLabel": "Summary of restricted securities"
       }
      }
     },
     "localname": "ScheduleOfRestrictedSecuritiesTableTextBlock",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jmsb_ServiceChargesOnDepositAccountsAndOtherServiceChargesAndFeesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "No definition available.",
        "label": "Service Charges on Deposit Accounts and Other Service Charges and Fees [Abstract]",
        "terseLabel": "Service charges on deposit accounts and Other service charges and fees"
       }
      }
     },
     "localname": "ServiceChargesOnDepositAccountsAndOtherServiceChargesAndFeesAbstract",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "jmsb_StateFranchiseTax": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_OtherNoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of state franchise taxes incurred during the period.",
        "label": "State Franchise Tax",
        "terseLabel": "State franchise tax"
       }
      }
     },
     "localname": "StateFranchiseTax",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_SubordinatedNotes5.75NotesIssuedOnJuly62017Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Borrowings from the 5.75% subordinated notes issued on July 6, 2017.",
        "label": "2017 Notes"
       }
      }
     },
     "localname": "SubordinatedNotes5.75NotesIssuedOnJuly62017Member",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssetsWithBuffer": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ratio of minimum Tier 1 risk-based capital to risk-weighted assets required for capital adequacy with buffer.",
        "label": "Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets with Buffer",
        "terseLabel": "Minimum Capital Requirements, Ratio"
       }
      }
     },
     "localname": "TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssetsWithBuffer",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "jmsb_TierOneRiskBasedCapitalRequiredForCapitalAdequacyWithBuffer": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of minimum Tier 1 risk-based capital required for capital adequacy with Buffer.",
        "label": "Tier One Risk Based Capital Required For Capital Adequacy with Buffer",
        "terseLabel": "Minimum Capital Requirements, Amount"
       }
      }
     },
     "localname": "TierOneRiskBasedCapitalRequiredForCapitalAdequacyWithBuffer",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_TimeDepositsAndFhlbAdvances": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit liabilities and Fhlp advances.",
        "label": "Time Deposits and Fhlb Advances",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "TimeDepositsAndFhlbAdvances",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_TimeDepositsAndFhlbAdvancesAfterYearFour": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails": {
       "order": 6.0,
       "parentTag": "jmsb_TimeDepositsAndFhlbAdvances",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit and Fhlp advances maturing after fourth fiscal year following current fiscal year.",
        "label": "Time Deposits and Fhlb Advances, after Year Four",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "TimeDepositsAndFhlbAdvancesAfterYearFour",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_TimeDepositsAndFhlbAdvancesRemainderOfFiscalYear": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails": {
       "order": 1.0,
       "parentTag": "jmsb_TimeDepositsAndFhlbAdvances",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit and Fhlp advances maturing in remainder of current fiscal year.",
        "label": "Time Deposits and Fhlb Advances, Remainder of Fiscal Year",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "TimeDepositsAndFhlbAdvancesRemainderOfFiscalYear",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_TimeDepositsAndFhlbAdvancesYearFour": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails": {
       "order": 5.0,
       "parentTag": "jmsb_TimeDepositsAndFhlbAdvances",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit and Fhlp advances maturing in fourth fiscal year following current fiscal year.",
        "label": "Time Deposits and Fhlb Advances, Year Four",
        "terseLabel": "2026"
       }
      }
     },
     "localname": "TimeDepositsAndFhlbAdvancesYearFour",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_TimeDepositsAndFhlbAdvancesYearOne": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails": {
       "order": 2.0,
       "parentTag": "jmsb_TimeDepositsAndFhlbAdvances",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit and Fhlp advances maturing in next fiscal year following current fiscal year.",
        "label": "Time Deposits and Fhlb Advances, Year One",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "TimeDepositsAndFhlbAdvancesYearOne",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_TimeDepositsAndFhlbAdvancesYearThree": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails": {
       "order": 4.0,
       "parentTag": "jmsb_TimeDepositsAndFhlbAdvances",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit and Fhlp advances maturing in third fiscal year following current fiscal year",
        "label": "Time Deposits and Fhlb Advances, Year Three",
        "terseLabel": "2025"
       }
      }
     },
     "localname": "TimeDepositsAndFhlbAdvancesYearThree",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_TimeDepositsAndFhlbAdvancesYearTwo": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails": {
       "order": 3.0,
       "parentTag": "jmsb_TimeDepositsAndFhlbAdvances",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit and Fhlp advances maturing in second fiscal year following current fiscal year.",
        "label": "Time Deposits and Fhlb Advances, Year Two",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "TimeDepositsAndFhlbAdvancesYearTwo",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_TransferFromAvailableForSaleToHeldToMaturityCarryingValue": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The carrying value of transfer from available for sale to held-to-maturity securities.",
        "label": "Transfer From Available For Sale To Held-to-Maturity, Carrying Value",
        "terseLabel": "Transferred investment securities, carrying value"
       }
      }
     },
     "localname": "TransferFromAvailableForSaleToHeldToMaturityCarryingValue",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_TransferFromAvailableForSaleToHeldToMaturityUnrealizedGain": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The unrealized gain of transfer from available for sale to held-to-maturity securities.",
        "label": "Transfer From Available For Sale To Held-to-Maturity, Unrealized Gain",
        "terseLabel": "Transferred investment securities, unrealized gain"
       }
      }
     },
     "localname": "TransferFromAvailableForSaleToHeldToMaturityUnrealizedGain",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_TwoThousandAndFifteenPlanMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents information pertaining to 2015 Plan.",
        "label": "Two Thousand And Fifteen Plan [Member]",
        "terseLabel": "2015 Plan"
       }
      }
     },
     "localname": "TwoThousandAndFifteenPlanMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_TwoThousandAndSixPlanMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents information pertaining to 2006 Plan.",
        "label": "Two Thousand And Six Plan [Member]",
        "terseLabel": "2006 Plan"
       }
      }
     },
     "localname": "TwoThousandAndSixPlanMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_UnrealizedGainLossOnSecuritiesAvailableForSale": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of unrealized gain (loss) on securities available for sale.",
        "label": "Unrealized Gain Loss on Securities Available For Sale",
        "terseLabel": "Unrealized loss on securities available-for-sale"
       }
      }
     },
     "localname": "UnrealizedGainLossOnSecuritiesAvailableForSale",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jmsb_UnvestedStockAwardsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the information pertaining to unvested stock awards.",
        "label": "Unvested Stock Awards [Member]",
        "terseLabel": "Unvested shares"
       }
      }
     },
     "localname": "UnvestedStockAwardsMember",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "domainItemType"
    },
    "jmsb_WeightedAverageNumberBasicSharesOutstandingAdjustmentOnUnvestedRestrictedStockAwards": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "It represents the reductions of unvested restricted stock from the weighted average shares outstanding, basic.",
        "label": "Weighted Average Number Basic Shares Outstanding Adjustment On Unvested Restricted Stock Awards",
        "negatedLabel": "Less: Unvested restricted stock"
       }
      }
     },
     "localname": "WeightedAverageNumberBasicSharesOutstandingAdjustmentOnUnvestedRestrictedStockAwards",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "jmsb_WeightedAverageNumberBasicSharesOutstandingIncludingUnvestedRestrictedStockAwards": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "It represents the weighted average common shares outstanding, including unvested restricted stock, basic.",
        "label": "Weighted Average Number Basic Shares Outstanding Including Unvested Restricted Stock Awards",
        "terseLabel": "Common shares outstanding, including unvested restricted stock"
       }
      }
     },
     "localname": "WeightedAverageNumberBasicSharesOutstandingIncludingUnvestedRestrictedStockAwards",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "jmsb_WeightedAverageNumberDilutedSharesOutstandingAdjustmentOnUnvestedRestrictedStockAwards": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "It represents the reductions of unvested restricted stock from the weighted average shares outstanding, diluted.",
        "label": "Weighted Average Number Diluted Shares Outstanding Adjustment on Unvested Restricted Stock Awards",
        "negatedLabel": "Less: Unvested restricted stock"
       }
      }
     },
     "localname": "WeightedAverageNumberDilutedSharesOutstandingAdjustmentOnUnvestedRestrictedStockAwards",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "jmsb_WeightedAverageNumberDilutedSharesOutstandingIncludingUnvestedRestrictedStockAwards": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "It represents the weighted average common shares outstanding, including unvested restricted stock, diluted.",
        "label": "Weighted Average Number Diluted Shares Outstanding Including Unvested Restricted Stock Awards",
        "terseLabel": "Common shares outstanding, including unvested restricted stock"
       }
      }
     },
     "localname": "WeightedAverageNumberDilutedSharesOutstandingIncludingUnvestedRestrictedStockAwards",
     "nsuri": "http://www.johnmarshallbank.com/20220930",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "srt_MaximumMember": {
     "auth_ref": [
      "r288",
      "r310",
      "r349",
      "r350",
      "r474",
      "r475",
      "r476",
      "r477",
      "r478",
      "r479",
      "r499",
      "r586",
      "r588",
      "r605",
      "r606"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Maximum",
        "terseLabel": "Maximum"
       }
      }
     },
     "localname": "MaximumMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_MinimumMember": {
     "auth_ref": [
      "r288",
      "r310",
      "r349",
      "r350",
      "r474",
      "r475",
      "r476",
      "r477",
      "r478",
      "r479",
      "r499",
      "r586",
      "r588",
      "r605",
      "r606"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Minimum",
        "terseLabel": "Minimum"
       }
      }
     },
     "localname": "MinimumMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ProductOrServiceAxis": {
     "auth_ref": [
      "r156",
      "r330",
      "r332",
      "r500",
      "r585",
      "r587"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Product and Service [Axis]"
       }
      }
     },
     "localname": "ProductOrServiceAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ProductsAndServicesDomain": {
     "auth_ref": [
      "r156",
      "r330",
      "r332",
      "r500",
      "r585",
      "r587"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Product and Service [Domain]"
       }
      }
     },
     "localname": "ProductsAndServicesDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RangeAxis": {
     "auth_ref": [
      "r288",
      "r310",
      "r340",
      "r349",
      "r350",
      "r474",
      "r475",
      "r476",
      "r477",
      "r478",
      "r479",
      "r499",
      "r586",
      "r588",
      "r605",
      "r606"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Statistical Measurement [Axis]"
       }
      }
     },
     "localname": "RangeAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureRevenueAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_RangeMember": {
     "auth_ref": [
      "r288",
      "r310",
      "r340",
      "r349",
      "r350",
      "r474",
      "r475",
      "r476",
      "r477",
      "r478",
      "r479",
      "r499",
      "r586",
      "r588",
      "r605",
      "r606"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Statistical Measurement [Domain]"
       }
      }
     },
     "localname": "RangeMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureRevenueAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RegulatoryCapitalRequirementsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Regulatory Capital"
       }
      }
     },
     "localname": "RegulatoryCapitalRequirementsAbstract",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccountingPoliciesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Nature of Business and Summary of Significant Accounting Policies"
       }
      }
     },
     "localname": "AccountingPoliciesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "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]"
       }
      }
     },
     "localname": "AccountsNotesAndLoansReceivableLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis": {
     "auth_ref": [
      "r27"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of receivable.",
        "label": "Receivable Type [Axis]"
       }
      }
     },
     "localname": "AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments": {
     "auth_ref": [
      "r82"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The sum of the periodic adjustments of the differences between securities' face values and purchase prices that are charged against earnings. This is called accretion if the security was purchased at a discount and amortization if it was purchased at premium. As a noncash item, this element is an adjustment to net income when calculating cash provided by or used in operations using the indirect method.",
        "label": "Accretion (Amortization) of Discounts and Premiums, Investments",
        "negatedLabel": "Net amortization of securities"
       }
      }
     },
     "localname": "AccretionAmortizationOfDiscountsAndPremiumsInvestments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember": {
     "auth_ref": [
      "r29",
      "r30",
      "r31",
      "r36",
      "r45",
      "r46",
      "r47"
     ],
     "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 Gain (Loss) on Available-for-sale Securities"
       }
      }
     },
     "localname": "AccumulatedNetUnrealizedInvestmentGainLossMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLossDetails"
     ],
     "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]"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeLossLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLossDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax": {
     "auth_ref": [
      "r13",
      "r33",
      "r35",
      "r36",
      "r573",
      "r593",
      "r594"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 5.0,
       "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 loss"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeLossNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTaxAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Accumulated Other Comprehensive Income (Loss)"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeLossNetOfTaxAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeLossTable": {
     "auth_ref": [
      "r45",
      "r46",
      "r447",
      "r448",
      "r449",
      "r450",
      "r451",
      "r453"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about components of accumulated other comprehensive income (loss).",
        "label": "Accumulated Other Comprehensive Income (Loss) [Table]"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeLossTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLossDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeMember": {
     "auth_ref": [
      "r32",
      "r36",
      "r45",
      "r46",
      "r47",
      "r96",
      "r97",
      "r98",
      "r420",
      "r589",
      "r590",
      "r644"
     ],
     "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": "Accumulated Other Comprehensive Income (Loss)"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLossDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AdditionalPaidInCapital": {
     "auth_ref": [
      "r11",
      "r385",
      "r467"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 3.0,
       "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": "Additional paid-in capital"
       }
      }
     },
     "localname": "AdditionalPaidInCapital",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AdditionalPaidInCapitalMember": {
     "auth_ref": [
      "r96",
      "r97",
      "r98",
      "r382",
      "r383",
      "r384",
      "r428"
     ],
     "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": "Additional Paid-in Capital"
       }
      }
     },
     "localname": "AdditionalPaidInCapitalMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue": {
     "auth_ref": [
      "r351",
      "r353",
      "r387",
      "r388"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase to additional paid-in capital (APIC) for recognition of cost for award under share-based payment arrangement.",
        "label": "APIC, Share-based Payment Arrangement, Increase for Cost Recognition",
        "terseLabel": "Share-based compensation"
       }
      }
     },
     "localname": "AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "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": "Adjustment to reconcile net income to net cash provided by operating activities:"
       }
      }
     },
     "localname": "AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AdvancesFromFederalHomeLoanBanks": {
     "auth_ref": [
      "r556"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.",
        "label": "Advances from Federal Home Loan Banks",
        "terseLabel": "Federal Home Loan Bank advances"
       }
      }
     },
     "localname": "AdvancesFromFederalHomeLoanBanks",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AdvertisingExpense": {
     "auth_ref": [
      "r391"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_OtherNoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line.",
        "label": "Advertising Expense",
        "terseLabel": "Advertising expense"
       }
      }
     },
     "localname": "AdvertisingExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AllocatedShareBasedCompensationExpense": {
     "auth_ref": [
      "r353",
      "r378",
      "r386"
     ],
     "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": "Share-based compensation expense"
       }
      }
     },
     "localname": "AllocatedShareBasedCompensationExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock": {
     "auth_ref": [
      "r166",
      "r238"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of allowance for credit loss on financing receivable.",
        "label": "Financing Receivable, Allowance for Credit Loss [Table Text Block]",
        "terseLabel": "Schedule of allowance for loan losses activity and balance"
       }
      }
     },
     "localname": "AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts": {
     "auth_ref": [
      "r163"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.",
        "label": "Allowance for Loan and Lease Loss, Recovery of Bad Debts",
        "terseLabel": "Recoveries"
       }
      }
     },
     "localname": "AllowanceForLoanAndLeaseLossRecoveryOfBadDebts",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs": {
     "auth_ref": [
      "r162"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.",
        "label": "Allowance for Loan and Lease Losses, Write-offs",
        "terseLabel": "Charge-offs"
       }
      }
     },
     "localname": "AllowanceForLoanAndLeaseLossesWriteOffs",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AmortizationOfFinancingCosts": {
     "auth_ref": [
      "r56",
      "r81",
      "r301",
      "r457"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 8.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of amortization expense attributable to debt issuance costs.",
        "label": "Amortization of Debt Issuance Costs",
        "terseLabel": "Amortization of debt issuance costs"
       }
      }
     },
     "localname": "AmortizationOfFinancingCosts",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount": {
     "auth_ref": [
      "r130"
     ],
     "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 securities excluded from computation of earnings per share, amount"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareAdditionalInformationDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis": {
     "auth_ref": [
      "r130"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of antidilutive security.",
        "label": "Antidilutive Securities [Axis]"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareAdditionalInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems": {
     "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": "Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]",
        "terseLabel": "Antidilutive securities excluded from computation of earnings per share"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareAdditionalInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AntidilutiveSecuritiesNameDomain": {
     "auth_ref": [
      "r130"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Incremental common shares attributable to securities that were not included in diluted earnings per share (EPS) because to do so would increase EPS amounts or decrease loss per share amounts for the period presented.",
        "label": "Antidilutive Securities, Name [Domain]"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareAdditionalInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_Assets": {
     "auth_ref": [
      "r89",
      "r145",
      "r148",
      "r154",
      "r231",
      "r274",
      "r275",
      "r276",
      "r277",
      "r278",
      "r279",
      "r280",
      "r281",
      "r282",
      "r283",
      "r284",
      "r415",
      "r421",
      "r445",
      "r465",
      "r467",
      "r506",
      "r571"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "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",
        "totalLabel": "Total assets"
       }
      }
     },
     "localname": "Assets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Assets [Abstract]",
        "terseLabel": "Assets"
       }
      }
     },
     "localname": "AssetsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AssetsFairValueDisclosure": {
     "auth_ref": [
      "r431"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.",
        "label": "Assets, Fair Value Disclosure",
        "terseLabel": "Total assets at fair value"
       }
      }
     },
     "localname": "AssetsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetsFairValueDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Assets, Fair Value Disclosure [Abstract]",
        "terseLabel": "Assets:"
       }
      }
     },
     "localname": "AssetsFairValueDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax": {
     "auth_ref": [
      "r193"
     ],
     "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": "Gross Unrealized Gains"
       }
      }
     },
     "localname": "AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax": {
     "auth_ref": [
      "r194"
     ],
     "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",
        "negatedLabel": "Gross Unrealized (Losses)"
       }
      }
     },
     "localname": "AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Securities, Available-for-sale [Abstract]",
        "terseLabel": "Available-for-sale",
        "verboseLabel": "Securities available-for-sale:"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]",
        "terseLabel": "Gross Unrealized Losses"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost": {
     "auth_ref": [
      "r199"
     ],
     "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": "Due after five years through ten years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue": {
     "auth_ref": [
      "r195",
      "r199",
      "r547"
     ],
     "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": "Due after five years through ten years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost": {
     "auth_ref": [
      "r198"
     ],
     "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": "Due after one year through five years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue": {
     "auth_ref": [
      "r195",
      "r198",
      "r546"
     ],
     "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": "Due after one year through five years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost": {
     "auth_ref": [
      "r200"
     ],
     "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": "Due after ten years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue": {
     "auth_ref": [
      "r195",
      "r200",
      "r548"
     ],
     "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": "Due after ten years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]",
        "terseLabel": "Available-for-sale, Amortized Cost"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]",
        "terseLabel": "Available-for-sale, Fair Value"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate": {
     "auth_ref": [
      "r195",
      "r201",
      "r549"
     ],
     "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.",
        "label": "Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value",
        "terseLabel": "Total Available-for-sale Securities"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis": {
     "auth_ref": [
      "r195",
      "r201",
      "r544"
     ],
     "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.",
        "label": "Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost",
        "terseLabel": "Total Available-for-sale Securities"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost": {
     "auth_ref": [
      "r197"
     ],
     "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": "Due in one year or less"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue": {
     "auth_ref": [
      "r195",
      "r197",
      "r545"
     ],
     "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": "Due in one year or less"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtSecurities": {
     "auth_ref": [
      "r188",
      "r192",
      "r251",
      "r509"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "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",
        "netLabel": "Securities available-for-sale, at fair value",
        "terseLabel": "Available-for-sale Securities",
        "verboseLabel": "Available-for-sale"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtSecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails",
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AwardTypeAxis": {
     "auth_ref": [
      "r354",
      "r380"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of award under share-based payment arrangement.",
        "label": "Award Type [Axis]"
       }
      }
     },
     "localname": "AwardTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfRestrictedStockAwardsDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BankOwnedLifeInsurance": {
     "auth_ref": [
      "r505"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 9.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The carrying amount of a life insurance policy on an officer, executive or employee for which the reporting entity (a bank) is entitled to proceeds from the policy upon death of the insured or surrender of the insurance policy.",
        "label": "Bank Owned Life Insurance",
        "terseLabel": "Bank owned life insurance"
       }
      }
     },
     "localname": "BankOwnedLifeInsurance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BankOwnedLifeInsuranceIncome": {
     "auth_ref": [
      "r530"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      },
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Earnings on or other increases in the value of the cash surrender value of bank owned life insurance policies.",
        "label": "Bank Owned Life Insurance Income",
        "terseLabel": "Bank owned life insurance"
       }
      }
     },
     "localname": "BankOwnedLifeInsuranceIncome",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BankingRegulationCapitalConservationBufferCommonEquityTierOneRiskBasedCapitalActual": {
     "auth_ref": [
      "r562"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Capital conservation buffer percentage calculated as Common Equity Tier 1 risk-based capital ratio after deduction of minimum Common Equity Tier 1 risk-based capital ratio as defined by regulatory framework.",
        "label": "Banking Regulation, Capital Conservation Buffer, Common Equity Tier One Risk-Based Capital, Actual",
        "terseLabel": "Capital conservation buffer ratio"
       }
      }
     },
     "localname": "BankingRegulationCapitalConservationBufferCommonEquityTierOneRiskBasedCapitalActual",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_BankingRegulationCommonEquityTierOneRiskBasedCapitalRatioCapitalAdequacyMinimum": {
     "auth_ref": [
      "r562",
      "r566"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ratio of minimum Common Equity Tier 1 risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework.",
        "label": "Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Capital Adequacy, Minimum",
        "terseLabel": "Minimum Capital Requirements, Ratio"
       }
      }
     },
     "localname": "BankingRegulationCommonEquityTierOneRiskBasedCapitalRatioCapitalAdequacyMinimum",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_BankingRegulationCommonEquityTierOneRiskBasedCapitalRatioWellCapitalizedMinimum": {
     "auth_ref": [
      "r562"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ratio of minimum Common Equity Tier 1 risk-based capital to risk-weighted assets categorized as well capitalized as defined by regulatory framework for prompt corrective action.",
        "label": "Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Well Capitalized, Minimum",
        "terseLabel": "Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio"
       }
      }
     },
     "localname": "BankingRegulationCommonEquityTierOneRiskBasedCapitalRatioWellCapitalizedMinimum",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_BusinessDescriptionAndAccountingPoliciesTextBlock": {
     "auth_ref": [
      "r95",
      "r140"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for the business description and accounting policies concepts.  Business description describes the nature and type of organization including but not limited to organizational structure as may be applicable to holding companies, parent and subsidiary relationships, business divisions, business units, business segments, affiliates and information about significant ownership of the reporting entity. Accounting policies describe all significant accounting policies of the reporting entity.",
        "label": "Business Description and Accounting Policies [Text Block]",
        "terseLabel": "Nature of Business and Summary of Significant Accounting Policies"
       }
      }
     },
     "localname": "BusinessDescriptionAndAccountingPoliciesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureNatureOfBusinessAndSummaryOfSignificantAccountingPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_Capital": {
     "auth_ref": [
      "r562"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of total capital as defined by regulatory framework.",
        "label": "Banking Regulation, Total Capital, Actual",
        "terseLabel": "Actual, Amount"
       }
      }
     },
     "localname": "Capital",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CapitalAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Banking Regulation, Total Capital [Abstract]",
        "terseLabel": "Total capital (to risk weighted assets)"
       }
      }
     },
     "localname": "CapitalAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CapitalRequiredForCapitalAdequacy": {
     "auth_ref": [
      "r562",
      "r566"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of minimum total risk-based capital required for capital adequacy as defined by regulatory framework.",
        "label": "Banking Regulation, Total Risk-Based Capital, Capital Adequacy, Minimum",
        "terseLabel": "Minimum Capital Requirements, Amount"
       }
      }
     },
     "localname": "CapitalRequiredForCapitalAdequacy",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets": {
     "auth_ref": [
      "r562",
      "r566"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ratio of minimum total risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework.",
        "label": "Banking Regulation, Total Risk-Based Capital Ratio, Capital Adequacy, Minimum",
        "terseLabel": "Minimum Capital Requirements, Ratio"
       }
      }
     },
