{
 "instance": {
  "jhg-20200630x10q.htm": {
   "axisCustom": 1,
   "axisStandard": 26,
   "contextCount": 338,
   "dts": {
    "calculationLink": {
     "local": [
      "jhg-20200630_cal.xml"
     ]
    },
    "definitionLink": {
     "local": [
      "jhg-20200630_def.xml"
     ],
     "remote": [
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-eedm-def-2019-01-31.xml",
      "http://xbrl.fasb.org/srt/2019/elts/srt-eedm1-def-2019-01-31.xml"
     ]
    },
    "inline": {
     "local": [
      "jhg-20200630x10q.htm"
     ]
    },
    "labelLink": {
     "local": [
      "jhg-20200630_lab.xml"
     ],
     "remote": [
      "https://xbrl.sec.gov/dei/2019/dei-doc-2019-01-31.xml",
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-doc-2019-01-31.xml"
     ]
    },
    "presentationLink": {
     "local": [
      "jhg-20200630_pre.xml"
     ]
    },
    "referenceLink": {
     "remote": [
      "https://xbrl.sec.gov/dei/2019/dei-ref-2019-01-31.xml",
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-ref-2019-01-31.xml"
     ]
    },
    "schema": {
     "local": [
      "jhg-20200630.xsd"
     ],
     "remote": [
      "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",
      "https://xbrl.sec.gov/dei/2019/dei-2019-01-31.xsd",
      "http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd",
      "http://www.xbrl.org/2005/xbrldt-2005.xsd",
      "http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd",
      "http://www.xbrl.org/dtr/type/numeric-2009-12-16.xsd",
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd",
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-roles-2019-01-31.xsd",
      "http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd",
      "http://www.xbrl.org/2006/ref-2006-02-27.xsd",
      "http://xbrl.fasb.org/srt/2019/elts/srt-types-2019-01-31.xsd",
      "http://xbrl.fasb.org/srt/2019/elts/srt-roles-2019-01-31.xsd",
      "https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd",
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-types-2019-01-31.xsd",
      "http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd",
      "http://www.xbrl.org/lrr/role/deprecated-2009-12-16.xsd",
      "http://www.xbrl.org/lrr/role/reference-2009-12-16.xsd",
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-parts-codification-2019-01-31.xsd"
     ]
    }
   },
   "elementCount": 529,
   "entityCount": 1,
   "hidden": {
    "http://fasb.org/us-gaap/2019-01-31": 7,
    "http://xbrl.sec.gov/dei/2019-01-31": 5,
    "total": 12
   },
   "keyCustom": 72,
   "keyStandard": 285,
   "memberCustom": 29,
   "memberStandard": 50,
   "nsprefix": "jhg",
   "nsuri": "http://www.janus.com/20200630",
   "report": {
    "R1": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "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.janus.com/role/DocumentDocumentAndEntityInformation",
     "shortName": "Document and Entity Information",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "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": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "jhg:VariableInterestEntitiesVotingRightsEntitiesConsolidationDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10301 - Disclosure - Consolidation",
     "role": "http://www.janus.com/role/DisclosureConsolidation",
     "shortName": "Consolidation",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "jhg:VariableInterestEntitiesVotingRightsEntitiesConsolidationDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R11": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "jhg:MarketableSecuritiesAndDerivativesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10401 - Disclosure - Investment Securities",
     "role": "http://www.janus.com/role/DisclosureInvestmentSecurities",
     "shortName": "Investment Securities",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "jhg:MarketableSecuritiesAndDerivativesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R12": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10501 - Disclosure - Fair Value Measurements",
     "role": "http://www.janus.com/role/DisclosureFairValueMeasurements",
     "shortName": "Fair Value Measurements",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R13": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:GoodwillAndIntangibleAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10601 - Disclosure - Goodwill and Intangible Assets",
     "role": "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssets",
     "shortName": "Goodwill and Intangible Assets",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:GoodwillAndIntangibleAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R14": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DebtDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10701 - Disclosure - Debt",
     "role": "http://www.janus.com/role/DisclosureDebt",
     "shortName": "Debt",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DebtDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R15": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeTaxDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10801 - Disclosure - Income Taxes",
     "role": "http://www.janus.com/role/DisclosureIncomeTaxes",
     "shortName": "Income Taxes",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "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": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:MinorityInterestDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10901 - Disclosure - Noncontrolling Interests",
     "role": "http://www.janus.com/role/DisclosureNoncontrollingInterests",
     "shortName": "Noncontrolling Interests",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:MinorityInterestDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R17": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "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 - Long-Term Incentive Compensation",
     "role": "http://www.janus.com/role/DisclosureLongTermIncentiveCompensation",
     "shortName": "Long-Term Incentive Compensation",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R18": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PensionAndOtherPostretirementBenefitsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11101 - Disclosure - Retirement Benefit Plans",