     "localname": "CapitalRequiredForCapitalAdequacyToRiskWeightedAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_CapitalRequiredToBeWellCapitalized": {
     "auth_ref": [
      "r562"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of minimum total risk-based capital categorized as well capitalized as defined by regulatory framework for prompt corrective action.",
        "label": "Banking Regulation, Total Risk-Based Capital, Well Capitalized, Minimum",
        "terseLabel": "Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount"
       }
      }
     },
     "localname": "CapitalRequiredToBeWellCapitalized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets": {
     "auth_ref": [
      "r562"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ratio of minimum total risk-based capital to risk-weighted assets categorized as well capitalized as defined by regulatory framework for prompt corrective action.",
        "label": "Banking Regulation, Total Risk-Based Capital Ratio, Well Capitalized, Minimum",
        "terseLabel": "Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio"
       }
      }
     },
     "localname": "CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_CapitalToRiskWeightedAssets": {
     "auth_ref": [
      "r562"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ratio of total risk-based capital to risk-weighted assets as defined by regulatory framework.",
        "label": "Banking Regulation, Total Risk-Based Capital Ratio, Actual",
        "terseLabel": "Actual, Ratio"
       }
      }
     },
     "localname": "CapitalToRiskWeightedAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_CarryingReportedAmountFairValueDisclosureMember": {
     "auth_ref": [
      "r443",
      "r444"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measured as reported on the statement of financial position (balance sheet).",
        "label": "Carrying Value"
       }
      }
     },
     "localname": "CarryingReportedAmountFairValueDisclosureMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CashAndCashEquivalentsAtCarryingValue": {
     "auth_ref": [
      "r2",
      "r17",
      "r83"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_Assets",
       "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. 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. Excludes cash and cash equivalents within disposal group and discontinued operation.",
        "label": "Cash and Cash Equivalents, at Carrying Value",
        "totalLabel": "Total cash and cash equivalents"
       }
      }
     },
     "localname": "CashAndCashEquivalentsAtCarryingValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashAndCashEquivalentsFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion 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. 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, Fair Value Disclosure",
        "verboseLabel": "Cash and cash equivalents"
       }
      }
     },
     "localname": "CashAndCashEquivalentsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashAndDueFromBanks": {
     "auth_ref": [
      "r504"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_CashAndCashEquivalentsAtCarryingValue",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "For banks and other depository institutions: Includes cash on hand (currency and coin), cash items in process of collection, noninterest bearing deposits due from other financial institutions (including corporate credit unions), and noninterest bearing balances with the Federal Reserve Banks, Federal Home Loan Banks and central banks.",
        "label": "Cash and Due from Banks",
        "terseLabel": "Cash and due from banks"
       }
      }
     },
     "localname": "CashAndDueFromBanks",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents": {
     "auth_ref": [
      "r76",
      "r83",
      "r86"
     ],
     "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 cash equivalents, end of period",
        "periodStartLabel": "Cash and cash equivalents, beginning of period"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect": {
     "auth_ref": [
      "r76",
      "r446"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "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",
        "totalLabel": "Net decrease in cash and cash equivalents"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashSurrenderValueFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of the amount that could be realized under a life insurance contract or contracts owned by the entity, commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).",
        "label": "Cash Surrender Value, Fair Value Disclosure",
        "verboseLabel": "Bank owned life insurance"
       }
      }
     },
     "localname": "CashSurrenderValueFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ClassOfStockDomain": {
     "auth_ref": [
      "r87",
      "r89",
      "r112",
      "r115",
      "r120",
      "r125",
      "r129",
      "r137",
      "r138",
      "r139",
      "r231",
      "r274",
      "r278",
      "r279",
      "r280",
      "r283",
      "r284",
      "r308",
      "r309",
      "r311",
      "r312",
      "r445",
      "r612"
     ],
     "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]"
       }
      }
     },
     "localname": "ClassOfStockDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CollateralAxis": {
     "auth_ref": [
      "r245"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by category of collateral or no collateral, from lender's perspective.",
        "label": "Collateral Held [Axis]"
       }
      }
     },
     "localname": "CollateralAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CollateralDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Category of collateral or no collateral, from lender's perspective.",
        "label": "Collateral Held [Domain]"
       }
      }
     },
     "localname": "CollateralDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CollateralizedMortgageObligationsMember": {
     "auth_ref": [
      "r271"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The category includes multiclass, pay-through securitizations collateralized by mortgages secured by assets, such as automobiles and boats, which are generally structured so that the collections of principal and interest due from the underlying debtors are paid to the holders of the CMO.",
        "label": "Collateralized Mortgage Obligations [Member]",
        "terseLabel": "Collateralized mortgage obligations"
       }
      }
     },
     "localname": "CollateralizedMortgageObligationsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommercialLoanMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A loan, whether secured or unsecured, to a company for purposes such as seasonal working capital needs, inventory financing, equipment purchases and acquisitions.",
        "label": "Commercial Loan [Member]",
        "terseLabel": "Commercial"
       }
      }
     },
     "localname": "CommercialLoanMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommercialPortfolioSegmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Portfolio segment of the company's total financing receivables related to commercial receivables.",
        "label": "Commercial Portfolio Segment [Member]",
        "terseLabel": "Commercial - Non-Real Estate"
       }
      }
     },
     "localname": "CommercialPortfolioSegmentMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommercialRealEstateMember": {
     "auth_ref": [
      "r247",
      "r341"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Property that is solely used for business purposes.",
        "label": "Commercial Real Estate [Member]",
        "terseLabel": "Commercial Real Estate"
       }
      }
     },
     "localname": "CommercialRealEstateMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommitmentsAndContingencies": {
     "auth_ref": [
      "r24",
      "r266",
      "r515",
      "r577"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 2.0,
       "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"
       }
      }
     },
     "localname": "CommitmentsAndContingencies",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CommitmentsAndContingenciesDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Commitments and Contingencies"
       }
      }
     },
     "localname": "CommitmentsAndContingenciesDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_CommitmentsAndContingenciesDisclosureTextBlock": {
     "auth_ref": [
      "r263",
      "r264",
      "r265",
      "r267",
      "r604"
     ],
     "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.johnmarshallbank.com/role/DisclosureCommitmentsAndContingencies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CommitmentsToExtendCreditMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loan commitments are legally binding commitments to extend credit to a counterparty under certain terms and conditions.",
        "label": "Commitments to Extend Credit [Member]",
        "terseLabel": "Commitments to extend credit"
       }
      }
     },
     "localname": "CommitmentsToExtendCreditMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureCommitmentsAndContingenciesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommonEquityTierOneCapital": {
     "auth_ref": [
      "r562"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of Common Equity Tier 1 risk-based capital as defined by regulatory framework.",
        "label": "Banking Regulation, Common Equity Tier One Risk-Based Capital, Actual",
        "terseLabel": "Actual, Amount"
       }
      }
     },
     "localname": "CommonEquityTierOneCapital",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CommonEquityTierOneCapitalAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Banking Regulation, Common Equity Tier One Risk-Based Capital [Abstract]",
        "terseLabel": "Common equity tier 1 capital (to risk weighted assets)"
       }
      }
     },
     "localname": "CommonEquityTierOneCapitalAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CommonEquityTierOneCapitalRatio": {
     "auth_ref": [
      "r562"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ratio of Common Equity Tier 1 risk-based capital to risk-weighted assets as defined by regulatory framework.",
        "label": "Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual",
        "terseLabel": "Actual, Ratio"
       }
      }
     },
     "localname": "CommonEquityTierOneCapitalRatio",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_CommonEquityTierOneCapitalRequiredForCapitalAdequacy": {
     "auth_ref": [
      "r562",
      "r566"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of minimum Common Equity Tier 1 risk-based capital required for capital adequacy as defined by regulatory framework.",
        "label": "Banking Regulation, Common Equity Tier One Risk-Based Capital, Capital Adequacy, Minimum",
        "terseLabel": "Minimum Capital Requirements, Amount"
       }
      }
     },
     "localname": "CommonEquityTierOneCapitalRequiredForCapitalAdequacy",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CommonEquityTierOneCapitalRequiredToBeWellCapitalized": {
     "auth_ref": [
      "r562"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of minimum Common Equity Tier 1 risk-based capital categorized as well capitalized as defined by regulatory framework for prompt corrective action.",
        "label": "Banking Regulation, Common Equity Tier One Risk-Based Capital, Well Capitalized, Minimum",
        "terseLabel": "Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount"
       }
      }
     },
     "localname": "CommonEquityTierOneCapitalRequiredToBeWellCapitalized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CommonStockCapitalSharesReservedForFutureIssuance": {
     "auth_ref": [
      "r25"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate number of common shares reserved for future issuance.",
        "label": "Common Stock, Capital Shares Reserved for Future Issuance",
        "terseLabel": "Number of shares reserved for issuance"
       }
      }
     },
     "localname": "CommonStockCapitalSharesReservedForFutureIssuance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockDividendsPerShareCashPaid": {
     "auth_ref": [
      "r319"
     ],
     "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": "Dividend paid per share"
       }
      }
     },
     "localname": "CommonStockDividendsPerShareCashPaid",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquityParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_CommonStockMember": {
     "auth_ref": [
      "r96",
      "r97",
      "r428"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Stock that is subordinate to all other stock of the issuer.",
        "label": "Common Stock [Member]",
        "terseLabel": "Common Stock"
       }
      }
     },
     "localname": "CommonStockMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommonStockParOrStatedValuePerShare": {
     "auth_ref": [
      "r10"
     ],
     "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": "Common stock, par value (in dollars per share)"
       }
      }
     },
     "localname": "CommonStockParOrStatedValuePerShare",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_CommonStockSharesAuthorized": {
     "auth_ref": [
      "r10"
     ],
     "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": "Common stock, authorized (in shares)"
       }
      }
     },
     "localname": "CommonStockSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockSharesIssued": {
     "auth_ref": [
      "r10"
     ],
     "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": "Common stock, issued (in shares)"
       }
      }
     },
     "localname": "CommonStockSharesIssued",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockSharesOutstanding": {
     "auth_ref": [
      "r10",
      "r314"
     ],
     "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",
        "terseLabel": "Common stock, outstanding (in shares)"
       }
      }
     },
     "localname": "CommonStockSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockValue": {
     "auth_ref": [
      "r10",
      "r467"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 2.0,
       "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 stock"
       }
      }
     },
     "localname": "CommonStockValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ComprehensiveIncomeNetOfTax": {
     "auth_ref": [
      "r41",
      "r43",
      "r44",
      "r53",
      "r522",
      "r581"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "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",
        "totalLabel": "Total comprehensive income (loss)"
       }
      }
     },
     "localname": "ComprehensiveIncomeNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ComprehensiveIncomeNoteTextBlock": {
     "auth_ref": [
      "r52",
      "r62",
      "r521",
      "r580"
     ],
     "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.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLoss"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ConstructionLoansMember": {
     "auth_ref": [
      "r601"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A borrowing arrangement which provides the entity constructing a facility (such as a building and a landfill) with funds to effect construction, generally on a draw down, or as needed, basis.",
        "label": "Construction Loans [Member]",
        "terseLabel": "Construction and land development"
       }
      }
     },
     "localname": "ConstructionLoansMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ConsumerLoanMember": {
     "auth_ref": [
      "r249"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loan or extension of credit for personal, family, or household use excluding real estate.",
        "label": "Consumer Loan [Member]",
        "terseLabel": "Consumer"
       }
      }
     },
     "localname": "ConsumerLoanMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ConsumerPortfolioSegmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Portfolio segment of the company's total financing receivables related to consumer receivables.",
        "label": "Consumer Portfolio Segment [Member]",
        "terseLabel": "Consumer - Non-Real Estate"
       }
      }
     },
     "localname": "ConsumerPortfolioSegmentMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "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 bonds"
       }
      }
     },
     "localname": "CorporateBondSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CurrentIncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r90",
      "r397",
      "r404",
      "r406"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesProvisionForIncomeTaxesDetailss": {
       "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)",
        "terseLabel": "Current tax expense"
       }
      }
     },
     "localname": "CurrentIncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesProvisionForIncomeTaxesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtAndEquitySecuritiesGainLoss": {
     "auth_ref": [
      "r55",
      "r57"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of unrealized and realized gain (loss) on investment in debt and equity securities.",
        "label": "Debt and Equity Securities, Gain (Loss)",
        "terseLabel": "Gain (loss) on fair value of adjustment on equity securities"
       }
      }
     },
     "localname": "DebtAndEquitySecuritiesGainLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "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 points"
       }
      }
     },
     "localname": "DebtInstrumentBasisSpreadOnVariableRate1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DebtInstrumentFaceAmount": {
     "auth_ref": [
      "r285",
      "r304",
      "r305",
      "r456",
      "r458",
      "r459"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Face (par) amount of debt instrument at time of issuance.",
        "label": "Debt Instrument, Face Amount",
        "verboseLabel": "Face amount or Principal amount"
       }
      }
     },
     "localname": "DebtInstrumentFaceAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtInstrumentInterestRateStatedPercentage": {
     "auth_ref": [
      "r22",
      "r286"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Contractual interest rate for funds borrowed, under the debt agreement.",
        "label": "Debt Instrument, Interest Rate, Stated Percentage",
        "terseLabel": "Stated Interest Rates"
       }
      }
     },
     "localname": "DebtInstrumentInterestRateStatedPercentage",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsLongTermDebtDetails"
     ],
     "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"
       }
      }
     },
     "localname": "DebtInstrumentLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsLongTermDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtInstrumentTable": {
     "auth_ref": [
      "r23",
      "r88",
      "r94",
      "r285",
      "r286",
      "r287",
      "r288",
      "r289",
      "r290",
      "r291",
      "r292",
      "r293",
      "r294",
      "r295",
      "r296",
      "r297",
      "r298",
      "r299",
      "r300",
      "r301",
      "r302",
      "r304",
      "r305",
      "r306",
      "r307",
      "r315",
      "r316",
      "r317",
      "r318",
      "r455",
      "r456",
      "r458",
      "r459",
      "r558"
     ],
     "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]"
       }
      }
     },
     "localname": "DebtInstrumentTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsLongTermDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostAfterAllowanceForCreditLoss": {
     "auth_ref": [
      "r196"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortized cost, after allowance for credit loss, 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, after Allowance for Credit Loss",
        "terseLabel": "Amortized Cost"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleAmortizedCostAfterAllowanceForCreditLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger": {
     "auth_ref": [
      "r221",
      "r255",
      "r258"
     ],
     "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), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.",
        "label": "Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer",
        "terseLabel": "Fair Value, 12 Months or Longer"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss": {
     "auth_ref": [
      "r221",
      "r255"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.",
        "label": "Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss",
        "negatedLabel": "Gross Unrealized Losses, 12 Months or Longer"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months": {
     "auth_ref": [
      "r221",
      "r255",
      "r258"
     ],
     "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), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.",
        "label": "Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months",
        "terseLabel": "Fair Value, Less than 12 Months"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss": {
     "auth_ref": [
      "r221",
      "r255"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.",
        "label": "Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss",
        "negatedLabel": "Gross Unrealized Losses, Less than 12 Months"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleRealizedGain": {
     "auth_ref": [
      "r222"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of realized gain 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, Realized Gain",
        "terseLabel": "Gross gains of available-for-sale debt securities"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleRealizedGain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss": {
     "auth_ref": [
      "r222"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of realized gain (loss) 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, Realized Gain (Loss)",
        "terseLabel": "Gain on sales and calls of securities"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleRealizedGainLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLossDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition": {
     "auth_ref": [
      "r218",
      "r252",
      "r258"
     ],
     "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), in unrealized loss position without allowance for credit loss.",
        "label": "Debt Securities, Available-for-sale, Unrealized Loss Position",
        "verboseLabel": "Fair Value"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleUnrealizedLossPosition",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss": {
     "auth_ref": [
      "r219",
      "r253"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.",
        "label": "Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss",
        "negatedLabel": "Gross Unrealized Losses"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss": {
     "auth_ref": [
      "r188",
      "r205",
      "r206",
      "r509"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss",
        "terseLabel": "Amortized Cost"
       }
      }
     },
     "localname": "DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredIncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r81",
      "r90",
      "r398",
      "r404",
      "r405",
      "r406"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesProvisionForIncomeTaxesDetailss": {
       "order": 2.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      },
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 11.0,
       "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 tax expense (benefit)",
        "verboseLabel": "Deferred tax expense (benefit)"
       }
      }
     },
     "localname": "DeferredIncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesProvisionForIncomeTaxesDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DepositLiabilitiesReclassifiedAsLoansReceivable1": {
     "auth_ref": [
      "r554"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of deposits held by the entity that have been reclassified as loan balances receivable, for example, but not limited to, overdrafts receivable.",
        "label": "Deposit Liabilities Reclassified as Loans Receivable",
        "terseLabel": "Overdraft demand deposits reclassified to loans"
       }
      }
     },
     "localname": "DepositLiabilitiesReclassifiedAsLoansReceivable1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DepositLiabilitiesTypeTableTextBlock": {
     "auth_ref": [
      "r627",
      "r628",
      "r629",
      "r630",
      "r631",
      "r632",
      "r633",
      "r634",
      "r635",
      "r636",
      "r637",
      "r638",
      "r639",
      "r640",
      "r641"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of type of deposit liability.",
        "label": "Deposit Liabilities, Type [Table Text Block]",
        "terseLabel": "Schedule of deposits"
       }
      }
     },
     "localname": "DepositLiabilitiesTypeTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_Deposits": {
     "auth_ref": [
      "r511"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.",
        "label": "Deposits",
        "terseLabel": "Total deposits",
        "totalLabel": "Total deposits"
       }
      }
     },
     "localname": "Deposits",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsDepositsDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DepositsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Deposits [Abstract]",
        "terseLabel": "Deposits:"
       }
      }
     },
     "localname": "DepositsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DepositsByTypeAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Deposits, by Type [Abstract]",
        "terseLabel": "Deposits:"
       }
      }
     },
     "localname": "DepositsByTypeAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsDepositsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DepositsFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.",
        "label": "Deposits, Fair Value Disclosure",
        "verboseLabel": "Deposits"
       }
      }
     },
     "localname": "DepositsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DepositsSavingsDeposits": {
     "auth_ref": [
      "r511"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_Deposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest bearing deposits with no stated maturity, which may include passbook and statement savings accounts and money-market deposit accounts (MMDAs).",
        "label": "Deposits, Savings Deposits",
        "terseLabel": "Savings deposits"
       }
      }
     },
     "localname": "DepositsSavingsDeposits",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsDepositsDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_Depreciation": {
     "auth_ref": [
      "r81",
      "r259"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "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.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "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"
       }
      }
     },
     "localname": "DisaggregationOfRevenueLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DisaggregationOfRevenueTable": {
     "auth_ref": [
      "r330",
      "r332",
      "r333",
      "r334",
      "r335",
      "r336",
      "r337",
      "r338"
     ],
     "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]"
       }
      }
     },
     "localname": "DisaggregationOfRevenueTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DisaggregationOfRevenueTableTextBlock": {
     "auth_ref": [
      "r330"
     ],
     "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 components of non-interest income"
       }
      }
     },
     "localname": "DisaggregationOfRevenueTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock": {
     "auth_ref": [
      "r390"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for share-based payment arrangement.",
        "label": "Share-based Payment Arrangement [Text Block]",
        "terseLabel": "Stock Based Compensation Plan"
       }
      }
     },
     "localname": "DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlan"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Stock Based Compensation Plan"
       }
      }
     },
     "localname": "DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_DividendIncomeOperating": {
     "auth_ref": [
      "r533"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 4.0,
       "parentTag": "us-gaap_InterestAndDividendIncomeOperating",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of operating dividend income on securities.",
        "label": "Dividend Income, Operating",
        "terseLabel": "Dividends"
       }
      }
     },
     "localname": "DividendIncomeOperating",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DividendsCommonStock": {
     "auth_ref": [
      "r319",
      "r553"
     ],
     "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",
        "negatedLabel": "Dividend declared on common stock ($0.20 per share)"
       }
      }
     },
     "localname": "DividendsCommonStock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EarningsPerShareAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Earnings per Common Share"
       }
      }
     },
     "localname": "EarningsPerShareAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_EarningsPerShareBasic": {
     "auth_ref": [
      "r54",
      "r101",
      "r102",
      "r103",
      "r104",
      "r105",
      "r109",
      "r112",
      "r125",
      "r128",
      "r129",
      "r133",
      "r134",
      "r429",
      "r430",
      "r523",
      "r582"
     ],
     "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": "Earnings per share, basic",
        "verboseLabel": "Earnings per common share - basic"
       }
      }
     },
     "localname": "EarningsPerShareBasic",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_EarningsPerShareBasicAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Earnings Per Share, Basic [Abstract]",
        "terseLabel": "Earnings per common share - basic:"
       }
      }
     },
     "localname": "EarningsPerShareBasicAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EarningsPerShareDiluted": {
     "auth_ref": [
      "r54",
      "r101",
      "r102",
      "r103",
      "r104",
      "r105",
      "r112",
      "r125",
      "r128",
      "r129",
      "r133",
      "r134",
      "r429",
      "r430",
      "r523",
      "r582"
     ],
     "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": "Earnings per share, diluted",
        "verboseLabel": "Earnings per common share - diluted"
       }
      }
     },
     "localname": "EarningsPerShareDiluted",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_EarningsPerShareDilutedAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Earnings Per Share, Diluted [Abstract]",
        "terseLabel": "Earnings per common share - diluted:"
       }
      }
     },
     "localname": "EarningsPerShareDilutedAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EarningsPerShareTextBlock": {
     "auth_ref": [
      "r130",
      "r131",
      "r132",
      "r135"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for earnings per share.",
        "label": "Earnings Per Share [Text Block]",
        "terseLabel": "Earnings per Common Share"
       }
      }
     },
     "localname": "EarningsPerShareTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShare"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount": {
     "auth_ref": [
      "r389",
      "r393"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to expense for award under share-based payment arrangement. Excludes expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.",
        "label": "Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-based Payment Arrangement, Amount",
        "terseLabel": "Excess tax benefit on share-based compensation"
       }
      }
     },
     "localname": "EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized": {
     "auth_ref": [
      "r379"
     ],
     "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": "Unrecognized share-based compensation expense"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1": {
     "auth_ref": [
      "r379"
     ],
     "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": "Recognition period"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_EmployeeStockOptionMember": {
     "auth_ref": [
      "r377"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share-based payment arrangement granting right, subject to vesting and other restrictions, to purchase or sell certain number of shares at predetermined price for specified period of time.",
        "label": "Share-based Payment Arrangement, Option [Member]",
        "terseLabel": "Stock options"
       }
      }
     },
     "localname": "EmployeeStockOptionMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EquipmentExpense": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 3.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This element represents equipment expense including depreciation, repairs, rentals, and service contract costs. This item also includes equipment purchases which do not qualify for capitalization in accordance with the entity's accounting policy. This item may also include furniture expenses.",
        "label": "Equipment Expense",
        "terseLabel": "Furniture and equipment expenses"
       }
      }
     },
     "localname": "EquipmentExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EquityComponentDomain": {
     "auth_ref": [
      "r0",
      "r45",
      "r46",
      "r47",
      "r96",
      "r97",
      "r98",
      "r100",
      "r106",
      "r108",
      "r136",
      "r234",
      "r314",
      "r319",
      "r382",
      "r383",
      "r384",
      "r400",
      "r401",
      "r428",
      "r447",
      "r448",
      "r449",
      "r450",
      "r451",
      "r453",
      "r589",
      "r590",
      "r591",
      "r644"
     ],
     "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]"
       }
      }
     },
     "localname": "EquityComponentDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLossDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent": {
     "auth_ref": [
      "r440"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 5.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "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).",
        "label": "Equity Securities, FV-NI",
        "netLabel": "Equity securities, at fair value",
        "terseLabel": "Equity securities, at fair value",
        "verboseLabel": "Equity securities with readily determinable fair values"
       }
      }
     },
     "localname": "EquitySecuritiesFvNiCurrentAndNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails",
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EquitySecuritiesFvNiRealizedGain": {
     "auth_ref": [
      "r229"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of realized gain from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).",
        "label": "Equity Securities, FV-NI, Realized Gain",
        "terseLabel": "Gain on investments"
       }
      }
     },
     "localname": "EquitySecuritiesFvNiRealizedGain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EquitySecuritiesFvNiRealizedLoss": {
     "auth_ref": [
      "r229"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of realized loss from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).",
        "label": "Equity Securities, FV-NI, Realized Loss",
        "negatedLabel": "Loss on investment"
       }
      }
     },
     "localname": "EquitySecuritiesFvNiRealizedLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EstimateOfFairValueFairValueDisclosureMember": {
     "auth_ref": [
      "r294",
      "r304",
      "r305",
      "r442"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measured as an estimate of fair value.",
        "label": "Fair Value"
       }
      }
     },
     "localname": "EstimateOfFairValueFairValueDisclosureMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "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]"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable": {
     "auth_ref": [
      "r431",
      "r432",
      "r433",
      "r437"
     ],
     "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]"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems": {
     "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, Balance Sheet Grouping, Financial Statement Captions [Line Items]"
       }
      }
     },
     "localname": "FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByBalanceSheetGroupingTable": {
     "auth_ref": [
      "r431",
      "r443",
      "r444"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about 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]"
       }
      }
     },
     "localname": "FairValueByBalanceSheetGroupingTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByBalanceSheetGroupingTextBlock": {
     "auth_ref": [
      "r431",
      "r443"
     ],
     "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": "Summary of carrying value and estimated fair value of financial instruments"
       }
      }
     },
     "localname": "FairValueByBalanceSheetGroupingTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueByFairValueHierarchyLevelAxis": {
     "auth_ref": [
      "r294",
      "r304",
      "r305",
      "r341",
      "r342",
      "r343",
      "r344",
      "r345",
      "r346",
      "r347",
      "r348",
      "r432",
      "r471",
      "r472",
      "r473"
     ],
     "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]"
       }
      }
     },
     "localname": "FairValueByFairValueHierarchyLevelAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails",
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByMeasurementBasisAxis": {
     "auth_ref": [
      "r294",
      "r304",
      "r305",
      "r431",
      "r438"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by measurement basis.",
        "label": "Measurement Basis [Axis]"
       }
      }
     },
     "localname": "FairValueByMeasurementBasisAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByMeasurementFrequencyAxis": {
     "auth_ref": [
      "r431",
      "r432",
      "r434",
      "r435",
      "r439"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by measurement frequency.",
        "label": "Measurement Frequency [Axis]"
       }
      }
     },
     "localname": "FairValueByMeasurementFrequencyAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The face amount of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.",
        "label": "Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability",
        "terseLabel": "Off-balance sheet risks, face amount"
       }
      }
     },
     "localname": "FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureCommitmentsAndContingenciesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Fair Value Measurements"
       }
      }
     },
     "localname": "FairValueDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueDisclosuresTextBlock": {
     "auth_ref": [
      "r436"
     ],
     "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 Measurements"
       }
      }
     },
     "localname": "FairValueDisclosuresTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurements"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueInputsLevel1Member": {
     "auth_ref": [
      "r294",
      "r341",
      "r342",
      "r347",
      "r348",
      "r432",
      "r471"
     ],
     "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": "Fair Value, Inputs, Level 1"
       }
      }
     },
     "localname": "FairValueInputsLevel1Member",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails",
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueInputsLevel2Member": {
     "auth_ref": [
      "r294",
      "r304",
      "r305",
      "r341",
      "r342",
      "r347",
      "r348",
      "r432",
      "r472"
     ],
     "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": "Fair Value, Inputs, Level 2"
       }
      }
     },
     "localname": "FairValueInputsLevel2Member",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails",
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueInputsLevel3Member": {
     "auth_ref": [
      "r294",
      "r304",
      "r305",
      "r341",
      "r342",
      "r343",
      "r344",
      "r345",
      "r346",
      "r347",
      "r348",
      "r432",
      "r473"
     ],
     "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": "Fair Value, Inputs, Level 3"
       }
      }
     },
     "localname": "FairValueInputsLevel3Member",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations": {
     "auth_ref": [
      "r431",
      "r432"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.",
        "label": "Subordinated Debt Obligations, Fair Value Disclosure",
        "verboseLabel": "Subordinated debt"
       }
      }
     },
     "localname": "FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueMeasurementFrequencyDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measurement frequency.",
        "label": "Measurement Frequency [Domain]"
       }
      }
     },
     "localname": "FairValueMeasurementFrequencyDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementsFairValueHierarchyDomain": {
     "auth_ref": [
      "r294",
      "r304",
      "r305",
      "r341",
      "r342",
      "r343",
      "r344",
      "r345",
      "r346",
      "r347",
      "r348",
      "r471",
      "r472",
      "r473"
     ],
     "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]"
       }
      }
     },
     "localname": "FairValueMeasurementsFairValueHierarchyDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails",
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementsRecurringMember": {
     "auth_ref": [
      "r436",
      "r439"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Frequent fair value measurement. Includes, but is not limited to, fair value adjustment for impairment of asset, liability or equity, frequently measured at fair value.",
        "label": "Fair Value, Recurring [Member]",
        "terseLabel": "Fair Value, Recurring"
       }
      }
     },
     "localname": "FairValueMeasurementsRecurringMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueOffBalanceSheetRisksDisclosureInformationLineItems": {
     "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, Off-balance Sheet Risks, Disclosure Information [Line Items]"
       }
      }
     },
     "localname": "FairValueOffBalanceSheetRisksDisclosureInformationLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureCommitmentsAndContingenciesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FederalDepositInsuranceCorporationPremiumExpense": {
     "auth_ref": [
      "r532"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_OtherNoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of expense for Federal Deposit Insurance Corporation (FDIC) insurance.",
        "label": "Federal Deposit Insurance Corporation Premium Expense",
        "terseLabel": "FDIC insurance"
       }
      }
     },
     "localname": "FederalDepositInsuranceCorporationPremiumExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FederalFundsPurchasedMember": {
     "auth_ref": [
      "r512"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Short term borrowing where a bank borrows, at the federal funds rate, from another bank.",
        "label": "Federal Funds"
       }
      }
     },
     "localname": "FederalFundsPurchasedMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1": {
     "auth_ref": [
      "r556",
      "r557"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the collateral pledged in support of federal home loan bank advances outstanding.",
        "label": "Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged",
        "terseLabel": "Total collateral under the blanket lien"
       }
      }
     },
     "localname": "FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FederalHomeLoanBankAdvancesMember": {
     "auth_ref": [
      "r512"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Borrowings from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and also in times of liquidity shortages. The member institution executes a promissory note, which is generally collateralized by government securities to the Federal Reserve or loans.",
        "label": "Federal Home Loan Bank Advances [Member]",
        "terseLabel": "FHLB advances"
       }
      }
     },
     "localname": "FederalHomeLoanBankAdvancesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsLongTermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FederalHomeLoanBankBorrowingsFairValueDisclosure": {
     "auth_ref": [
      "r512"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).",
        "label": "Federal Home Loan Bank Borrowings, Fair Value Disclosure",
        "verboseLabel": "FHLB advances"
       }
      }
     },
     "localname": "FederalHomeLoanBankBorrowingsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FederalHomeLoanBankStock": {
     "auth_ref": [
      "r551"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesCarryingAmountOfRestrictedSecuritiesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_RestrictedInvestments",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).",
        "label": "Federal Home Loan Bank Stock",
        "terseLabel": "Federal Home Loan Bank Stock"
       }
      }
     },
     "localname": "FederalHomeLoanBankStock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesCarryingAmountOfRestrictedSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FederalReserveBankAdvancesMember": {
     "auth_ref": [
      "r512"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Borrowings from the Federal Reserve Bank, which are primarily used to cover shortages in the required reserve balance and also in times of liquidity shortages.",
        "label": "Federal Reserve Bank Advances [Member]",
        "terseLabel": "Federal reserve bank advances"
       }
      }
     },
     "localname": "FederalReserveBankAdvancesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FederalReserveBankStock": {
     "auth_ref": [
      "r551"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesCarryingAmountOfRestrictedSecuritiesDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_RestrictedInvestments",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Federal Reserve Bank stock represents an equity interest in the Federal Reserve Bank. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).",
        "label": "Federal Reserve Bank Stock",
        "terseLabel": "Federal Reserve Bank Stock"
       }
      }
     },
     "localname": "FederalReserveBankStock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesCarryingAmountOfRestrictedSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancialInstrumentAxis": {
     "auth_ref": [
      "r210",
      "r213",
      "r226",
      "r227",
      "r228",
      "r236",
      "r238",
      "r239",
      "r240",
      "r241",
      "r254",
      "r256",
      "r257",
      "r258",
      "r302",
      "r313",
      "r427",
      "r468",
      "r469",
      "r470",
      "r471",
      "r472",
      "r473",
      "r474",
      "r475",
      "r476",
      "r477",
      "r478",
      "r479",
      "r480",
      "r481",
      "r483",
      "r484",
      "r485",
      "r486",
      "r487",
      "r488",
      "r489",
      "r490",
      "r491",
      "r492",
      "r493",
      "r494",
      "r495",
      "r496",
      "r497",
      "r498",
      "r612",
      "r613",
      "r614",
      "r615",
      "r616",
      "r617",
      "r618"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of financial instrument.",
        "label": "Financial Instrument [Axis]"
       }
      }
     },
     "localname": "FinancialInstrumentAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureCommitmentsAndContingenciesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]",
        "terseLabel": "Assets:"
       }
      }
     },
     "localname": "FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]",
        "verboseLabel": "Liabilities:"
       }
      }
     },
     "localname": "FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment": {
     "auth_ref": [
      "r164"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_LoansAndLeasesReceivableAllowance",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.",
        "label": "Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment",
        "terseLabel": "Collectively evaluated for impairment"
       }
      }
     },
     "localname": "FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems": {
     "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": "Financing Receivable, Allowance for Credit Loss [Line Items]",
        "terseLabel": "Financing receivable, allowance for credit loss"
       }
      }
     },
     "localname": "FinancingReceivableAllowanceForCreditLossesLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment": {
     "auth_ref": [
      "r165"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_LoansAndLeasesReceivableGrossCarryingAmount",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The balance of financing receivables that were collectively evaluated for impairment.",
        "label": "Financing Receivable, Collectively Evaluated for Impairment",
        "terseLabel": "Collectively evaluated for impairment"
       }
      }
     },
     "localname": "FinancingReceivableCollectivelyEvaluatedForImpairment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableCreditQualityIndicatorsTableTextBlock": {
     "auth_ref": [
      "r173",
      "r241"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of financing receivables by credit quality indicator. The credit quality indicator is a statistic about the credit quality of financing receivables. Examples include, but not limited to, consumer credit risk scores, credit-rating-agency ratings, an entity's internal credit risk grades, loan-to-value ratios, collateral, collection experience and other internal metrics.",
        "label": "Financing Receivable Credit Quality Indicators [Table Text Block]",
        "terseLabel": "Schedule of credit quality information"
       }
      }
     },
     "localname": "FinancingReceivableCreditQualityIndicatorsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FinancingReceivableImpairedLineItems": {
     "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": "Financing Receivable, Impaired [Line Items]"
       }
      }
     },
     "localname": "FinancingReceivableImpairedLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesImpairedLoansDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment": {
     "auth_ref": [
      "r165"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_LoansAndLeasesReceivableGrossCarryingAmount",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The balance of financing receivables that were individually evaluated for impairment.",
        "label": "Financing Receivable, Individually Evaluated for Impairment",
        "terseLabel": "Individually evaluated for impairment"
       }
      }
     },
     "localname": "FinancingReceivableIndividuallyEvaluatedForImpairment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableModificationsRecordedInvestment": {
     "auth_ref": [
      "r175",
      "r186"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of financing receivable modified as troubled debt restructuring.",
        "label": "Financing Receivable, Troubled Debt Restructuring",
        "terseLabel": "Recorded investment in TDR's"
       }
      }
     },
     "localname": "FinancingReceivableModificationsRecordedInvestment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1": {
     "auth_ref": [
      "r176"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.",
        "label": "Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts"
       }
      }
     },
     "localname": "FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "us-gaap_FinancingReceivablePortfolioSegmentAxis": {
     "auth_ref": [
      "r236",
      "r238",
      "r242",
      "r612",
      "r613",
      "r614",
      "r615",
      "r616",
      "r617",
      "r618",
      "r620",
      "r621",
      "r622",
      "r623",
      "r624",
      "r625",
      "r626"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by the level at which an entity develops and documents a systematic methodology to determine its allowance for credit losses.",
        "label": "Financing Receivable Portfolio Segment [Axis]"
       }
      }
     },
     "localname": "FinancingReceivablePortfolioSegmentAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesImpairedLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivablePortfolioSegmentDomain": {
     "auth_ref": [
      "r612",
      "r613",
      "r614",
      "r615",
      "r616",
      "r617",
      "r618",
      "r620",
      "r621",
      "r622",
      "r623",
      "r624",
      "r625",
      "r626"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Level at which an entity develops and documents a systematic methodology to determine its allowance for credit losses.",
        "label": "Financing Receivable Portfolio Segment [Domain]"
       }
      }
     },
     "localname": "FinancingReceivablePortfolioSegmentDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesImpairedLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis": {
     "auth_ref": [
      "r174",
      "r179",
      "r180",
      "r239",
      "r240",
      "r241",
      "r243",
      "r244",
      "r249",
      "r250",
      "r612",
      "r613",
      "r614",
      "r615",
      "r616",
      "r617",
      "r618",
      "r620",
      "r621",
      "r622",
      "r623",
      "r624",
      "r625",
      "r626"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by class of financing receivable determined on the basis of initial measurement attribute, risk characteristics and method of monitoring and assessing credit risk.",
        "label": "Class of Financing Receivable [Axis]"
       }
      }
     },
     "localname": "FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesImpairedLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain": {
     "auth_ref": [
      "r612",
      "r613",
      "r614",
      "r615",
      "r616",
      "r617",
      "r618",
      "r620",
      "r621",
      "r622",
      "r623",
      "r624",
      "r625",
      "r626"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financing receivables determined on the basis of initial measurement attribute, risk characteristics and method of monitoring and assessing credit risk.",
        "label": "Class of Financing Receivable [Domain]"
       }
      }
     },
     "localname": "FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesImpairedLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FinancingReceivableRecordedInvestmentLineItems": {
     "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": "Financing Receivable, Credit Quality Indicator [Line Items]",
        "verboseLabel": "Financing receivable, credit quality indicator"
       }
      }
     },
     "localname": "FinancingReceivableRecordedInvestmentLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems": {
     "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": "Financing Receivable, Past Due [Line Items]",
        "terseLabel": "Financing receivable, past due"
       }
      }
     },
     "localname": "FinancingReceivableRecordedInvestmentPastDueLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_GainLossOnInvestments": {
     "auth_ref": [
      "r61",
      "r81",
      "r190"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      },
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 4.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of realized and unrealized gain (loss) on investment.",
        "label": "Gain (Loss) on Investments",
        "terseLabel": "Gains on securities",
        "verboseLabel": "Gains on securities"
       }
      }
     },
     "localname": "GainLossOnInvestments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GainLossOnSaleOfInvestments": {
     "auth_ref": [
      "r81"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 10.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The net realized gain (loss) on investments sold during the period, not including gains (losses) on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, which, for cash flow reporting, is a component of proceeds from investing activities.",
        "label": "Gain (Loss) on Sale of Investments",
        "negatedLabel": "Gains on sales and calls of available-for-sale securities"
       }
      }
     },
     "localname": "GainLossOnSaleOfInvestments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GainLossOnSaleOfPropertyPlantEquipment": {
     "auth_ref": [
      "r81"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      },
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 9.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "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",
        "negatedLabel": "Net (gains) losses on premises and equipment",
        "verboseLabel": "Net gains (losses) on premises and equipment"
       }
      }
     },
     "localname": "GainLossOnSaleOfPropertyPlantEquipment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecurities": {
     "auth_ref": [
      "r180",
      "r202",
      "r235",
      "r239"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss",
        "terseLabel": "Securities held-to-maturity, fair value of $81,765 and $103,258 as of September 30, 2022 and December 31, 2021, respectively"
       }
      }
     },
     "localname": "HeldToMaturitySecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Securities, Held-to-Maturity, Fair Value to Amortized Cost, after Allowance for Credit Loss [Abstract]",
        "terseLabel": "Held-to-maturity"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss": {
     "auth_ref": [
      "r204",
      "r212"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss",
        "negatedLabel": "Gross Unrealized (Losses)"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss": {
     "auth_ref": [
      "r219",
      "r221"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for 12 months or longer.",
        "label": "Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss",
        "negatedLabel": "Gross Unrealized Losses, 12 Months or Longer"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss": {
     "auth_ref": [
      "r219"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.",
        "label": "Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss",
        "negatedLabel": "Gross Unrealized Losses"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss [Abstract]",
        "terseLabel": "Gross Unrealized Losses"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue": {
     "auth_ref": [
      "r218"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.",
        "label": "Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value",
        "verboseLabel": "Fair Value"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValueAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value [Abstract]",
        "terseLabel": "Held-to-maturity, Fair Value"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValueAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss": {
     "auth_ref": [
      "r219",
      "r221"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for less than 12 months.",
        "label": "Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss",
        "negatedLabel": "Gross Unrealized Losses, Less than 12 Months"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue": {
     "auth_ref": [
      "r221"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (held-to-maturity), in continuous unrealized loss position for less than 12 months.",
        "label": "Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value",
        "terseLabel": "Fair Value, Less than 12 Months"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue": {
     "auth_ref": [
      "r221"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (held-to-maturity), in continuous unrealized loss position for 12 months or longer.",
        "label": "Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value",
        "terseLabel": "Fair Value, 12 Months or Longer"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue": {
     "auth_ref": [
      "r208",
      "r215",
      "r542",
      "r547"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (held-to-maturity), 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, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10",
        "terseLabel": "Due after five years through ten years"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount": {
     "auth_ref": [
      "r208",
      "r542"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) 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, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year Five through Ten",
        "terseLabel": "Due after five years through ten years"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue": {
     "auth_ref": [
      "r207",
      "r214",
      "r541",
      "r546"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (held-to-maturity), 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, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five",
        "terseLabel": "Due after one year through five years"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount": {
     "auth_ref": [
      "r207",
      "r541"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) 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, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year One through Five",
        "terseLabel": "Due after one year through five years"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue": {
     "auth_ref": [
      "r209",
      "r216",
      "r543",
      "r548"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (held-to-maturity), 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, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10",
        "terseLabel": "Due after ten years"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount": {
     "auth_ref": [
      "r209",
      "r543"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) 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, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year 10",
        "terseLabel": "Due after ten years"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesFairValueAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract]",
        "terseLabel": "Held-to-maturity, Fair Value"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesDebtMaturitiesFairValueAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesNetCarryingAmountAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity [Abstract]",
        "terseLabel": "Held-to-maturity, Amortized Cost"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesDebtMaturitiesNetCarryingAmountAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis": {
     "auth_ref": [
      "r206",
      "r544"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date.",
        "label": "Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date",
        "terseLabel": "Total Held-to-maturity Securities"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue": {
     "auth_ref": [
      "r206",
      "r217",
      "r544",
      "r549"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date.",
        "label": "Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Fair Value",
        "terseLabel": "Total Held-to-maturity Securities"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesContractualMaturitiesOfInvestmentSecuritiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesFairValue": {
     "auth_ref": [
      "r203",
      "r211",
      "r509"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-maturity, Fair Value",
        "terseLabel": "Securities held-to-maturity, fair value",
        "verboseLabel": "Held-to-maturity Securities"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesRestricted": {
     "auth_ref": [
      "r482",
      "r596",
      "r602",
      "r603"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of restricted investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-maturity, Restricted",
        "terseLabel": "Held-to-maturity"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesRestricted",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment": {
     "auth_ref": [
      "r169",
      "r172"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.",
        "label": "Impaired Financing Receivable, Average Recorded Investment",
        "terseLabel": "Average Recorded Investment"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableAverageRecordedInvestment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesImpairedLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod": {
     "auth_ref": [
      "r170"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.",
        "label": "Impaired Financing Receivable, Interest Income, Accrual Method",
        "terseLabel": "Interest Income Recognized"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableInterestIncomeAccrualMethod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesImpairedLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableRecordedInvestment": {
     "auth_ref": [
      "r167"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.",
        "label": "Impaired Financing Receivable, Recorded Investment",
        "terseLabel": "Impaired loan balance",
        "verboseLabel": "Total Recorded Investment"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableRecordedInvestment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesImpairedLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance": {
     "auth_ref": [
      "r168"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.",
        "label": "Impaired Financing Receivable, Unpaid Principal Balance",
        "terseLabel": "Unpaid Principal Balance"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableUnpaidPrincipalBalance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesImpairedLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment": {
     "auth_ref": [
      "r167"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.",
        "label": "Impaired Financing Receivable, with No Related Allowance, Recorded Investment",
        "terseLabel": "Recorded Investment with No Allowances"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesImpairedLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivablesTableTextBlock": {
     "auth_ref": [
      "r171"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of impaired financing receivables.",
        "label": "Impaired Financing Receivables [Table Text Block]",
        "terseLabel": "Schedule of impaired loans"
       }
      }
     },
     "localname": "ImpairedFinancingReceivablesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest": {
     "auth_ref": [
      "r50",
      "r145",
      "r147",
      "r150",
      "r153",
      "r155",
      "r501",
      "r519",
      "r539",
      "r583"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.",
        "label": "Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest",
        "totalLabel": "Income before income taxes"
       }
      }
     },
     "localname": "IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeStatementAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Consolidated Statements of Income"
       }
      }
     },
     "localname": "IncomeStatementAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementLocationAxis": {
     "auth_ref": [
      "r261",
      "r262"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by location in the income statement.",
        "label": "Income Statement Location [Axis]"
       }
      }
     },
     "localname": "IncomeStatementLocationAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementLocationDomain": {
     "auth_ref": [
      "r262"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Location in the income statement.",