     "role": "http://www.janus.com/role/DisclosureRetirementBenefitPlans",
     "shortName": "Retirement Benefit Plans",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PensionAndOtherPostretirementBenefitsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R19": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ComprehensiveIncomeNoteTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11201 - Disclosure - Accumulated Other Comprehensive Loss",
     "role": "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLoss",
     "shortName": "Accumulated Other Comprehensive Loss",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ComprehensiveIncomeNoteTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R2": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_UFZv2hitQUyUOChbKutEPg",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "jhg:FeesAndOtherReceivablesCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00100 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS",
     "role": "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets",
     "shortName": "CONDENSED CONSOLIDATED BALANCE SHEETS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_UFZv2hitQUyUOChbKutEPg",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "jhg:FeesAndOtherReceivablesCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R20": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "jhg:EarningsAndDividendsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11301 - Disclosure - Earnings (Loss) and Dividends Per Share",
     "role": "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShare",
     "shortName": "Earnings (Loss) and Dividends Per Share",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "jhg:EarningsAndDividendsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R21": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11401 - Disclosure - Commitments and Contingencies",
     "role": "http://www.janus.com/role/DisclosureCommitmentsAndContingencies",
     "shortName": "Commitments and Contingencies",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R22": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfAccountingPolicyPolicyTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "20102 - Disclosure - Basis of Presentation and Significant Accounting Policies (Policies)",
     "role": "http://www.janus.com/role/DisclosureBasisOfPresentationAndSignificantAccountingPoliciesPolicies",
     "shortName": "Basis of Presentation and Significant Accounting Policies (Policies)",
     "subGroupType": "policies",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfAccountingPolicyPolicyTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R23": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30203 - Disclosure - Dispositions (Tables)",
     "role": "http://www.janus.com/role/DisclosureDispositionsTables",
     "shortName": "Dispositions (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R24": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "jhg:ConsolidatedVotingRightEntitiesVreTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30303 - Disclosure - Consolidation (Tables)",
     "role": "http://www.janus.com/role/DisclosureConsolidationTables",
     "shortName": "Consolidation (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "jhg:ConsolidatedVotingRightEntitiesVreTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R25": {
     "firstAnchor": {
      "ancestors": [
       "jhg:MarketableSecuritiesAndDerivativesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30403 - Disclosure - Investment Securities (Tables)",
     "role": "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables",
     "shortName": "Investment Securities (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "jhg:MarketableSecuritiesAndDerivativesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R26": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:FairValueDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30503 - Disclosure - Fair Value Measurements (Tables)",
     "role": "http://www.janus.com/role/DisclosureFairValueMeasurementsTables",
     "shortName": "Fair Value Measurements (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:FairValueDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R27": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:GoodwillAndIntangibleAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30603 - Disclosure - Goodwill and Intangible Assets (Tables)",
     "role": "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsTables",
     "shortName": "Goodwill and Intangible Assets (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:GoodwillAndIntangibleAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R28": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:DebtDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfDebtInstrumentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30703 - Disclosure - Debt (Tables)",
     "role": "http://www.janus.com/role/DisclosureDebtTables",
     "shortName": "Debt (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:DebtDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfDebtInstrumentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R29": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:IncomeTaxDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "jhg:ScheduleOfEffectiveIncomeTaxRatesTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30803 - Disclosure - Income Taxes (Tables)",
     "role": "http://www.janus.com/role/DisclosureIncomeTaxesTables",
     "shortName": "Income Taxes (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:IncomeTaxDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "jhg:ScheduleOfEffectiveIncomeTaxRatesTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R3": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_UFZv2hitQUyUOChbKutEPg",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:CommonStockParOrStatedValuePerShare",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Divide_USD_shares_N_Z68u4RSkmd7HtDyqw0SA",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00105 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)",
     "role": "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical",