        "label": "Income Statement Location [Domain]"
       }
      }
     },
     "localname": "IncomeStatementLocationDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_IncomeTaxDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Income Taxes"
       }
      }
     },
     "localname": "IncomeTaxDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxDisclosureTextBlock": {
     "auth_ref": [
      "r91",
      "r394",
      "r395",
      "r396",
      "r402",
      "r407",
      "r409",
      "r410",
      "r411"
     ],
     "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.johnmarshallbank.com/role/DisclosureIncomeTaxes"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_IncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r92",
      "r107",
      "r108",
      "r144",
      "r392",
      "r403",
      "r408",
      "r584"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesProvisionForIncomeTaxesDetailss": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "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)",
        "terseLabel": "Income tax expense",
        "totalLabel": "Total Income Tax Expense",
        "verboseLabel": "Total"
       }
      }
     },
     "localname": "IncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesIncomeTaxRateReconciliationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesProvisionForIncomeTaxesDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Effective Income Tax Rate Reconciliation, Amount [Abstract]",
        "terseLabel": "Effective income tax rate reconciliation, amount"
       }
      }
     },
     "localname": "IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate": {
     "auth_ref": [
      "r393"
     ],
     "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",
        "verboseLabel": "Computed \"expected\" tax expense"
       }
      }
     },
     "localname": "IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationNondeductibleExpenseLifeInsurance": {
     "auth_ref": [
      "r393"
     ],
     "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 life insurance expense.",
        "label": "Effective Income Tax Rate Reconciliation, Nondeductible Expense, Life Insurance, Amount",
        "negatedLabel": "Bank-owned life insurance"
       }
      }
     },
     "localname": "IncomeTaxReconciliationNondeductibleExpenseLifeInsurance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationOtherAdjustments": {
     "auth_ref": [
      "r393"
     ],
     "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.johnmarshallbank.com/role/DisclosureIncomeTaxesIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes": {
     "auth_ref": [
      "r393"
     ],
     "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 benefit"
       }
      }
     },
     "localname": "IncomeTaxReconciliationStateAndLocalIncomeTaxes",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationTaxExemptIncome": {
     "auth_ref": [
      "r393"
     ],
     "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 income (loss) exempt from income taxes.",
        "label": "Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount",
        "terseLabel": "Tax-exempt interest income"
       }
      }
     },
     "localname": "IncomeTaxReconciliationTaxExemptIncome",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesIncomeTaxRateReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxesPaid": {
     "auth_ref": [
      "r78",
      "r85"
     ],
     "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.",
        "label": "Income Taxes Paid",
        "terseLabel": "Income taxes"
       }
      }
     },
     "localname": "IncomeTaxesPaid",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet": {
     "auth_ref": [
      "r80"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 13.0,
       "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 borrowers for interest payments.",
        "label": "Increase (Decrease) in Accrued Interest Receivable, Net",
        "negatedLabel": "Decrease in accrued interest receivable"
       }
      }
     },
     "localname": "IncreaseDecreaseInAccruedInterestReceivableNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInDeposits": {
     "auth_ref": [
      "r84",
      "r538"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The net cash inflow or outflow for the increase (decrease) in the beginning and end of period deposits balances.",
        "label": "Increase (Decrease) in Deposits",
        "terseLabel": "Net increase in deposits"
       }
      }
     },
     "localname": "IncreaseDecreaseInDeposits",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInInterestPayableNet": {
     "auth_ref": [
      "r80"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 15.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in interest payable, which represents the amount owed to note holders, bond holders, and other parties for interest earned on loans or credit extended to the reporting entity.",
        "label": "Increase (Decrease) in Interest Payable, Net",
        "terseLabel": "Decrease in accrued interest payable"
       }
      }
     },
     "localname": "IncreaseDecreaseInInterestPayableNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInOperatingCapitalAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Increase (Decrease) in Operating Capital [Abstract]",
        "terseLabel": "Changes in assets and liabilities:"
       }
      }
     },
     "localname": "IncreaseDecreaseInOperatingCapitalAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncreaseDecreaseInOtherOperatingAssets": {
     "auth_ref": [
      "r80"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 14.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in operating assets classified as other.",
        "label": "Increase (Decrease) in Other Operating Assets",
        "negatedLabel": "Increase in other assets"
       }
      }
     },
     "localname": "IncreaseDecreaseInOtherOperatingAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInOtherOperatingLiabilities": {
     "auth_ref": [
      "r80"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 16.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in operating liabilities classified as other.",
        "label": "Increase (Decrease) in Other Operating Liabilities",
        "terseLabel": "Increase (decrease) in other liabilities"
       }
      }
     },
     "localname": "IncreaseDecreaseInOtherOperatingLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncrementalCommonSharesAttributableToAcceleratedShareRepurchaseAgreements": {
     "auth_ref": [
      "r113",
      "r114",
      "r129",
      "r320"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of accelerated share repurchase agreements.  An accelerated share repurchase program is a combination of transactions that permits an entity to purchase a targeted number of shares immediately with the final purchase price of those shares determined by an average market price over a fixed period of time.",
        "label": "Incremental Common Shares Attributable to Dilutive Effect of Accelerated Share Repurchase Agreements",
        "terseLabel": "Plus: Effect of dilutive options"
       }
      }
     },
     "localname": "IncrementalCommonSharesAttributableToAcceleratedShareRepurchaseAgreements",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_InterestAndDividendIncomeOperating": {
     "auth_ref": [
      "r525"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_InterestIncomeExpenseNet",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the total of interest and dividend income, including any amortization and accretion (as applicable) of discounts and premiums, earned from (1) loans and leases whether held-for-sale or held-in-portfolio; (2) investment securities; (3) federal funds sold; (4) securities purchased under agreements to resell; (5) investments in banker's acceptances, commercial paper, or certificates of deposit; (6) dividend income; or (7) other investments not otherwise specified herein.",
        "label": "Interest and Dividend Income, Operating",
        "totalLabel": "Total interest and dividend income"
       }
      }
     },
     "localname": "InterestAndDividendIncomeOperating",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestAndDividendIncomeOperatingAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Interest and Dividend Income, Operating [Abstract]",
        "terseLabel": "Interest and Dividend Income"
       }
      }
     },
     "localname": "InterestAndDividendIncomeOperatingAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_InterestAndFeeIncomeLoansAndLeases": {
     "auth_ref": [
      "r524"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_InterestAndDividendIncomeOperating",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate interest and fee income generated by: (1) loans the Entity has positive intent and ability to hold for the foreseeable future, or until maturity or payoff, including commercial and consumer loans, whether domestic or foreign, which may consist of: (a) industrial and agricultural; (b) real estate; and (c) real estate construction loans; (d) trade financing; (e) lease financing; (f) home equity lines-of-credit; (g) automobile and other vehicle loans; and (h) credit card and other revolving-type loans and (2) loans and leases held-for-sale which may include mortgage loans, direct financing, and sales-type leases.",
        "label": "Interest and Fee Income, Loans and Leases",
        "terseLabel": "Interest and fees on loans"
       }
      }
     },
     "localname": "InterestAndFeeIncomeLoansAndLeases",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestBearingDepositLiabilities": {
     "auth_ref": [
      "r511"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_Deposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate of all domestic and foreign interest-bearing deposit liabilities.",
        "label": "Interest-bearing Deposit Liabilities",
        "terseLabel": "Interest-bearing demand deposits"
       }
      }
     },
     "localname": "InterestBearingDepositLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsDepositsDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestBearingDepositsInBanks": {
     "auth_ref": [
      "r503",
      "r516"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_CashAndCashEquivalentsAtCarryingValue",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "For banks and other depository institutions (including Federal Reserve Banks, if applicable): Interest-bearing deposits in other financial institutions for relatively short periods of time including, for example, certificates of deposits, which are presented separately from cash on the balance sheet.",
        "label": "Interest-bearing Deposits in Banks and Other Financial Institutions",
        "terseLabel": "Interest-bearing deposits in banks"
       }
      }
     },
     "localname": "InterestBearingDepositsInBanks",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestBearingDomesticDepositBrokered": {
     "auth_ref": [
      "r511"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest-bearing domestic third-party deposits placed by or through the assistance of a deposit broker, also known as brokered deposit liabilities.",
        "label": "Interest-bearing Domestic Deposit, Brokered",
        "terseLabel": "Brokered deposits"
       }
      }
     },
     "localname": "InterestBearingDomesticDepositBrokered",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestExpense": {
     "auth_ref": [
      "r49",
      "r143",
      "r454",
      "r457",
      "r537"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_InterestIncomeExpenseNet",
       "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",
        "totalLabel": "Total interest expense"
       }
      }
     },
     "localname": "InterestExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestExpenseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Interest Expense [Abstract]",
        "terseLabel": "Interest Expense"
       }
      }
     },
     "localname": "InterestExpenseAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_InterestExpenseDeposits": {
     "auth_ref": [
      "r535"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_InterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate amount of interest expense on all deposits.",
        "label": "Interest Expense, Deposits",
        "terseLabel": "Deposits"
       }
      }
     },
     "localname": "InterestExpenseDeposits",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesShortTerm": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_InterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Interest expense incurred during the reporting period on short-term borrowings associated with Federal Home Loan Bank and Federal Reserve Bank advances.",
        "label": "Interest Expense, Federal Home Loan Bank and Federal Reserve Bank Advances, Short-term",
        "terseLabel": "Federal Home Loan Bank advances"
       }
      }
     },
     "localname": "InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesShortTerm",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestExpenseSubordinatedNotesAndDebentures": {
     "auth_ref": [
      "r536"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 3.0,
       "parentTag": "us-gaap_InterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Interest expense incurred during the reporting period on subordinated notes and debentures. Includes amortization of expenses incurred in the issuance of subordinated notes and debentures.",
        "label": "Interest Expense, Subordinated Notes and Debentures",
        "terseLabel": "Subordinated debt"
       }
      }
     },
     "localname": "InterestExpenseSubordinatedNotesAndDebentures",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestIncomeDepositsWithFinancialInstitutions": {
     "auth_ref": [
      "r534",
      "r612",
      "r613"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 5.0,
       "parentTag": "us-gaap_InterestAndDividendIncomeOperating",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Interest income derived from funds deposited with both domestic and foreign financial institutions including funds in money market and other accounts.",
        "label": "Interest Income, Deposits with Financial Institutions",
        "terseLabel": "Interest on deposits in banks"
       }
      }
     },
     "localname": "InterestIncomeDepositsWithFinancialInstitutions",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss": {
     "auth_ref": [
      "r528"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest income or expense, including any amortization and accretion (as applicable) of discounts and premiums, including consideration of the provisions for loan, lease, credit, and other related losses.",
        "label": "Interest Income (Expense), after Provision for Loan Loss",
        "totalLabel": "Net interest income after provision for loan losses"
       }
      }
     },
     "localname": "InterestIncomeExpenseAfterProvisionForLoanLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestIncomeExpenseNet": {
     "auth_ref": [
      "r526"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The net amount of operating interest income (expense).",
        "label": "Interest Income (Expense), Net",
        "totalLabel": "Net interest income"
       }
      }
     },
     "localname": "InterestIncomeExpenseNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestIncomeSecuritiesTaxExempt": {
     "auth_ref": [
      "r533",
      "r612",
      "r613"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 3.0,
       "parentTag": "us-gaap_InterestAndDividendIncomeOperating",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of operating interest income, including amortization and accretion of premiums and discounts, on securities exempt from state, federal and other income tax.",
        "label": "Interest Income, Securities, Operating, Tax Exempt",
        "terseLabel": "Interest on investment securities, tax-exempt"
       }
      }
     },
     "localname": "InterestIncomeSecuritiesTaxExempt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestIncomeSecuritiesTaxable": {
     "auth_ref": [
      "r533",
      "r612",
      "r613"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_InterestAndDividendIncomeOperating",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of operating interest income, including amortization and accretion of premiums and discounts, on securities subject to state, federal and other income tax.",
        "label": "Interest Income, Securities, Operating, Taxable",
        "terseLabel": "Interest on investment securities, taxable"
       }
      }
     },
     "localname": "InterestIncomeSecuritiesTaxable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestPaidNet": {
     "auth_ref": [
      "r72",
      "r77",
      "r85"
     ],
     "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"
       }
      }
     },
     "localname": "InterestPaidNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestPayableCurrentAndNoncurrent": {
     "auth_ref": [
      "r513",
      "r578"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest payable on debt, including, but not limited to, trade payables.",
        "label": "Interest Payable",
        "terseLabel": "Accrued interest payable"
       }
      }
     },
     "localname": "InterestPayableCurrentAndNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestReceivable": {
     "auth_ref": [
      "r28"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 8.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.",
        "label": "Interest Receivable",
        "terseLabel": "Accrued interest receivable"
       }
      }
     },
     "localname": "InterestReceivable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InternalCreditAssessmentAxis": {
     "auth_ref": [
      "r173",
      "r241",
      "r248",
      "r249",
      "r269",
      "r425"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by entity-defined rating.",
        "label": "Internal Credit Assessment [Axis]"
       }
      }
     },
     "localname": "InternalCreditAssessmentAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_InternalCreditAssessmentDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Entity defined credit risk rating.",
        "label": "Internal Credit Assessment [Domain]"
       }
      }
     },
     "localname": "InternalCreditAssessmentDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InvestmentBankingRevenue": {
     "auth_ref": [
      "r529"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Includes (1) underwriting revenue (the spread between the resale price received and the cost of the securities and related expenses) generated through the purchasing, distributing and reselling of new issues of securities (alternatively, could be a secondary offering of a large block of previously issued securities); and (2) fees earned for mergers, acquisitions, divestitures, restructurings, and other types of financial advisory services.",
        "label": "Investment Banking Revenue",
        "terseLabel": "Service charges on deposit accounts"
       }
      }
     },
     "localname": "InvestmentBankingRevenue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InvestmentTableTextBlock": {
     "auth_ref": [
      "r224",
      "r230",
      "r232",
      "r233"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of investment.",
        "label": "Investment [Table Text Block]",
        "terseLabel": "Summary of amortized cost and fair value of securities held-to-maturity and available-for-sale"
       }
      }
     },
     "localname": "InvestmentTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "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": "Contractual maturities of investment securities"
       }
      }
     },
     "localname": "InvestmentsClassifiedByContractualMaturityDateTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Investment Securities"
       }
      }
     },
     "localname": "InvestmentsDebtAndEquitySecuritiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_InvestmentsFairValueDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Investments, Fair Value Disclosure [Abstract]",
        "verboseLabel": "Securities:"
       }
      }
     },
     "localname": "InvestmentsFairValueDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock": {
     "auth_ref": [
      "r224",
      "r502",
      "r550",
      "r600",
      "r619"
     ],
     "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": "Investment Securities"
       }
      }
     },
     "localname": "InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecurities"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LaborAndRelatedExpense": {
     "auth_ref": [
      "r58"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of expense for salary, wage, profit sharing; incentive and equity-based compensation; and other employee benefit.",
        "label": "Labor and Related Expense",
        "verboseLabel": "Salaries and employee benefits"
       }
      }
     },
     "localname": "LaborAndRelatedExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_Liabilities": {
     "auth_ref": [
      "r21",
      "r89",
      "r149",
      "r231",
      "r274",
      "r275",
      "r276",
      "r278",
      "r279",
      "r280",
      "r281",
      "r282",
      "r283",
      "r284",
      "r416",
      "r421",
      "r422",
      "r445",
      "r465",
      "r466"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.",
        "label": "Liabilities",
        "totalLabel": "Total liabilities"
       }
      }
     },
     "localname": "Liabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Liabilities [Abstract]",
        "terseLabel": "Liabilities"
       }
      }
     },
     "localname": "LiabilitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LiabilitiesAndStockholdersEquity": {
     "auth_ref": [
      "r16",
      "r89",
      "r231",
      "r445",
      "r467",
      "r508",
      "r575"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "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",
        "totalLabel": "Total liabilities and shareholders' equity"
       }
      }
     },
     "localname": "LiabilitiesAndStockholdersEquity",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesAndStockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Liabilities and Equity [Abstract]",
        "terseLabel": "Liabilities and Shareholders' Equity"
       }
      }
     },
     "localname": "LiabilitiesAndStockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LineOfCredit": {
     "auth_ref": [
      "r7",
      "r507",
      "r569"
     ],
     "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": "Line of credit"
       }
      }
     },
     "localname": "LineOfCredit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity": {
     "auth_ref": [
      "r19"
     ],
     "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",
        "terseLabel": "Maximum borrowing capacity"
       }
      }
     },
     "localname": "LineOfCreditFacilityMaximumBorrowingCapacity",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LoansAndLeasesReceivableAllowance": {
     "auth_ref": [
      "r160",
      "r164",
      "r182",
      "r185"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_LoansAndLeasesReceivableNetReportedAmount",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.",
        "label": "Loans and Leases Receivable, Allowance",
        "negatedLabel": "Allowance for loan losses",
        "periodEndLabel": "Ending Balance",
        "periodStartLabel": "Beginning Balance",
        "totalLabel": "Total allowance"
       }
      }
     },
     "localname": "LoansAndLeasesReceivableAllowance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LoansAndLeasesReceivableBeforeFeesGross": {
     "auth_ref": [
      "r159"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before allowance and fees, of loans and leases receivable. Excludes loans and leases covered under loss sharing agreements.",
        "label": "Loans and Leases Receivable, before Fees, Gross",
        "terseLabel": "Total Gross Loans"
       }
      }
     },
     "localname": "LoansAndLeasesReceivableBeforeFeesGross",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LoansAndLeasesReceivableGrossCarryingAmount": {
     "auth_ref": [
      "r159"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.",
        "label": "Loans and Leases Receivable, Gross",
        "totalLabel": "Total loans",
        "verboseLabel": "Total loans"
       }
      }
     },
     "localname": "LoansAndLeasesReceivableGrossCarryingAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome": {
     "auth_ref": [
      "r159",
      "r177"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_LoansAndLeasesReceivableNetReportedAmount",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.",
        "label": "Loans and Leases Receivable, Net of Deferred Income",
        "verboseLabel": "Loans, net of unearned income"
       }
      }
     },
     "localname": "LoansAndLeasesReceivableNetOfDeferredIncome",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LoansAndLeasesReceivableNetReportedAmount": {
     "auth_ref": [
      "r159",
      "r517"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 6.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.",
        "label": "Loans and Leases Receivable, Net Amount",
        "totalLabel": "Net loans"
       }
      }
     },
     "localname": "LoansAndLeasesReceivableNetReportedAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LoansInsuredOrGuaranteedByGovernmentAuthoritiesAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by US and non-US government sponsored enterprise, authority, agency and program guarantees for government insured loans.",
        "label": "Loans Insured or Guaranteed by Government Authorities [Axis]"
       }
      }
     },
     "localname": "LoansInsuredOrGuaranteedByGovernmentAuthoritiesAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LoansInsuredOrGuaranteedByGovernmentAuthoritiesDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Guarantee by US and non-US government sponsored enterprises, authorities, agencies and programs for government insured loans.",
        "label": "Loans Insured or Guaranteed by Government Authorities [Domain]"
       }
      }
     },
     "localname": "LoansInsuredOrGuaranteedByGovernmentAuthoritiesDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LoansNotesTradeAndOtherReceivablesDisclosureTextBlock": {
     "auth_ref": [
      "r183"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for claims held for amounts due a entity, excluding financing receivables. Examples include, but are not limited to, trade accounts receivables, notes receivables, loans receivables. Includes disclosure for allowance for credit losses.",
        "label": "Loans, Notes, Trade and Other Receivables Disclosure [Text Block]",
        "terseLabel": "Allowance for Loan Losses"
       }
      }
     },
     "localname": "LoansNotesTradeAndOtherReceivablesDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLosses"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LoansNotesTradeAndOtherReceivablesExcludingAllowanceForCreditLossesTextBlock": {
     "auth_ref": [
      "r183"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for claims held for amounts due a company, excluding disclosure for allowance for credit losses. Examples include, but are not limited to, trade accounts receivables, notes receivables, loans receivables. Also excludes disclosure for financing receivables.",
        "label": "Loans, Notes, Trade and Other Receivables, Excluding Allowance for Credit Losses [Text Block]",
        "terseLabel": "Loans"
       }
      }
     },
     "localname": "LoansNotesTradeAndOtherReceivablesExcludingAllowanceForCreditLossesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureLoans"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LoansPledgedAsCollateral": {
     "auth_ref": [
      "r178",
      "r481"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.",
        "label": "Loans Pledged as Collateral",
        "terseLabel": "Loans pledged"
       }
      }
     },
     "localname": "LoansPledgedAsCollateral",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LoansReceivableFairValueDisclosure": {
     "auth_ref": [
      "r183"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.",
        "label": "Loans Receivable, Fair Value Disclosure",
        "verboseLabel": "Loans, net of unearned income"
       }
      }
     },
     "localname": "LoansReceivableFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LoansReceivableMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "An amount of money or property, or a portion thereof, leant to a borrower (debtor) in exchange for a promise to repay the amount borrowed plus interest at a date certain in the future.",
        "label": "Loans Receivable [Member]",
        "terseLabel": "PPP loans"
       }
      }
     },
     "localname": "LoansReceivableMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LongTermDebt": {
     "auth_ref": [
      "r7",
      "r293",
      "r303",
      "r304",
      "r305",
      "r507",
      "r572"
     ],
     "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": "Carrying Value"
       }
      }
     },
     "localname": "LongTermDebt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsLongTermDebtDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongtermDebtTypeAxis": {
     "auth_ref": [
      "r23"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of long-term debt.",
        "label": "Long-term Debt, Type [Axis]"
       }
      }
     },
     "localname": "LongtermDebtTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsLongTermDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LongtermDebtTypeDomain": {
     "auth_ref": [
      "r23",
      "r273"
     ],
     "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]"
       }
      }
     },
     "localname": "LongtermDebtTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsLongTermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LongtermDebtWeightedAverageInterestRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average interest rate of long-term debt outstanding calculated at point in time.",
        "label": "Long-term Debt, Weighted Average Interest Rate, at Point in Time",
        "terseLabel": "Weighted-Average Interest Rate"
       }
      }
     },
     "localname": "LongtermDebtWeightedAverageInterestRate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsLongTermDebtDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_MarketableSecuritiesLineItems": {
     "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": "Marketable Securities [Line Items]"
       }
      }
     },
     "localname": "MarketableSecuritiesLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_MarketableSecuritiesTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about investment in marketable security.",
        "label": "Marketable Securities [Table]"
       }
      }
     },
     "localname": "MarketableSecuritiesTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_MortgageBackedSecuritiesMember": {
     "auth_ref": [
      "r191",
      "r341",
      "r342",
      "r348",
      "r595"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Securities collateralized by mortgage loans.",
        "label": "Collateralized Mortgage Backed Securities [Member]",
        "terseLabel": "Mortgage-backed"
       }
      }
     },
     "localname": "MortgageBackedSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "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 Securities"
       }
      }
     },
     "localname": "MunicipalBondsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_NetCashProvidedByUsedInFinancingActivities": {
     "auth_ref": [
      "r76"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "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 provided by financing activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInFinancingActivities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Cash Provided by (Used in) Financing Activities [Abstract]",
        "terseLabel": "Cash Flows from Financing Activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInFinancingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInInvestingActivities": {
     "auth_ref": [
      "r76"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
       "weight": 1.0
      }
     },
     "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 (used in) investing activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInInvestingActivities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Cash Provided by (Used in) Investing Activities [Abstract]",
        "terseLabel": "Cash Flows from Investing Activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInInvestingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInOperatingActivities": {
     "auth_ref": [
      "r76",
      "r79",
      "r82"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
       "weight": 1.0
      }
     },
     "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 provided by operating activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInOperatingActivities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Cash Provided by (Used in) Operating Activities [Abstract]",
        "terseLabel": "Cash Flows from Operating Activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetIncomeLoss": {
     "auth_ref": [
      "r1",
      "r39",
      "r42",
      "r47",
      "r51",
      "r82",
      "r89",
      "r99",
      "r101",
      "r102",
      "r103",
      "r104",
      "r107",
      "r108",
      "r122",
      "r145",
      "r147",
      "r150",
      "r153",
      "r155",
      "r231",
      "r274",
      "r275",
      "r276",
      "r278",
      "r279",
      "r280",
      "r281",
      "r282",
      "r283",
      "r284",
      "r430",
      "r445",
      "r520",
      "r579"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 1.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax",
       "weight": 1.0
      },
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "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",
        "verboseLabel": "Net income"
       }
      }
     },
     "localname": "NetIncomeLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic": {
     "auth_ref": [
      "r101",
      "r102",
      "r103",
      "r104",
      "r109",
      "r110",
      "r124",
      "r129",
      "r145",
      "r147",
      "r150",
      "r153",
      "r155"
     ],
     "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 available to common shareholders"
       }
      }
     },
     "localname": "NetIncomeLossAvailableToCommonStockholdersBasic",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted": {
     "auth_ref": [
      "r111",
      "r116",
      "r117",
      "r118",
      "r119",
      "r124",
      "r129"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities, and addition from assumption of issuance of common shares for dilutive potential common shares; of income (loss) available to common shareholders.",
        "label": "Net Income (Loss) Available to Common Stockholders, Diluted",
        "terseLabel": "Net income available to common shareholders"
       }
      }
     },
     "localname": "NetIncomeLossAvailableToCommonStockholdersDiluted",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetIncomeLossAvailableToCommonStockholdersOperationsBasicAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Income (Loss) Available to Common Stockholders, Operations, Basic [Abstract]",
        "terseLabel": "Income available to common shareholders (in thousands):"
       }
      }
     },
     "localname": "NetIncomeLossAvailableToCommonStockholdersOperationsBasicAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetIncomeLossAvailableToCommonStockholdersOperationsDilutedAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Income (Loss) Available to Common Stockholders, Operations, Diluted [Abstract]",
        "terseLabel": "Income available to common shareholders (in thousands):"
       }
      }
     },
     "localname": "NetIncomeLossAvailableToCommonStockholdersOperationsDilutedAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "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": "Recent Accounting Pronouncements"
       }
      }
     },
     "localname": "NewAccountingPronouncementsPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureNatureOfBusinessAndSummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_NoncashInvestingAndFinancingItemsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Noncash Investing and Financing Items [Abstract]",
        "terseLabel": "Supplemental Disclosures of Noncash Transactions"
       }
      }
     },
     "localname": "NoncashInvestingAndFinancingItemsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NoninterestBearingDepositLiabilities": {
     "auth_ref": [
      "r511"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_Deposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate amount of all domestic and foreign noninterest-bearing deposits liabilities held by the entity.",
        "label": "Noninterest-bearing Deposit Liabilities",
        "terseLabel": "Non-interest bearing demand deposits"
       }
      }
     },
     "localname": "NoninterestBearingDepositLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsDepositsDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NoninterestExpense": {
     "auth_ref": [
      "r532"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 3.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total aggregate amount of all noninterest expense.",
        "label": "Noninterest Expense",
        "totalLabel": "Total non-interest expenses"
       }
      }
     },
     "localname": "NoninterestExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NoninterestExpenseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Noninterest Expense [Abstract]",
        "terseLabel": "Non-interest Expenses"
       }
      }
     },
     "localname": "NoninterestExpenseAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NoninterestExpenseDirectorsFees": {
     "auth_ref": [
      "r532"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_OtherNoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Noninterest expense related to directors' fees which are fees paid by an Entity to its directors. Directors' fees may be paid in addition to salary and other benefits.",
        "label": "Noninterest Expense Directors Fees",
        "terseLabel": "Director costs"
       }
      }
     },
     "localname": "NoninterestExpenseDirectorsFees",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NoninterestIncome": {
     "auth_ref": [
      "r530"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The total amount of noninterest income which may be derived from: (1) fees and commissions; (2) premiums earned; (3) insurance policy charges; (4) the sale or disposal of assets; and (5) other sources not otherwise specified.",
        "label": "Noninterest Income",
        "totalLabel": "Total non-interest income"
       }
      }
     },
     "localname": "NoninterestIncome",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NoninterestIncomeAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Noninterest Income [Abstract]",
        "terseLabel": "Non-interest Income"
       }
      }
     },
     "localname": "NoninterestIncomeAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NontaxableMunicipalNotesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Short-term debt securities issued by state, city or local governments or the agencies operated by state, city or local governments that are not taxable.",
        "label": "Nontaxable Municipal Notes [Member]",
        "terseLabel": "Tax-exempt municipal"
       }
      }
     },
     "localname": "NontaxableMunicipalNotesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock": {
     "auth_ref": [
      "r360"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the changes in outstanding nonvested restricted stock shares.",
        "label": "Nonvested Restricted Stock Shares Activity [Table Text Block]",
        "terseLabel": "Summary of restricted stock awards"
       }
      }
     },
     "localname": "NonvestedRestrictedStockSharesActivityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_OccupancyNet": {
     "auth_ref": [
      "r60",
      "r460",
      "r531"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of net occupancy expense that may include items, such as depreciation of facilities and equipment, lease expenses, property taxes and property and casualty insurance expense.",
        "label": "Occupancy, Net",
        "terseLabel": "Occupancy expense of premises"
       }
      }
     },
     "localname": "OccupancyNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OciDebtSecuritiesAvailableForSaleTransferToHeldToMaturityAdjustmentFromAociForAmortizationOfGainLossAfterTax": {
     "auth_ref": [
      "r36",
      "r187"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 3.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after tax, of adjustment from accumulated other comprehensive income (loss) for amortization of gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) from transfer to investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "OCI, Debt Securities, Available-for-Sale, Transfer to Held-to-Maturity, Adjustment from AOCI for Amortization of Gain (Loss), after Tax",
        "negatedLabel": "Amortization of unrealized gains on securities transferred to held-to-maturity, net of tax of $(10) and $(8) for the three months ended September 30, 2022 and September 30, 2021, respectively, net of tax of $(31) and $(8) for the nine months ended September 30, 2022 and September 30, 2021, respectively"
       }
      }
     },
     "localname": "OciDebtSecuritiesAvailableForSaleTransferToHeldToMaturityAdjustmentFromAociForAmortizationOfGainLossAfterTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OciDebtSecuritiesAvailableForSaleTransferToHeldToMaturityAdjustmentFromAociForAmortizationOfGainLossTax": {
     "auth_ref": [
      "r187"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of tax expense (benefit) on adjustment from accumulated other comprehensive income (loss) for amortization of gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) from transfer to investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "OCI, Debt Securities, Available-for-Sale, Transfer to Held-to-Maturity, Adjustment from AOCI for Amortization of Gain (Loss), Tax",
        "terseLabel": "Unrealized gains on securities transferred to held-to-maturity, tax"
       }
      }
     },
     "localname": "OciDebtSecuritiesAvailableForSaleTransferToHeldToMaturityAdjustmentFromAociForAmortizationOfGainLossTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLossParenthetical"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLiability": {
     "auth_ref": [
      "r462"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 5.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "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": "Lease liabilities"
       }
      }
     },
     "localname": "OperatingLeaseLiability",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseRightOfUseAsset": {
     "auth_ref": [
      "r461"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 10.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "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"
       }
      }
     },
     "localname": "OperatingLeaseRightOfUseAsset",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense": {
     "auth_ref": [
      "r81"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of amortization expense for right-of-use asset from operating lease.",
        "label": "Operating Lease, Right-of-Use Asset, Amortization Expense",
        "terseLabel": "Right of use asset amortization"
       }
      }
     },
     "localname": "OperatingLeaseRightOfUseAssetAmortizationExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherAssets": {
     "auth_ref": [
      "r5",
      "r505",
      "r570"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 11.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of assets classified as other.",
        "label": "Other Assets",
        "terseLabel": "Other assets"
       }
      }
     },
     "localname": "OtherAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsNetOfTax": {
     "auth_ref": [
      "r29",
      "r30"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 1.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after tax and before 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), before Adjustment, after Tax",
        "terseLabel": "Unrealized gain (loss) on available-for-sale securities, net of tax of $(3,709) and $23 for the three months ended September 30, 2022 and September 30, 2021, respectively, net of tax of $(8,081) and $(624) for the nine months ended September 30, 2022 and September 30, 2021, respectively"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesBeforeReclassificationAdjustmentsTax": {
     "auth_ref": [
      "r34"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before adjustment, of tax expense (benefit) for 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), before Adjustment, Tax",
        "terseLabel": "Unrealized gain (loss) on available-for-sale securities, tax"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossAvailableForSaleSecuritiesBeforeReclassificationAdjustmentsTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLossParenthetical"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax": {
     "auth_ref": [
      "r29",
      "r30",
      "r34"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after adjustment, of tax expense (benefit) for 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 tax expense (benefit) for 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, Tax",
        "terseLabel": "Gain (loss) on available-for-sale securities, related tax"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLossDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTax": {
     "auth_ref": [
      "r40",
      "r43",
      "r45",
      "r46",
      "r48",
      "r52",
      "r314",
      "r447",
      "r452",
      "r453",
      "r521",
      "r580"
     ],
     "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)",
        "verboseLabel": "Net change during the period"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLossDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent": {
     "auth_ref": [
      "r40",
      "r43",
      "r413",
      "r414",
      "r419"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 2.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax",
       "weight": 1.0
      }
     },
     "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": "Total other comprehensive income (loss)"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]",
        "terseLabel": "Other comprehensive income (loss):"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax": {
     "auth_ref": [
      "r33",
      "r37",
      "r38",
      "r223"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 2.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.",
        "label": "Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax",
        "negatedLabel": "Reclassification adjustment for gains on available-for-sale securities included in net income, net of tax of $(2) for the nine months ended September 30, 2021"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax": {
     "auth_ref": [
      "r34",
      "r223"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.",
        "label": "Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax",
        "terseLabel": "Reclassification adjustment for gains on available-for-sale securities included in net income, tax"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeLossParenthetical"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherCostAndExpenseOperating": {
     "auth_ref": [
      "r59"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails": {
       "order": 7.0,
       "parentTag": "us-gaap_OtherNoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The total amount of other operating cost and expense items that are associated with the entity's normal revenue producing operation.",
        "label": "Other Cost and Expense, Operating",
        "terseLabel": "Other operating expenses"
       }
      }
     },
     "localname": "OtherCostAndExpenseOperating",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherExpensesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Other Operating Expenses"
       }
      }
     },
     "localname": "OtherExpensesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_OtherLiabilities": {
     "auth_ref": [
      "r514"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 6.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of liabilities classified as other.",
        "label": "Other Liabilities",
        "terseLabel": "Other liabilities"
       }
      }
     },
     "localname": "OtherLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherNoninterestExpense": {
     "auth_ref": [
      "r532"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 4.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of noninterest expense classified as other.",
        "label": "Other Noninterest Expense",
        "totalLabel": "Total other operating expenses",
        "verboseLabel": "Other operating expenses"
       }
      }
     },
     "localname": "OtherNoninterestExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherOperatingIncomeAndExpenseTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for other operating income and other operating expense items.",
        "label": "Other Operating Income and Expense [Text Block]",
        "terseLabel": "Other Operating Expenses"
       }
      }
     },
     "localname": "OtherOperatingIncomeAndExpenseTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpenses"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_OtherOperatingIncomeExpenseNet": {
     "auth_ref": [],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 5.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The net amount of other operating income and expenses, the components of which are not separately disclosed on the income statement, from items that are associated with the entity's normal revenue producing operations.",
        "label": "Other Operating Income",
        "terseLabel": "Other operating income (loss)"
       }
      }
     },
     "localname": "OtherOperatingIncomeExpenseNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherRealEstate": {
     "auth_ref": [
      "r510"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Carrying amount of other real estate not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. This does not include real estate assets taken in settlement of troubled loans through surrender or foreclosure.",
        "label": "Other Real Estate",
        "terseLabel": "Other real estate owned"
       }
      }
     },
     "localname": "OtherRealEstate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PassMember": {
     "auth_ref": [
      "r173",
      "r241"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A category of financing receivables not considered to be special mention, substandard, doubtful, and loss receivables.",
        "label": "Pass [Member]",
        "terseLabel": "Pass"
       }
      }
     },
     "localname": "PassMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PastDueFinancingReceivablesTableTextBlock": {
     "auth_ref": [
      "r179",
      "r180",
      "r239",
      "r250"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of aging analysis for financing receivable.",
        "label": "Financing Receivable, Past Due [Table Text Block]",
        "terseLabel": "Schedule of past due and non-accrual loans"
       }
      }
     },
     "localname": "PastDueFinancingReceivablesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_PaymentsOfDividends": {
     "auth_ref": [
      "r70"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.",
        "label": "Payments of Dividends",
        "negatedLabel": "Cash dividends paid"
       }
      }
     },
     "localname": "PaymentsOfDividends",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt": {
     "auth_ref": [
      "r63",
      "r66",
      "r189"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow to acquire investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Payments to Acquire Debt Securities, Available-for-sale",
        "negatedLabel": "Purchase of available-for-sale securities"
       }
      }
     },
     "localname": "PaymentsToAcquireAvailableForSaleSecuritiesDebt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireEquitySecuritiesFvNi": {
     "auth_ref": [
      "r73",
      "r225"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 7.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow to acquire investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as investing activity.",
        "label": "Payments to Acquire Equity Securities, FV-NI",
        "negatedLabel": "Net purchase of equity securities"
       }
      }
     },
     "localname": "PaymentsToAcquireEquitySecuritiesFvNi",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireHeldToMaturitySecurities": {
     "auth_ref": [
      "r66",
      "r189"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow through purchase of long-term held-to-maturity securities.",
        "label": "Payments to Acquire Held-to-maturity Securities",
        "negatedLabel": "Purchase of held-to-maturity securities"
       }
      }
     },
     "localname": "PaymentsToAcquireHeldToMaturitySecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireLoansAndLeasesHeldForInvestment": {
     "auth_ref": [
      "r66"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash outflow from (a) purchases of loans held-for-investment, (b) purchases of leases held-for-investment, and (c) both.",
        "label": "Payments to Acquire Loans and Leases Held-for-investment",
        "negatedLabel": "Net increase in loans"
       }
      }
     },
     "localname": "PaymentsToAcquireLoansAndLeasesHeldForInvestment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquirePropertyPlantAndEquipment": {
     "auth_ref": [
      "r67"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 9.0,
       "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": "Purchases of bank premises and equipment"
       }
      }
     },
     "localname": "PaymentsToAcquirePropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PlanNameAxis": {
     "auth_ref": [
      "r354",
      "r380"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by plan name for share-based payment arrangement.",
        "label": "Plan Name [Axis]"
       }
      }
     },
     "localname": "PlanNameAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PlanNameDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Plan name for share-based payment arrangement.",
        "label": "Plan Name [Domain]"
       }
      }
     },
     "localname": "PlanNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PledgedAssetsSeparatelyReportedSecuritiesPledgedAsCollateralAtFairValue": {
     "auth_ref": [
      "r481"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The sum of the fair values, as of the date of each statement of financial position presented, of securities that are restricted as collateral for the payment of related debt obligations, primarily secured borrowings and repurchase agreements, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them.",
        "label": "Pledged Assets Separately Reported, Securities Pledged as Collateral, at Fair Value",
        "terseLabel": "Pledged securities, market value"
       }
      }
     },
     "localname": "PledgedAssetsSeparatelyReportedSecuritiesPledgedAsCollateralAtFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PortionAtFairValueFairValueDisclosureMember": {
     "auth_ref": [
      "r441"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measured at fair value for financial reporting purposes.",
        "label": "Portion at Fair Value Measurement [Member]"
       }
      }
     },
     "localname": "PortionAtFairValueFairValueDisclosureMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PreferredStockParOrStatedValuePerShare": {
     "auth_ref": [
      "r9",
      "r308"
     ],
     "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.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_PreferredStockSharesAuthorized": {
     "auth_ref": [
      "r9"
     ],
     "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, authorized (in shares)"
       }
      }
     },
     "localname": "PreferredStockSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockSharesIssued": {
     "auth_ref": [
      "r9",
      "r308"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.",
        "label": "Preferred Stock, Shares Issued",
        "terseLabel": "Preferred stock, issued (in shares)"
       }
      }
     },
     "localname": "PreferredStockSharesIssued",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockValue": {
     "auth_ref": [
      "r9",
      "r467"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "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 preferred stock (or preferred stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable preferred shares, par value and other disclosure concepts are in another section within stockholders' equity.",
        "label": "Preferred Stock, Value, Issued",
        "terseLabel": "Preferred stock, par value $0.01 per share; authorized 1,000,000 shares; none issued"
       }
      }
     },
     "localname": "PreferredStockValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromIssuanceOfSubordinatedLongTermDebt": {
     "auth_ref": [
      "r69"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow from a borrowing where a lender is placed in a lien position behind debt having a higher priority of repayment (senior) in liquidation of the entity's assets or underlying collateral.",
        "label": "Proceeds from Issuance of Subordinated Long-term Debt",
        "terseLabel": "Issuance of subordinated debt"
       }
      }
     },
     "localname": "ProceedsFromIssuanceOfSubordinatedLongTermDebt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromLifeInsurancePolicies": {
     "auth_ref": [
      "r65",
      "r75"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 8.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow for proceeds from settlement of corporate-owned life insurance policy, classified as investing activities. Includes, but is not limited to, bank-owned life insurance policy.",
        "label": "Proceeds from Life Insurance Policy",
        "terseLabel": "Insurance casualty proceeds"
       }
      }
     },
     "localname": "ProceedsFromLifeInsurancePolicies",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities": {
     "auth_ref": [
      "r63",
      "r64",
      "r189"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow from maturity, prepayment and call of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-sale",
        "terseLabel": "Proceeds from maturities, calls and principal repayments of available-for-sale securities"
       }
      }
     },
     "localname": "ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities": {
     "auth_ref": [
      "r64",
      "r189"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow associated with the maturity, prepayments and calls (requests for early payments) of debt securities designated as held-to-maturity.",
        "label": "Proceeds from Maturities, Prepayments and Calls of Held-to-maturity Securities",
        "terseLabel": "Proceeds from maturities, calls and principal repayments of held-to-maturity securities"
       }
      }
     },
     "localname": "ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt": {
     "auth_ref": [
      "r63",
      "r64",
      "r189"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Proceeds from Sale of Debt Securities, Available-for-sale",
        "terseLabel": "Proceeds from sales of available-for-sale securities"
       }
      }
     },
     "localname": "ProceedsFromSaleOfAvailableForSaleSecuritiesDebt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromStockOptionsExercised": {
     "auth_ref": [
      "r68",
      "r381"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow from exercise of option under share-based payment arrangement.",
        "label": "Proceeds from Stock Options Exercised",
        "terseLabel": "Issuance of common stock for share options exercised"
       }
      }
     },
     "localname": "ProceedsFromStockOptionsExercised",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProfessionalFees": {
     "auth_ref": [
      "r598",
      "r599"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_OtherNoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A fee charged for services from professionals such as doctors, lawyers and accountants. The term is often expanded to include other professions, for example, pharmacists charging to maintain a medicinal profile of a client or customer.",
        "label": "Professional Fees",
        "terseLabel": "Professional fees"
       }
      }
     },
     "localname": "ProfessionalFees",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProfitLoss": {
     "auth_ref": [
      "r1",
      "r39",
      "r42",
      "r47",
      "r74",
      "r89",
      "r99",
      "r107",
      "r108",
      "r145",
      "r147",
      "r150",
      "r153",
      "r155",
      "r231",
      "r274",
      "r275",
      "r276",
      "r278",
      "r279",
      "r280",
      "r281",
      "r282",
      "r283",
      "r284",
      "r413",
      "r417",
      "r418",
      "r423",
      "r424",
      "r430",
      "r445",
      "r539"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "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"
       }
      }
     },
     "localname": "ProfitLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentNet": {
     "auth_ref": [
      "r3",
      "r4",
      "r260",
      "r467",
      "r552",
      "r576"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 7.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.",
        "label": "Property, Plant and Equipment, Net",
        "terseLabel": "Bank premises and equipment, net"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProvisionForLoanAndLeaseLosses": {
     "auth_ref": [
      "r80",
      "r161",
      "r527"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of expense related to estimated loss from loan and lease transactions.",
        "label": "Provision for Loan and Lease Losses",
        "terseLabel": "Provision for loan losses",
        "verboseLabel": "Provision"
       }
      }
     },
     "localname": "ProvisionForLoanAndLeaseLosses",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProvisionForLoanLossesExpensed": {
     "auth_ref": [
      "r237",
      "r518"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of credit loss expense (reversal of expense) for financing receivable.",
        "label": "Financing Receivable, Credit Loss, Expense (Reversal)",
        "terseLabel": "Provision for loan losses"
       }
      }
     },
     "localname": "ProvisionForLoanLossesExpensed",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ReceivableTypeDomain": {
     "auth_ref": [
      "r27"
     ],
     "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]"
       }
      }
     },
     "localname": "ReceivableTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ReceivablesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Allowance for Loan Losses"
       }
      }
     },
     "localname": "ReceivablesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock": {
     "auth_ref": [
      "r559",
      "r560",
      "r561",
      "r563",
      "r564",
      "r565",
      "r567",
      "r568"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for regulatory capital requirement for depository and lending institutions. Institutions include, but not are not limited to, finance company, insured depository institution, bank holding company, savings and loan association holding company, bank and savings institution not federally insured, mortgage company, foreign financial institution and credit union.",
        "label": "Regulatory Capital Requirements under Banking Regulations [Text Block]",
        "terseLabel": "Regulatory Capital"
       }
      }
     },
     "localname": "RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapital"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_RepaymentsOfFederalHomeLoanBankBorrowings": {
     "auth_ref": [
      "r71"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow for repayment of Federal Home Loan Bank (FHLBank) borrowing, classified as financing activity.",
        "label": "Payments of FHLBank Borrowings, Financing Activities",
        "negatedLabel": "Net repayment of Federal Home Loan Bank advances"
       }
      }
     },
     "localname": "RepaymentsOfFederalHomeLoanBankBorrowings",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RepaymentsOfSubordinatedDebt": {
     "auth_ref": [
      "r71"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash outflow from the repayment of long-term borrowing where a lender is placed in a lien position behind debt having a higher priority of repayment (senior) in case of liquidation of the entity's assets or underlying collateral.",
        "label": "Repayments of Subordinated Debt",
        "negatedLabel": "Repayment of subordinated debt",
        "terseLabel": "Repayment of subordinated debt"
       }
      }
     },
     "localname": "RepaymentsOfSubordinatedDebt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ResidentialRealEstateMember": {
     "auth_ref": [
      "r246",
      "r341"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Property that is used as a home.",
        "label": "Residential Real Estate [Member]",
        "terseLabel": "Residential Real Estate"
       }
      }
     },
     "localname": "ResidentialRealEstateMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesImpairedLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RestrictedInvestments": {
     "auth_ref": [
      "r602",
      "r603"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesCarryingAmountOfRestrictedSecuritiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Investments which are not defined as or included in marketable (debt, equity, or other) securities whose use is restricted in whole or in part, generally by contractual agreements or regulatory requirements. For use in an unclassified balance sheet.",
        "label": "Restricted Investments",
        "terseLabel": "Restricted securities, at cost",
        "totalLabel": "Total Restricted Securities"
       }
      }
     },
     "localname": "RestrictedInvestments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesCarryingAmountOfRestrictedSecuritiesDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RestrictedStockMember": {
     "auth_ref": [
      "r130"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Stock including a provision that prohibits sale or substantive sale of an equity instrument for a specified period of time or until specified performance conditions are met.",
        "label": "Restricted Stock [Member]",
        "terseLabel": "Restricted Stock Awards"
       }
      }
     },
     "localname": "RestrictedStockMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfRestrictedStockAwardsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RetainedEarningsAccumulatedDeficit": {
     "auth_ref": [
      "r12",
      "r319",
      "r385",
      "r467",
      "r574",
      "r592",
      "r594"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 4.0,
       "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"
       }
      }
     },
     "localname": "RetainedEarningsAccumulatedDeficit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RetainedEarningsMember": {
     "auth_ref": [
      "r0",
      "r96",
      "r97",
      "r98",
      "r100",
      "r106",
      "r108",
      "r234",
      "r382",
      "r383",
      "r384",
      "r400",
      "r401",
      "r428",
      "r589",
      "r591"
     ],
     "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.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Revenue"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax": {
     "auth_ref": [
      "r141",
      "r142",
      "r146",
      "r151",
      "r152",
      "r156",
      "r157",
      "r158",
      "r329",
      "r330",
      "r500"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, excluding 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, Excluding Assessed Tax",
        "verboseLabel": "Non-interest income"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerExcludingAssessedTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenueComponentsOfNonInterestIncomeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerTextBlock": {
     "auth_ref": [
      "r321",
      "r322",
      "r323",
      "r324",
      "r325",
      "r326",
      "r327",
      "r328",
      "r331",
      "r339"
     ],
     "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": "Revenue"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRevenue"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability": {
     "auth_ref": [
      "r463",
      "r464"
     ],
     "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 asset obtained in exchange for new operating lease liability"
       }
      }
     },
     "localname": "RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable": {
     "auth_ref": [
      "r27"
     ],
     "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]"
       }
      }
     },
     "localname": "ScheduleOfAccountsNotesLoansAndFinancingReceivableTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock": {
     "auth_ref": [
      "r27"
     ],
     "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": "Schedule of composition of the loan portfolio"
       }
      }
     },
     "localname": "ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureLoansTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock": {
     "auth_ref": [
      "r36",
      "r452",
      "r453"
     ],
     "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": "Schedule of changes in other comprehensive income (loss)"
       }
      }
     },
     "localname": "ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLossTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable": {
     "auth_ref": [
      "r130"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule for securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) in the future that were not included in the computation of diluted EPS because to do so would increase EPS amounts or decrease loss per share amounts for the period presented, by Antidilutive Securities.",
        "label": "Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table]"
       }
      }
     },
     "localname": "ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareAdditionalInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock": {
     "auth_ref": [
      "r562",
      "r566"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the capital amounts and ratios as of the balance sheet date, indicating whether the entity or entities are in compliance with regulatory capital requirements, by entity.",
        "label": "Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]",
        "terseLabel": "Schedule of compliance with regulatory capital requirements under banking regulations"
       }
      }
     },
     "localname": "ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock": {
     "auth_ref": [
      "r399"
     ],
     "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": "Schedule of provision for income taxes"
       }
      }
     },
     "localname": "ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfDebtInstrumentsTextBlock": {
     "auth_ref": [
      "r23",
      "r94",
      "r304",
      "r306",
      "r315",
      "r316",
      "r317",
      "r318",
      "r455",
      "r456",
      "r459",
      "r558"
     ],
     "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 long-term debt"
       }
      }
     },
     "localname": "ScheduleOfDebtInstrumentsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock": {
     "auth_ref": [
      "r129"
     ],
     "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": "Schedule of computation of earnings per share"
       }
      }
     },
     "localname": "ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock": {
     "auth_ref": [
      "r393"
     ],
     "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": "Schedule of income tax rate reconciliation"
       }
      }
     },
     "localname": "ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureIncomeTaxesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock": {
     "auth_ref": [
      "r431",
      "r432"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of assets and liabilities, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date 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 (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3).",
        "label": "Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]",
        "terseLabel": "Summary of fair value of assets measured at fair value on a recurring basis"
       }
      }
     },
     "localname": "ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfFairValueOffBalanceSheetRisksTable": {
     "auth_ref": [
      "r442",
      "r443"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule detailing the information required and determined to be disclosed regarding the fair value of financial assets and financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.",
        "label": "Schedule of Fair Value, Off-balance Sheet Risks [Table]"
       }
      }
     },
     "localname": "ScheduleOfFairValueOffBalanceSheetRisksTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureCommitmentsAndContingenciesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfFairValueOffBalanceSheetRisksTextBlock": {
     "auth_ref": [
      "r442",
      "r443"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined) which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.",
        "label": "Schedule of Fair Value, Off-balance Sheet Risks [Table Text Block]",
        "terseLabel": "Summary of the contract or notional amount of the Company's exposure to off-balance sheet risk"
       }
      }
     },
     "localname": "ScheduleOfFairValueOffBalanceSheetRisksTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureCommitmentsAndContingenciesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable": {
     "auth_ref": [
      "r238",
      "r626"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about allowance for credit loss on financing receivable.",
        "label": "Financing Receivable, Allowance for Credit Loss [Table]"
       }
      }
     },
     "localname": "ScheduleOfFinancingReceivableAllowanceForCreditLossesTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable": {
     "auth_ref": [
      "r241",
      "r249"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about credit quality indicator for financing receivable.",
        "label": "Financing Receivable, Credit Quality Indicator [Table]"
       }
      }
     },
     "localname": "ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfFinancingReceivablesPastDueTable": {
     "auth_ref": [
      "r239",
      "r250"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about aging analysis for financing receivable.",
        "label": "Financing Receivable, Past Due [Table]"
       }
      }
     },
     "localname": "ScheduleOfFinancingReceivablesPastDueTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesPastDueAndNonAccrualLoansDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfImpairedFinancingReceivableTable": {
     "auth_ref": [
      "r171"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule of the recorded investment, unpaid principal balance, associated allowance, average recorded investment, accounting policies, and interest income recognized on the accrual and cash basis for impaired financing receivables by class of financing receivable.",
        "label": "Schedule of Impaired Financing Receivable [Table]"
       }
      }
     },
     "localname": "ScheduleOfImpairedFinancingReceivableTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesImpairedLoansDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfOtherOperatingCostAndExpenseByComponentTextBlock": {
     "auth_ref": [
      "r59"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of each detailed component of other operating costs and expenses that are applicable to sales and revenues, but not included in the cost of sales in the income statement.",
        "label": "Schedule of Other Operating Cost and Expense, by Component [Table Text Block]",
        "terseLabel": "Schedule of components of other operating expenses"
       }
      }
     },
     "localname": "ScheduleOfOtherOperatingCostAndExpenseByComponentTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureOtherOperatingExpensesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable": {
     "auth_ref": [
      "r354",
      "r380"
     ],
     "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]"
       }
      }
     },
     "localname": "ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfRestrictedStockAwardsDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable": {
     "auth_ref": [
      "r380"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Details comprising a table providing supplementary information on outstanding and exercisable share awards as of the balance sheet date which stratifies outstanding options by ranges of exercise prices.",
        "label": "Share-based Payment Arrangement, Option, Exercise Price Range [Table]"
       }
      }
     },
     "localname": "ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock": {
     "auth_ref": [
      "r380"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of option exercise prices, by grouped ranges, including the upper and lower limits of the price range, the number of shares under option, weighted average exercise price and remaining contractual option terms.",
        "label": "Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block]",
        "terseLabel": "Summary of stock options outstanding and exercisable"
       }
      }
     },
     "localname": "ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock": {
     "auth_ref": [
      "r361",
      "r372",
      "r374"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure for stock option plans. Includes, but is not limited to, outstanding awards at beginning and end of year, grants, exercises, forfeitures, and weighted-average grant date fair value.",
        "label": "Share-based Payment Arrangement, Option, Activity [Table Text Block]",
        "terseLabel": "Summary of stock options activity"
       }
      }
     },
     "localname": "ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock": {
     "auth_ref": [
      "r220"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "For all investments in an unrealized loss position, including those for which other-than-temporary impairments have not been recognized in earnings (including investments for which a portion of an other-than-temporary impairment has been recognized in other comprehensive income), a tabular disclosure of the aggregate related fair value of investments with unrealized losses and the aggregate amount of unrealized losses (that is, the amount by which amortized cost basis exceeds fair value).",
        "label": "Schedule of Unrealized Loss on Investments [Table Text Block]",
        "terseLabel": "Schedule of gross unrealized loss position of investments"
       }
      }
     },
     "localname": "ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember": {
     "auth_ref": [
      "r426"
     ],
     "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)"
       }
      }
     },
     "localname": "SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShareBasedCompensation": {
     "auth_ref": [
      "r80"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of noncash expense for share-based payment arrangement.",
        "label": "Share-based Payment Arrangement, Noncash Expense",
        "terseLabel": "Share-based compensation expense"
       }
      }
     },
     "localname": "ShareBasedCompensation",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1": {
     "auth_ref": [
      "r356"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period",
        "terseLabel": "Vesting term"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod": {
     "auth_ref": [
      "r366"
     ],
     "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",
        "negatedLabel": "Nonvested shares, forfeited"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfRestrictedStockAwardsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r371"
     ],
     "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",
        "terseLabel": "Weighted average grant date fair value, forfeited"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfRestrictedStockAwardsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod": {
     "auth_ref": [
      "r369"
     ],
     "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": "Nonvested shares, granted",
        "verboseLabel": "Restricted stock grants"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfRestrictedStockAwardsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r369"
     ],
     "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",
        "terseLabel": "Weighted average grant date fair value, granted"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfRestrictedStockAwardsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber": {
     "auth_ref": [
      "r368"
     ],
     "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",
        "periodEndLabel": "Nonvested shares outstanding, ending balance",
        "periodStartLabel": "Nonvested shares outstanding, beginning balance"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfRestrictedStockAwardsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r368"
     ],
     "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",
        "periodEndLabel": "Weighted average grant date fair value, ending balance",
        "periodStartLabel": "Weighted average grant date fair value outstanding, beginning balance"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfRestrictedStockAwardsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod": {
     "auth_ref": [
      "r370"
     ],
     "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",
        "negatedLabel": "Nonvested shares, vested"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfRestrictedStockAwardsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue": {
     "auth_ref": [
      "r373"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value",
        "terseLabel": "Fair value of vested shares"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r370"
     ],
     "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, vested"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfRestrictedStockAwardsDetails"
     ],
     "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]"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfRestrictedStockAwardsDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized": {
     "auth_ref": [
      "r358"
     ],
     "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": "Number of shares authorized"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant": {
     "auth_ref": [
      "r380"
     ],
     "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": "Number of shares available for grant"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber": {
     "auth_ref": [
      "r364"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number",
        "terseLabel": "Options exercisable"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice": {
     "auth_ref": [
      "r364"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price",
        "terseLabel": "Weighted average exercise price, exercisable"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue": {
     "auth_ref": [
      "r373"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value",
        "terseLabel": "Intrinsic value of options exercised"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod": {
     "auth_ref": [
      "r367"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period",
        "negatedLabel": "Options forfeited or expired"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice": {
     "auth_ref": [
      "r367"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average price of options that were either forfeited or expired.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price",
        "terseLabel": "Weighted average exercise price, forfeited or expired"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Gross number of share options (or share units) granted during the period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross",
        "terseLabel": "Options granted"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue": {
     "auth_ref": [
      "r380"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value",
        "terseLabel": "Aggregate intrinsic value outstanding"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber": {
     "auth_ref": [
      "r363",
      "r380"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of options outstanding, including both vested and non-vested options.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number",
        "periodEndLabel": "Options outstanding, ending balance",
        "periodStartLabel": "Options outstanding, beginning balance",
        "terseLabel": "Options outstanding"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice": {
     "auth_ref": [
      "r362"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price",
        "periodEndLabel": "Weighted average exercise price, ending balance",
        "periodStartLabel": "Weighted average exercise price, beginning balance"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward": {
     "auth_ref": [
      "r355"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Description of terms of award under share-based payment arrangement.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award",
        "terseLabel": "Term of award"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain": {
     "auth_ref": [
      "r352",
      "r359"
     ],
     "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.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfRestrictedStockAwardsDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average price at which option holders acquired shares when converting their stock options into shares.",
        "label": "Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price",
        "terseLabel": "Weighted average exercise price, exercised"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis": {
     "auth_ref": [
      "r376"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by range of option prices pertaining to options granted.",
        "label": "Exercise Price Range [Axis]"
       }
      }
     },
     "localname": "ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain": {
     "auth_ref": [
      "r377"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Supplementary information on outstanding and exercisable share awards as of the balance sheet date which stratifies outstanding options by ranges of exercise prices.",
        "label": "Exercise Price Range [Domain]"
       }
      }
     },
     "localname": "ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems": {
     "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 Payment Arrangement, Option, Exercise Price Range [Line Items]"
       }
      }
     },
     "localname": "ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit": {
     "auth_ref": [
      "r377"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.",
        "label": "Share-based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit",
        "terseLabel": "Exercise price range minimum rate"
       }
      }
     },
     "localname": "ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit": {
     "auth_ref": [
      "r377"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.",
        "label": "Share-based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit",
        "terseLabel": "Exercise price range maximum rate"
       }
      }
     },
     "localname": "ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod": {
     "auth_ref": [
      "r357"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period",
        "terseLabel": "Expiration term"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1": {
     "auth_ref": [
      "r380"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value",
        "terseLabel": "Aggregate intrinsic value exercisable"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1": {
     "auth_ref": [
      "r380"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term",
        "terseLabel": "Options exercisable, weighted average remaining contractual life (in years)"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2": {
     "auth_ref": [
      "r375"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term",
        "terseLabel": "Options outstanding, weighted average remaining contractual life (in years)"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsOutstandingAndExercisableDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Purchase price of common stock expressed as a percentage of its fair value.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent",
        "terseLabel": "Price of stock expressed in fair value percentage"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_SharesOutstanding": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of shares issued which are neither cancelled nor held in the treasury.",
        "label": "Shares, Outstanding",
        "periodEndLabel": "Ending balance (in shares)",
        "periodStartLabel": "Beginning balance (in shares)"
       }
      }
     },
     "localname": "SharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShortTermDebtTypeAxis": {
     "auth_ref": [
      "r20"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of short-term debt arrangement.",
        "label": "Short-term Debt, Type [Axis]"
       }
      }
     },
     "localname": "ShortTermDebtTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShortTermDebtTypeDomain": {
     "auth_ref": [
      "r18"
     ],
     "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]"
       }
      }
     },
     "localname": "ShortTermDebtTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SpecialMentionMember": {
     "auth_ref": [
      "r173",
      "r241"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A category of financing receivables considered to have potential weaknesses that deserve management's close attention. If left uncorrected, those potential weaknesses may result in a deterioration of the repayment prospects for the asset or of the creditor's position at some future date.",
        "label": "Special Mention [Member]",
        "terseLabel": "Special Mention"
       }
      }
     },
     "localname": "SpecialMentionMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_StandbyLettersOfCreditMember": {
     "auth_ref": [
      "r268",
      "r270",
      "r412",
      "r597"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "An irrevocable undertaking (typically by a financial institution) to guarantee payment of a specified financial obligation.",
        "label": "Standby Letters of Credit [Member]",
        "terseLabel": "Standby letters of credit"
       }
      }
     },
     "localname": "StandbyLettersOfCreditMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureCommitmentsAndContingenciesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_StatementClassOfStockAxis": {
     "auth_ref": [
      "r8",
      "r9",
      "r10",
      "r87",
      "r89",
      "r112",
      "r115",
      "r120",
      "r125",
      "r129",
      "r137",
      "r138",
      "r139",
      "r231",
      "r274",
      "r278",
      "r279",
      "r280",
      "r283",
      "r284",
      "r308",
      "r309",
      "r311",
      "r312",
      "r314",
      "r445",
      "r612"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by the different classes of stock of the entity.",
        "label": "Class of Stock [Axis]"
       }
      }
     },
     "localname": "StatementClassOfStockAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementEquityComponentsAxis": {
     "auth_ref": [
      "r0",
      "r26",
      "r45",
      "r46",
      "r47",
      "r96",
      "r97",
      "r98",
      "r100",
      "r106",
      "r108",
      "r136",
      "r234",
      "r314",
      "r319",
      "r382",
      "r383",
      "r384",
      "r400",
      "r401",
      "r428",
      "r447",
      "r448",
      "r449",
      "r450",
      "r451",
      "r453",
      "r589",
      "r590",
      "r591",
      "r644"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by component of equity.",
        "label": "Equity Components [Axis]"
       }
      }
     },
     "localname": "StatementEquityComponentsAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLossDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "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]"
       }
      }
     },
     "localname": "StatementLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfCashFlowsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Consolidated Statements of Cash Flows"
       }
      }
     },
     "localname": "StatementOfCashFlowsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfFinancialPositionAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Consolidated Balance Sheets"
       }
      }
     },
     "localname": "StatementOfFinancialPositionAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Consolidated Statements of Comprehensive Income (Loss)"
       }
      }
     },
     "localname": "StatementOfIncomeAndComprehensiveIncomeAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfStockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Consolidated Statements of Shareholders' Equity"
       }
      }
     },
     "localname": "StatementOfStockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementTable": {
     "auth_ref": [
      "r96",
      "r97",
      "r98",
      "r136",
      "r500"
     ],
     "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]"
       }
      }
     },
     "localname": "StatementTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheetsParenthetical",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited": {
     "auth_ref": [
      "r9",
      "r10",
      "r314",
      "r319"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of shares related to Restricted Stock Award forfeited during the period.",
        "label": "Stock Issued During Period, Shares, Restricted Stock Award, Forfeited",
        "terseLabel": "Restricted stock vesting, shares surrendered"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquityParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures": {
     "auth_ref": [
      "r9",
      "r10",
      "r314",
      "r319"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of shares issued during the period related to Restricted Stock Awards, net of any shares forfeited.",
        "label": "Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures",
        "terseLabel": "Restricted stock vesting (in shares)"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised": {
     "auth_ref": [
      "r9",
      "r10",
      "r314",
      "r319",
      "r365"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of share options (or share units) exercised during the current period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period",
        "negatedLabel": "Options exercised",
        "terseLabel": "Exercise of stock options (in shares)"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesStockOptionsExercised",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureStockBasedCompensationPlanSummaryOfStockOptionsActivityDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised": {
     "auth_ref": [
      "r26",
      "r314",
      "r319"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Value of stock issued as a result of the exercise of stock options.",
        "label": "Stock Issued During Period, Value, Stock Options Exercised",
        "terseLabel": "Exercise of stock options"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueStockOptionsExercised",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockholdersEquity": {
     "auth_ref": [
      "r10",
      "r14",
      "r15",
      "r89",
      "r181",
      "r231",
      "r445",
      "r467"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 3.0,
       "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",
        "totalLabel": "Total shareholders' equity"
       }
      }
     },
     "localname": "StockholdersEquity",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAccumulatedOtherComprehensiveIncomeLossDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfShareholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Stockholders' Equity Attributable to Parent [Abstract]",
        "terseLabel": "Shareholders' Equity"
       }
      }
     },
     "localname": "StockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SubordinatedDebt": {
     "auth_ref": [
      "r6",
      "r7",
      "r507",
      "r572"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets.",
        "label": "Subordinated Debt",
        "terseLabel": "Subordinated debt"
       }
      }
     },
     "localname": "SubordinatedDebt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SubordinatedDebtMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This element represents domestic or foreign subordinated debt. Subordinated debt has a lower priority of repayment in liquidation of the entity's assets.",
        "label": "Subordinated Debt [Member]",
        "terseLabel": "Subordinated debt"
       }
      }
     },
     "localname": "SubordinatedDebtMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsLongTermDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SubstandardMember": {
     "auth_ref": [
      "r173",
      "r241"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A category of financing receivables that are inadequately protected by the current sound worth and paying capacity of the obligor or of the collateral pledged, if any. Loans so classified have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that the creditor will sustain some loss if the deficiencies are not corrected.",
        "label": "Substandard [Member]",
        "terseLabel": "Substandard"
       }
      }
     },
     "localname": "SubstandardMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesScheduleOfCreditQualityInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SupplementalCashFlowInformationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Supplemental Cash Flow Information [Abstract]",
        "terseLabel": "Supplemental Disclosures of Cash Flow Information"
       }
      }
     },
     "localname": "SupplementalCashFlowInformationAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_TaxableMunicipalNotesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Short-term debt securities issued by state, city or local governments or the agencies operated by state, city or local governments that are taxable.",
        "label": "Taxable Municipal Notes [Member]",
        "terseLabel": "Taxable municipal"
       }
      }
     },
     "localname": "TaxableMunicipalNotesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_TierOneLeverageCapital": {
     "auth_ref": [
      "r562"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of Tier 1 leverage capital as defined by regulatory framework.",
        "label": "Banking Regulation, Tier One Leverage Capital, Actual",
        "terseLabel": "Actual, Amount"
       }
      }
     },
     "localname": "TierOneLeverageCapital",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TierOneLeverageCapitalAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Banking Regulation, Tier One Leverage Capital [Abstract]",
        "terseLabel": "Tier 1 capital (to average assets)"
       }
      }
     },
     "localname": "TierOneLeverageCapitalAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy": {
     "auth_ref": [
      "r562",
      "r566"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of minimum Tier 1 leverage capital required for capital adequacy as defined by regulatory framework.",
        "label": "Banking Regulation, Tier One Leverage Capital, Capital Adequacy, Minimum",
        "terseLabel": "Minimum Capital Requirements, Amount"
       }
      }
     },
     "localname": "TierOneLeverageCapitalRequiredForCapitalAdequacy",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets": {
     "auth_ref": [
      "r562",
      "r566"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ratio of minimum Tier 1 leverage capital to average assets required for capital adequacy as defined by regulatory framework.",
        "label": "Banking Regulation, Tier One Leverage Capital Ratio, Capital Adequacy, Minimum",
        "terseLabel": "Minimum Capital Requirements, Ratio"
       }
      }
     },
     "localname": "TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized": {
     "auth_ref": [
      "r562"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of minimum Tier 1 leverage capital categorized as well capitalized as defined by regulatory framework for prompt corrective action.",
        "label": "Banking Regulation, Tier One Leverage Capital, Well Capitalized, Minimum",
        "terseLabel": "Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount"
       }
      }
     },
     "localname": "TierOneLeverageCapitalRequiredToBeWellCapitalized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets": {
     "auth_ref": [
      "r562"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ratio of minimum Tier 1 leverage capital to average assets categorized as well capitalized as defined by regulatory framework for prompt corrective action.",
        "label": "Banking Regulation, Tier One Leverage Capital Ratio, Well Capitalized, Minimum",
        "terseLabel": "Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio"
       }
      }
     },
     "localname": "TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_TierOneLeverageCapitalToAverageAssets": {
     "auth_ref": [
      "r562"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ratio of Tier 1 capital to average assets as defined by regulatory framework.",
        "label": "Banking Regulation, Tier One Leverage Capital Ratio, Actual",
        "terseLabel": "Actual, Ratio"
       }
      }
     },
     "localname": "TierOneLeverageCapitalToAverageAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_TierOneRiskBasedCapital": {
     "auth_ref": [
      "r562"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of Tier 1 risk-based capital as defined by regulatory framework.",
        "label": "Banking Regulation, Tier One Risk-Based Capital, Actual",
        "terseLabel": "Actual, Amount"
       }
      }
     },
     "localname": "TierOneRiskBasedCapital",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TierOneRiskBasedCapitalAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Banking Regulation, Tier One Risk-Based Capital [Abstract]",
        "terseLabel": "Tier 1 capital (to risk weighted assets)"
       }
      }
     },
     "localname": "TierOneRiskBasedCapitalAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized": {
     "auth_ref": [
      "r562"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of minimum Tier 1 risk-based capital categorized as well capitalized as defined by regulatory framework for prompt corrective action.",
        "label": "Banking Regulation, Tier One Risk-Based Capital, Well Capitalized, Minimum",
        "terseLabel": "Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount"
       }
      }
     },
     "localname": "TierOneRiskBasedCapitalRequiredToBeWellCapitalized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets": {
     "auth_ref": [
      "r562"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ratio of minimum Tier 1 risk-based capital to risk-weighted assets categorized as well capitalized as defined by regulatory framework for prompt corrective action.",
        "label": "Banking Regulation, Tier One Risk-Based Capital Ratio, Well Capitalized, Minimum",
        "terseLabel": "Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio"
       }
      }
     },
     "localname": "TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets": {
     "auth_ref": [
      "r562"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ratio of Tier 1 risk-based capital to risk-weighted assets as defined by regulatory framework.",
        "label": "Banking Regulation, Tier One Risk-Based Capital Ratio, Actual",
        "terseLabel": "Actual, Ratio"
       }
      }
     },
     "localname": "TierOneRiskBasedCapitalToRiskWeightedAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureRegulatoryCapitalScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_TimeDepositMaturitiesTableTextBlock": {
     "auth_ref": [
      "r272"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of time deposit liability maturities.",
        "label": "Time Deposit Maturities [Table Text Block]",
        "terseLabel": "Schedule of carrying amount of the time deposits by contractual maturity"
       }
      }
     },
     "localname": "TimeDepositMaturitiesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_TimeDeposits": {
     "auth_ref": [
      "r511",
      "r555"
     ],
     "calculation": {
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_Deposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit liabilities, including certificates of deposit.",
        "label": "Time Deposits",
        "terseLabel": "Time deposits"
       }
      }
     },
     "localname": "TimeDeposits",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsDepositsDetails",
      "http://www.johnmarshallbank.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TimeDepositsByMaturityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Time Deposits, Fiscal Year Maturity [Abstract]",
        "terseLabel": "Contractual maturity"
       }
      }
     },
     "localname": "TimeDepositsByMaturityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsTimeDepositsAndFhlbAdvancesByContractualMaturityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain": {
     "auth_ref": [
      "r210",
      "r213",
      "r226",
      "r227",
      "r228",
      "r302",
      "r313",
      "r427",
      "r468",
      "r469",
      "r470",
      "r471",
      "r472",
      "r473",
      "r474",
      "r475",
      "r476",
      "r477",
      "r478",
      "r479",
      "r480",
      "r481",
      "r483",
      "r484",
      "r485",
      "r486",
      "r487",
      "r488",
      "r489",
      "r490",
      "r491",
      "r492",
      "r493",
      "r494",
      "r495",
      "r496",
      "r497",
      "r498",
      "r612",
      "r613",
      "r614",
      "r615",
      "r616",
      "r617",
      "r618"
     ],
     "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]"
       }
      }
     },
     "localname": "TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureCommitmentsAndContingenciesDetails",
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_USGovernmentAgenciesDebtSecuritiesMember": {
     "auth_ref": [
      "r93",
      "r341",
      "r540"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debentures, notes, and other debt securities issued by US government agencies, for example, but not limited to, Government National Mortgage Association (GNMA or Ginnie Mae). Excludes US treasury securities and debt issued by government-sponsored Enterprises (GSEs), for example, but is not limited to, Federal Home Loan Mortgage Corporation (FHLMC or Freddie Mac), Federal National Mortgage Association (FNMA or Fannie Mae), and the Federal Home Loan Bank (FHLB).",
        "label": "US Government Agencies Debt Securities [Member]",
        "terseLabel": "U.S. government and federal agencies"
       }
      }
     },
     "localname": "USGovernmentAgenciesDebtSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_USTreasurySecuritiesMember": {
     "auth_ref": [
      "r93",
      "r341",
      "r348",
      "r540"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This category includes information about debt securities issued by the United States Department of the Treasury and backed by the United States government. Such securities primarily consist of treasury bills (short-term maturities - one year or less), treasury notes (intermediate term maturities - two to ten years), and treasury bonds (long-term maturities - ten to thirty years).",
        "label": "US Treasury Securities [Member]",
        "terseLabel": "U.S Treasuries"
       }
      }
     },
     "localname": "USTreasurySecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureFairValueMeasurementsFairValueOfAssetsMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAdditionalInformationDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails",
      "http://www.johnmarshallbank.com/role/DisclosureInvestmentSecuritiesFairValueOfSecuritiesHeldToMaturityAndAvailableForSaleDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_UnallocatedFinancingReceivablesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financing receivables that have not been allocated to a portfolio segment.",
        "label": "Unallocated Financing Receivables [Member]",
        "terseLabel": "Unallocated"
       }
      }
     },
     "localname": "UnallocatedFinancingReceivablesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesAllowanceForLoanLossesActivityDetails",
      "http://www.johnmarshallbank.com/role/DisclosureAllowanceForLoanLossesBalanceOfAllowanceForLoanLossesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums": {
     "auth_ref": [
      "r184"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.",
        "label": "Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums",
        "terseLabel": "Net deferred loan costs"
       }
      }
     },
     "localname": "UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic": {
     "auth_ref": [
      "r123",
      "r126",
      "r127"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of undistributed earnings (loss) allocated to participating securities for the basic earnings (loss) per share or per unit calculation under the two-class method.",
        "label": "Undistributed Earnings (Loss) Allocated to Participating Securities, Basic",
        "negatedLabel": "Less: Income attributable to unvested restricted stock awards"
       }
      }
     },
     "localname": "UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesDiluted": {
     "auth_ref": [
      "r121",
      "r123",
      "r126",
      "r127"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of undistributed earnings (loss) allocated to participating securities for the diluted earnings (loss) per share or per unit calculation under the two-class method.",
        "label": "Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted",
        "negatedLabel": "Less: Income attributable to unvested restricted stock awards"
       }
      }
     },
     "localname": "UndistributedEarningsLossAllocatedToParticipatingSecuritiesDiluted",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_VariableRateAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of variable rate.",
        "label": "Variable Rate [Axis]"
       }
      }
     },
     "localname": "VariableRateAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "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]"
       }
      }
     },
     "localname": "VariableRateDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureDepositsAndBorrowingsAdditionalInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding": {
     "auth_ref": [
      "r111",
      "r129"
     ],
     "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": "Weighted-average common shares outstanding - diluted"
       }
      }
     },
     "localname": "WeightedAverageNumberOfDilutedSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Weighted Average Number of Shares Outstanding, Diluted [Abstract]",
        "terseLabel": "Weighted average shares outstanding:"
       }
      }
     },
     "localname": "WeightedAverageNumberOfSharesOutstandingAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_WeightedAverageNumberOfSharesOutstandingBasic": {
     "auth_ref": [
      "r109",
      "r129"
     ],
     "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",
        "terseLabel": "Weighted-average common shares outstanding - basic"
       }
      }
     },
     "localname": "WeightedAverageNumberOfSharesOutstandingBasic",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Weighted Average Number of Shares Outstanding, Basic [Abstract]",
        "terseLabel": "Weighted average shares outstanding:"
       }
      }
     },
     "localname": "WeightedAverageNumberOfSharesOutstandingBasicAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.johnmarshallbank.com/role/DisclosureEarningsPerCommonShareComputationOfEarningsPerShareDetails"
     ],
     "xbrltype": "stringItemType"
    }
   },
   "unitCount": 7
  }
 },
 "std_ref": {
  "r0": {
   "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"
  },
  "r1": {
   "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"
  },
  "r10": {
   "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"
  },
  "r100": {
   "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"
  },
  "r101": {
   "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"
  },
  "r102": {
   "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"
  },
  "r103": {
   "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"
  },
  "r104": {
   "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"
  },
  "r105": {
   "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"
  },
  "r106": {
   "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"
  },
  "r107": {
   "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"
  },
  "r108": {
   "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"
  },
  "r109": {
   "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"
  },
  "r11": {
   "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"
  },
  "r110": {
   "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"
  },
  "r111": {
   "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"
  },
  "r112": {
   "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"
  },
  "r113": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1707-109256"
  },
  "r114": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "23",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1757-109256"
  },
  "r115": {
   "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"
  },
  "r116": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "40",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1930-109256"
  },
  "r117": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "40",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)(1)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1930-109256"
  },
  "r118": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "40",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)(2)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1930-109256"
  },
  "r119": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "40",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)(3)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1930-109256"
  },
  "r12": {
   "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"
  },
  "r120": {
   "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"
  },
  "r121": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e2740-109256"
  },
  "r122": {
   "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"
  },
  "r123": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=SL5780133-109256"
  },
  "r124": {
   "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"
  },
  "r125": {
   "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"
  },
  "r126": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "65",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e2793-109256"
  },
  "r127": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "66",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e2814-109256"
  },
  "r128": {
   "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"
  },
  "r129": {
   "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"
  },
  "r13": {
   "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"
  },
  "r130": {
   "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"
  },
  "r131": {
   "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"
  },
  "r132": {
   "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"
  },
  "r133": {
   "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"
  },
  "r134": {
   "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"
  },
  "r135": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "260",
   "URI": "http://asc.fasb.org/topic&trid=2144383"
  },
  "r136": {
   "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"
  },
  "r137": {
   "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"
  },
  "r138": {
   "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"
  },
  "r139": {
   "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"
  },
  "r14": {
   "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"
  },
  "r140": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "275",
   "URI": "http://asc.fasb.org/topic&trid=2134479"
  },
  "r141": {
   "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"
  },
  "r142": {
   "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"
  },
  "r143": {
   "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"
  },
  "r144": {
   "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"
  },
  "r145": {
   "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"
  },
  "r146": {
   "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"
  },
  "r147": {
   "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"
  },
  "r148": {
   "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"
  },
  "r149": {
   "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"
  },
  "r15": {
   "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"
  },
  "r150": {
   "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"
  },
  "r151": {
   "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"
  },
  "r152": {
   "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"
  },
  "r153": {
   "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"
  },
  "r154": {
   "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"
  },
  "r155": {
   "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"
  },
  "r156": {
   "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"
  },
  "r157": {
   "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"
  },
  "r158": {
   "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"
  },
  "r159": {
   "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"
  },
  "r16": {
   "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"
  },
  "r160": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r161": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r162": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(3)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r163": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(4)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r164": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r165": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r166": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r167": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953550-111524"
  },
  "r168": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(4)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524"
  },
  "r169": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524"
  },
  "r17": {
   "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"
  },
  "r170": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524"
  },
  "r171": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524"
  },
  "r172": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5258-111524"
  },
  "r173": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "29",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953659-111524"
  },
  "r174": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5066-111524"
  },
  "r175": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "33",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953676-111524"
  },
  "r176": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "34",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953682-111524"
  },
  "r177": {
   "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"
  },
  "r178": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5086-111524"
  },
  "r179": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5111-111524"
  },
  "r18": {
   "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"
  },
  "r180": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953401-111524"
  },
  "r181": {
   "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"
  },
  "r182": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 6.L.1)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=122038336&loc=d3e74567-122707"
  },
  "r183": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/subtopic&trid=2196772"
  },
  "r184": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=6378536&loc=d3e10092-111533"
  },
  "r185": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(b)(1)(ii)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=121614798&loc=d3e15032-111544"
  },
  "r186": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554"
  },
  "r187": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10B",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=124260725&loc=SL120268667-111560"
  },
  "r188": {
   "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"
  },
  "r189": {
   "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"
  },
  "r19": {
   "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"
  },
  "r190": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27405-111563"
  },
  "r191": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL6283291-111563"
  },
  "r192": {
   "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"
  },
  "r193": {
   "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"
  },
  "r194": {
   "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"
  },
  "r195": {
   "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"
  },
  "r196": {
   "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"
  },
  "r197": {
   "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"
  },
  "r198": {
   "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"
  },
  "r199": {
   "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"
  },
  "r2": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=124098289&loc=d3e6676-107765"
  },
  "r20": {
   "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"
  },
  "r200": {
   "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"
  },
  "r201": {
   "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"
  },
  "r202": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r203": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(aa)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r204": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r205": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r206": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r207": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)(2)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r208": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)(3)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r209": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)(4)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r21": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19-26)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r210": {
   "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"
  },
  "r211": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL120269820-111563"
  },
  "r212": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL120269820-111563"
  },
  "r213": {
   "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"
  },
  "r214": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL120269825-111563"
  },
  "r215": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL120269825-111563"
  },
  "r216": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL120269825-111563"
  },
  "r217": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL120269825-111563"
  },
  "r218": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27290-111563"
  },
  "r219": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(2)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27290-111563"
  },
  "r22": {
   "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"
  },
  "r220": {
   "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"
  },
  "r221": {
   "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"
  },
  "r222": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27357-111563"
  },
  "r223": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27357-111563"
  },
  "r224": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "320",
   "URI": "http://asc.fasb.org/topic&trid=2196928"
  },
  "r225": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "321",
   "URI": "http://asc.fasb.org/extlink&oid=123583714&loc=SL75117360-209713"
  },
  "r226": {
   "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"
  },
  "r227": {
   "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"
  },
  "r228": {
   "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"
  },
  "r229": {
   "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"
  },
  "r23": {
   "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"
  },
  "r230": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "321",
   "URI": "http://asc.fasb.org/topic&trid=75115024"
  },
  "r231": {
   "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"
  },
  "r232": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "323",
   "URI": "http://asc.fasb.org/topic&trid=2196965"
  },
  "r233": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "325",
   "URI": "http://asc.fasb.org/topic&trid=2197064"
  },
  "r234": {
   "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"
  },
  "r235": {
   "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"
  },
  "r236": {
   "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"
  },
  "r237": {
   "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"
  },
  "r238": {
   "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"
  },
  "r239": {
   "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"
  },
  "r24": {
   "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"
  },
  "r240": {
   "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"
  },
  "r241": {
   "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"
  },
  "r242": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82921830-210448"
  },
  "r243": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82921833-210448"
  },
  "r244": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82921835-210448"
  },
  "r245": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82921835-210448"
  },
  "r246": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(d)(1)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82921835-210448"
  },
  "r247": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(d)(2)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82921835-210448"
  },
  "r248": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82921842-210448"
  },
  "r249": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "79",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448"
  },
  "r25": {
   "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"
  },
  "r250": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "80",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82922355-210448"
  },
  "r251": {
   "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"
  },
  "r252": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)(1)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455"
  },
  "r253": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)(2)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455"
  },
  "r254": {
   "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"
  },
  "r255": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455"
  },
  "r256": {
   "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"
  },
  "r257": {
   "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"
  },
  "r258": {
   "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"
  },
  "r259": {
   "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"
  },
  "r26": {
   "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"
  },
  "r260": {
   "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"
  },
  "r261": {
   "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"
  },
  "r262": {
   "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"
  },
  "r263": {
   "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"
  },
  "r264": {
   "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"
  },
  "r265": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "440",
   "URI": "http://asc.fasb.org/topic&trid=2144648"
  },
  "r266": {
   "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"
  },
  "r267": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "450",
   "URI": "http://asc.fasb.org/topic&trid=2127136"
  },
  "r268": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=124440162&loc=d3e12021-110248"
  },
  "r269": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(4)",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=124440162&loc=d3e12069-110248"
  },
  "r27": {
   "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"
  },
  "r270": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=123408193&loc=d3e12803-110250"
  },
  "r271": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "19",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=99376301&loc=d3e1398-112600"
  },
  "r272": {
   "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"
  },
  "r273": {
   "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"
  },
  "r274": {
   "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"
  },
  "r275": {
   "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"
  },
  "r276": {
   "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"
  },
  "r277": {
   "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"
  },
  "r278": {
   "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"
  },
  "r279": {
   "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"
  },
  "r28": {
   "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"
  },
  "r280": {
   "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"
  },
  "r281": {
   "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"
  },
  "r282": {
   "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"
  },
  "r283": {
   "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"
  },
  "r284": {
   "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"
  },
  "r285": {
   "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"
  },
  "r286": {
   "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"
  },
  "r287": {
   "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"
  },
  "r288": {
   "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"
  },
  "r289": {
   "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"
  },
  "r29": {
   "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"
  },
  "r290": {
   "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"
  },
  "r291": {
   "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"
  },
  "r292": {
   "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"
  },
  "r293": {
   "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"
  },
  "r294": {
   "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"
  },
  "r295": {
   "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"
  },
  "r296": {
   "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"
  },
  "r297": {
   "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"
  },
  "r298": {
   "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"
  },
  "r299": {
   "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"
  },
  "r3": {
   "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"
  },
  "r30": {
   "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"
  },
  "r300": {
   "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"
  },
  "r301": {
   "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"
  },
  "r302": {
   "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"
  },
  "r303": {
   "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"
  },
  "r304": {
   "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"
  },
  "r305": {
   "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"
  },
  "r306": {
   "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"
  },
  "r307": {
   "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"
  },
  "r308": {
   "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"
  },
  "r309": {
   "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"
  },
  "r31": {
   "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"
  },
  "r310": {
   "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"
  },
  "r311": {
   "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"
  },
  "r312": {
   "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"
  },
  "r313": {
   "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"
  },
  "r314": {
   "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"
  },
  "r315": {
   "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"
  },
  "r316": {
   "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"
  },
  "r317": {
   "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"
  },
  "r318": {
   "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"
  },
  "r319": {
   "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"
  },
  "r32": {
   "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"
  },
  "r320": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "30",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=6405686&loc=d3e22802-112653"
  },
  "r321": {
   "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"
  },
  "r322": {
   "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"
  },
  "r323": {
   "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"
  },
  "r324": {
   "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"
  },
  "r325": {
   "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"
  },
  "r326": {
   "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"
  },
  "r327": {
   "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"
  },
  "r328": {
   "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"
  },
  "r329": {
   "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"
  },
  "r33": {
   "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"
  },
  "r330": {
   "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"
  },
  "r331": {
   "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"
  },
  "r332": {
   "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"
  },
  "r333": {
   "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"
  },
  "r334": {
   "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"
  },
  "r335": {
   "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"
  },
  "r336": {
   "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"
  },
  "r337": {
   "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"
  },
  "r338": {
   "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"
  },
  "r339": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "606",
   "URI": "http://asc.fasb.org/topic&trid=49130388"
  },
  "r34": {
   "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"
  },
  "r340": {
   "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"
  },
  "r341": {
   "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"
  },
  "r342": {
   "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"
  },
  "r343": {
   "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"
  },
  "r344": {
   "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"
  },
  "r345": {
   "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"
  },
  "r346": {
   "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"
  },
  "r347": {
   "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"
  },
  "r348": {
   "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"
  },
  "r349": {
   "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"
  },
  "r35": {
   "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"
  },
  "r350": {
   "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"
  },
  "r351": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=123468992&loc=d3e4534-113899"
  },
  "r352": {
   "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"
  },
  "r353": {
   "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"
  },
  "r354": {
   "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"
  },
  "r355": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r356": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r357": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r358": {
   "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"
  },
  "r359": {
   "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"
  },
  "r36": {
   "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"
  },
  "r360": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r361": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r362": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r363": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(i)-(ii)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r364": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(iii)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r365": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(iv)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r366": {
   "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"
  },
  "r367": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(iv)(3)-(4)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r368": {
   "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"
  },
  "r369": {
   "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"
  },
  "r37": {
   "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"
  },
  "r370": {
   "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"
  },
  "r371": {
   "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"
  },
  "r372": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r373": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r374": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r375": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r376": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r377": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r378": {
   "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"
  },
  "r379": {
   "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"
  },
  "r38": {
   "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"
  },
  "r380": {
   "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"
  },
  "r381": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=SL79508275-113901"
  },
  "r382": {
   "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"
  },
  "r383": {
   "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"
  },
  "r384": {
   "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"
  },
  "r385": {
   "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"
  },
  "r386": {
   "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"
  },
  "r387": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=122142933&loc=d3e11149-113907"
  },
  "r388": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=122142933&loc=d3e11178-113907"
  },
  "r389": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "740",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120384911&loc=d3e23163-113944"
  },
  "r39": {
   "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"
  },
  "r390": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "718",
   "URI": "http://asc.fasb.org/topic&trid=2228938"
  },
  "r391": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "35",
   "Subparagraph": "(b)",
   "Topic": "720",
   "URI": "http://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848"
  },
  "r392": {
   "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"
  },
  "r393": {
   "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"
  },
  "r394": {
   "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"
  },
  "r395": {
   "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"
  },
  "r396": {
   "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"
  },
  "r397": {
   "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"
  },
  "r398": {
   "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"
  },
  "r399": {
   "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"
  },
  "r4": {
   "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"
  },
  "r40": {
   "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"
  },
  "r400": {
   "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"
  },
  "r401": {
   "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"
  },
  "r402": {
   "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"
  },
  "r403": {
   "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"
  },
  "r404": {
   "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"
  },
  "r405": {
   "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"
  },
  "r406": {
   "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"
  },
  "r407": {
   "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"
  },
  "r408": {
   "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"
  },
  "r409": {
   "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"
  },
  "r41": {
   "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"
  },
  "r410": {
   "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"
  },
  "r411": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "740",
   "URI": "http://asc.fasb.org/topic&trid=2144680"
  },
  "r412": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "15",
   "SubTopic": "10",
   "Subparagraph": "(f)(2)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116873149&loc=d3e923-111674"
  },
  "r413": {
   "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"
  },
  "r414": {
   "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"
  },
  "r415": {
   "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"
  },
  "r416": {
   "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"
  },
  "r417": {
   "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"
  },
  "r418": {
   "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"
  },
  "r419": {
   "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"
  },
  "r42": {
   "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"
  },
  "r420": {
   "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"
  },
  "r421": {
   "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"
  },
  "r422": {
   "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"
  },
  "r423": {
   "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"
  },
  "r424": {
   "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"
  },
  "r425": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4K",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(4)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5708775-113959"
  },
  "r426": {
   "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"
  },
  "r427": {
   "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"
  },
  "r428": {
   "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"
  },
  "r429": {
   "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"
  },
  "r43": {
   "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"
  },
  "r430": {
   "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"
  },
  "r431": {
   "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"
  },
  "r432": {
   "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"
  },
  "r433": {
   "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"
  },
  "r434": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bbb)(1)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r435": {
   "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"
  },
  "r436": {
   "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"
  },
  "r437": {
   "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"
  },
  "r438": {
   "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"
  },
  "r439": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=SL6742756-110258"
  },
  "r44": {
   "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"
  },
  "r440": {
   "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"
  },
  "r441": {
   "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"
  },
  "r442": {
   "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"
  },
  "r443": {
   "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"
  },
  "r444": {
   "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"
  },
  "r445": {
   "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"
  },
  "r446": {
   "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"
  },
  "r447": {
   "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"
  },
  "r448": {
   "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"
  },
  "r449": {
   "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"
  },
  "r45": {
   "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"
  },
  "r450": {
   "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"
  },
  "r451": {
   "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"
  },
  "r452": {
   "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"
  },
  "r453": {
   "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"
  },
  "r454": {
   "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"
  },
  "r455": {
   "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"
  },
  "r456": {
   "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"
  },
  "r457": {
   "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"
  },
  "r458": {
   "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"
  },
  "r459": {
   "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"
  },
  "r46": {
   "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"
  },
  "r460": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "840",
   "URI": "http://asc.fasb.org/extlink&oid=123386454&loc=d3e45280-112737"
  },
  "r461": {
   "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"
  },
  "r462": {
   "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"
  },
  "r463": {
   "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"
  },
  "r464": {
   "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"
  },
  "r465": {
   "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"
  },
  "r466": {
   "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"
  },
  "r467": {
   "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"
  },
  "r468": {
   "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"
  },
  "r469": {
   "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"
  },
  "r47": {
   "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"
  },
  "r470": {
   "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"
  },
  "r471": {
   "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"
  },
  "r472": {
   "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"
  },
  "r473": {
   "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"
  },
  "r474": {
   "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"
  },
  "r475": {
   "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"
  },
  "r476": {
   "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"
  },
  "r477": {
   "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"
  },
  "r478": {
   "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"
  },
  "r479": {
   "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"
  },
  "r48": {
   "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"
  },
  "r480": {
   "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"
  },
  "r481": {
   "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"
  },
  "r482": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(b)(1)(i)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729"
  },
  "r483": {
   "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"
  },
  "r484": {
   "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"
  },
  "r485": {
   "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"
  },
  "r486": {
   "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"
  },
  "r487": {
   "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"
  },
  "r488": {
   "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"
  },
  "r489": {
   "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"
  },
  "r49": {
   "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"
  },
  "r490": {
   "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"
  },
  "r491": {
   "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"
  },
  "r492": {
   "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"
  },
  "r493": {
   "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"
  },
  "r494": {
   "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"
  },
  "r495": {
   "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"
  },
  "r496": {
   "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"
  },
  "r497": {
   "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"
  },
  "r498": {
   "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"
  },
  "r499": {
   "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"
  },
  "r5": {
   "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"
  },
  "r50": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(10))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r500": {
   "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"
  },
  "r501": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "20",
   "Topic": "940",
   "URI": "http://asc.fasb.org/extlink&oid=123384075&loc=d3e41242-110953"
  },
  "r502": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "940",
   "URI": "http://asc.fasb.org/subtopic&trid=2176304"
  },
  "r503": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "210",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117340910&loc=d3e59706-112781"
  },
  "r504": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(1))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r505": {
   "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"
  },
  "r506": {
   "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"
  },
  "r507": {
   "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"
  },
  "r508": {
   "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"
  },
  "r509": {
   "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"
  },
  "r51": {
   "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"
  },
  "r510": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.10(4))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r511": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.12)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r512": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.13(3)(a))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r513": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.15(5))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r514": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.15)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r515": {
   "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"
  },
  "r516": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.2)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r517": {
   "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"
  },
  "r518": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(11))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r519": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(15))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r52": {
   "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"
  },
  "r520": {
   "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"
  },
  "r521": {
   "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"
  },
  "r522": {
   "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"
  },
  "r523": {
   "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"
  },
  "r524": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.1)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r525": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.1-5)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r526": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.10)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r527": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.11)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r528": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.12)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r529": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.13(b),(d))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r53": {
   "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"
  },
  "r530": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.13)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r531": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.14(b))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r532": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.14)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r533": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.2)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r534": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.4)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r535": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.6)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r536": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.8)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r537": {
   "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"
  },
  "r538": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "230",
   "Subparagraph": "(b)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123398031&loc=d3e60009-112784"
  },
  "r539": {
   "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"
  },
  "r54": {
   "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"
  },
  "r540": {
   "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"
  },
  "r541": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Subparagraph": "(b)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=d3e62586-112803"
  },
  "r542": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Subparagraph": "(c)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=d3e62586-112803"
  },
  "r543": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Subparagraph": "(d)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=d3e62586-112803"
  },
  "r544": {
   "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"
  },
  "r545": {
   "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"
  },
  "r546": {
   "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"
  },
  "r547": {
   "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"
  },
  "r548": {
   "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"
  },
  "r549": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=SL120269850-112803"
  },
  "r55": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(7)(c))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r550": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "942",
   "URI": "http://asc.fasb.org/subtopic&trid=2209399"
  },
  "r551": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "325",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599499&loc=d3e63345-112809"
  },
  "r552": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "360",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=124429447&loc=SL124453093-239630"
  },
  "r553": {
   "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"
  },
  "r554": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "405",
   "Subparagraph": "(c)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=116652737&loc=d3e64164-112818"
  },
  "r555": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "405",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=116652737&loc=d3e64164-112818"
  },
  "r556": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "470",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822"
  },
  "r557": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "470",
   "Subparagraph": "(d)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599511&loc=d3e64711-112823"
  },
  "r558": {
   "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"
  },
  "r559": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Subparagraph": "(a)(1)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826"
  },
  "r56": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(8))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r560": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Subparagraph": "(a)(2)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826"
  },
  "r561": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Subparagraph": "(b)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826"
  },
  "r562": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Subparagraph": "(c)(1)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826"
  },
  "r563": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Subparagraph": "(c)(2)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826"
  },
  "r564": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Subparagraph": "(e)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826"
  },
  "r565": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958569-112826"
  },
  "r566": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958570-112826"
  },
  "r567": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958573-112826"
  },
  "r568": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1F",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958575-112826"
  },
  "r569": {
   "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"
  },
  "r57": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(9)(a))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r570": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(10))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r571": {
   "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"
  },
  "r572": {
   "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"
  },
  "r573": {
   "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"
  },
  "r574": {
   "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"
  },
  "r575": {
   "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"
  },
  "r576": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(8))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r577": {
   "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"
  },
  "r578": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03.15(a))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r579": {
   "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"
  },
  "r58": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(b)(4))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r580": {
   "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"
  },
  "r581": {
   "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"
  },
  "r582": {
   "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"
  },
  "r583": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(8))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r584": {
   "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"
  },
  "r585": {
   "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"
  },
  "r586": {
   "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"
  },
  "r587": {
   "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"
  },
  "r588": {
   "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"
  },
  "r589": {
   "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"
  },
  "r59": {
   "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"
  },
  "r590": {
   "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"
  },
  "r591": {
   "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"
  },
  "r592": {
   "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"
  },
  "r593": {
   "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"
  },
  "r594": {
   "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"
  },
  "r595": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(e)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124508989&loc=d3e19393-158473"
  },
  "r596": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.6-03(f))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=123726495&loc=d3e600178-122990"
  },
  "r597": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=66023616&loc=SL35737432-115832"
  },
  "r598": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "220",
   "Subparagraph": "(k)",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=124433917&loc=SL114874205-224268"
  },
  "r599": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.6-07.2(a),(b),(c),(d))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=120401555&loc=SL114874292-224272"
  },
  "r6": {
   "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"
  },
  "r60": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.6)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r600": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "946",
   "URI": "http://asc.fasb.org/subtopic&trid=2324412"
  },
  "r601": {
   "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"
  },
  "r602": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "210",
   "Topic": "954",
   "URI": "http://asc.fasb.org/extlink&oid=120413173&loc=SL6242262-115580"
  },
  "r603": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "210",
   "Topic": "954",
   "URI": "http://asc.fasb.org/extlink&oid=120413209&loc=SL6242269-115581"
  },
  "r604": {
   "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"
  },
  "r605": {
   "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"
  },
  "r606": {
   "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"
  },
  "r607": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b"
  },
  "r608": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b-2"
  },
  "r609": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "d1-1"
  },
  "r61": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.7(c),9(a))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r610": {
   "Name": "Form 10-Q",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "308",
   "Subsection": "a"
  },
  "r611": {
   "Name": "Forms 10-K, 10-Q, 20-F",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "13",
   "Subsection": "a-1"
  },
  "r612": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1402"
  },
  "r613": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(1)"
  },
  "r614": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(2)"
  },
  "r615": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(3)"
  },
  "r616": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(c)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(2)(i)"
  },
  "r617": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(c)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(2)(ii)"
  },
  "r618": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(c)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(2)(iii)"
  },
  "r619": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1403"
  },
  "r62": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "220",
   "URI": "http://asc.fasb.org/topic&trid=2134417"
  },
  "r620": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1404"
  },
  "r621": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1404"
  },
  "r622": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1405",
   "Subparagraph": "(1)"
  },
  "r623": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1405",
   "Subparagraph": "(2)"
  },
  "r624": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1405",
   "Subparagraph": "(3)"
  },
  "r625": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1405",
   "Subparagraph": "(4)"
  },
  "r626": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(c)",
   "Publisher": "SEC",
   "Section": "1405"
  },
  "r627": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1406"
  },
  "r628": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1406",
   "Subparagraph": "(1)"
  },
  "r629": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1406",
   "Subparagraph": "(2)"
  },
  "r63": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3151-108585"
  },
  "r630": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1406",
   "Subparagraph": "(3)"
  },
  "r631": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1406",
   "Subparagraph": "(4)"
  },
  "r632": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1406",
   "Subparagraph": "(5)"
  },
  "r633": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(c)",
   "Publisher": "SEC",
   "Section": "1406"
  },
  "r634": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(d)",
   "Publisher": "SEC",
   "Section": "1406"
  },
  "r635": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(e)",
   "Publisher": "SEC",
   "Section": "1406"
  },
  "r636": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(f)",
   "Publisher": "SEC",
   "Section": "1406",
   "Subparagraph": "(1)"
  },
  "r637": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(f)",
   "Publisher": "SEC",
   "Section": "1406",
   "Subparagraph": "(2)"
  },
  "r638": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(f)",
   "Publisher": "SEC",
   "Section": "1406",
   "Subparagraph": "(2)(i)"
  },
  "r639": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(f)",
   "Publisher": "SEC",
   "Section": "1406",
   "Subparagraph": "(2)(i)(ii)"
  },
  "r64": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3179-108585"
  },
  "r640": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(f)",
   "Publisher": "SEC",
   "Section": "1406",
   "Subparagraph": "(2)(i)(iii)"
  },
  "r641": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(f)",
   "Publisher": "SEC",
   "Section": "1406",
   "Subparagraph": "(2)(i)(iv)"
  },
  "r642": {
   "Name": "Regulation S-T",
   "Number": "232",
   "Publisher": "SEC",
   "Section": "405"
  },
  "r643": {
   "Name": "Securities Act",
   "Number": "7A",
   "Publisher": "SEC",
   "Section": "B",
   "Subsection": "2"
  },
  "r644": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)(3)(iii)(03)",
   "Topic": "848"
  },
  "r65": {
   "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"
  },
  "r66": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3213-108585"
  },
  "r67": {
   "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"
  },
  "r68": {
   "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"
  },
  "r69": {
   "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"
  },
  "r7": {
   "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"
  },
  "r70": {
   "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"
  },
  "r71": {
   "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"
  },
  "r72": {
   "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"
  },
  "r73": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "19",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3444-108585"
  },
  "r74": {
   "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"
  },
  "r75": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21C",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=SL94080552-108585"
  },
  "r76": {
   "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"
  },
  "r77": {
   "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"
  },
  "r78": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3536-108585"
  },
  "r79": {
   "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"
  },
  "r8": {
   "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"
  },
  "r80": {
   "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"
  },
  "r81": {
   "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"
  },
  "r82": {
   "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"
  },
  "r83": {
   "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"
  },
  "r84": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3095-108585"
  },
  "r85": {
   "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"
  },
  "r86": {
   "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"
  },
  "r87": {
   "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"
  },
  "r88": {
   "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"
  },
  "r89": {
   "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"
  },
  "r9": {
   "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"
  },
  "r90": {
   "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"
  },
  "r91": {
   "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"
  },
  "r92": {
   "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"
  },
  "r93": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(m)(1)(ii)(A))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r94": {
   "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"
  },
  "r95": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "235",
   "URI": "http://asc.fasb.org/topic&trid=2122369"
  },
  "r96": {
   "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"
  },
  "r97": {
   "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"
  },
  "r98": {
   "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"
  },
  "r99": {
   "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"
  }
 },
 "version": "2.1"
}