     "shortName": "CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_UFZv2hitQUyUOChbKutEPg",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:CommonStockParOrStatedValuePerShare",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Divide_USD_shares_N_Z68u4RSkmd7HtDyqw0SA",
      "xsiNil": "false"
     }
    },
    "R30": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:MinorityInterestDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RedeemableNoncontrollingInterestTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30903 - Disclosure - Noncontrolling Interests (Tables)",
     "role": "http://www.janus.com/role/DisclosureNoncontrollingInterestsTables",
     "shortName": "Noncontrolling Interests (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:MinorityInterestDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RedeemableNoncontrollingInterestTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R31": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:PensionAndOtherPostretirementBenefitsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfNetBenefitCostsTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31103 - Disclosure - Retirement Benefit Plans (Tables)",
     "role": "http://www.janus.com/role/DisclosureRetirementBenefitPlansTables",
     "shortName": "Retirement Benefit Plans (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:PensionAndOtherPostretirementBenefitsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfNetBenefitCostsTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R32": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31203 - Disclosure - Accumulated Other Comprehensive Loss (Tables)",
     "role": "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossTables",
     "shortName": "Accumulated Other Comprehensive Loss (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R33": {
     "firstAnchor": {
      "ancestors": [
       "jhg:EarningsAndDividendsPerShareTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31303 - Disclosure - Earnings (Loss) and Dividends Per Share (Tables)",
     "role": "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareTables",
     "shortName": "Earnings (Loss) and Dividends Per Share (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "jhg:EarningsAndDividendsPerShareTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R34": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:NewAccountingPronouncementsPolicyPolicyTextBlock",
       "us-gaap:BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_us-gaap_AccountingStandardsUpdate201815Member_0xCk45bAAUyzTrnUL5Y00Q",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:CapitalizedComputerSoftwareAdditions",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40101 - Disclosure - Basis of Presentation and Significant Accounting Policies (Details)",
     "role": "http://www.janus.com/role/DisclosureBasisOfPresentationAndSignificantAccountingPoliciesDetails",
     "shortName": "Basis of Presentation and Significant Accounting Policies (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:NewAccountingPronouncementsPolicyPolicyTextBlock",
       "us-gaap:BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_us-gaap_AccountingStandardsUpdate201815Member_0xCk45bAAUyzTrnUL5Y00Q",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:CapitalizedComputerSoftwareAdditions",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R35": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:DisposalGroupNotDiscontinuedOperationGainLossOnDisposal",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40201 - Disclosure - Dispositions (Details)",
     "role": "http://www.janus.com/role/DisclosureDispositionsDetails",
     "shortName": "Dispositions (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "p",
       "us-gaap:DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_3_17_2020_srt_RangeAxis_srt_MaximumMember_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_jhg_GenevaCapitalManagementMember_hnliM0sbmkuBZnw-U-dOjw",
      "decimals": "-5",
      "lang": null,
      "name": "us-gaap:BusinessCombinationContingentConsiderationAsset",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R36": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:DisposalGroupNotDiscontinuedOperationGainLossOnDisposal",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40202 - Disclosure - Dispositions - Gain on Sale (Details)",
     "role": "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails",
     "shortName": "Dispositions - Gain on Sale (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_3_17_2020_srt_RestatementAxis_srt_ScenarioPreviouslyReportedMember_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_jhg_GenevaCapitalManagementMember_sWJwuofb5keEW-o0T26N8g",
      "decimals": "-5",
      "lang": null,
      "name": "us-gaap:DisposalGroupIncludingDiscontinuedOperationConsideration",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R37": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "jhg:VariableInterestEntitiesVotingRightsEntitiesConsolidationDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_us-gaap_VariableInterestEntityNotPrimaryBeneficiaryAggregatedDisclosureMember_NfRO3kVNd0KJwWrDpg-pSQ",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "jhg:MarketableSecuritiesAndDerivativeInstrumentsCurrent",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40301 - Disclosure - Consolidation - VIEs (Details)",
     "role": "http://www.janus.com/role/DisclosureConsolidationViesDetails",
     "shortName": "Consolidation - VIEs (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R38": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_UFZv2hitQUyUOChbKutEPg",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:OtherAssetsCurrent",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40302 - Disclosure - Consolidation - VREs (Details)",
     "role": "http://www.janus.com/role/DisclosureConsolidationVresDetails",
     "shortName": "Consolidation - VREs (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "jhg:ConsolidatedVotingRightEntitiesVreTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_jhg_VariableRightsEntityPrimaryBeneficiaryAggregatedDisclosureMember_XApxn7AZcUqKhZXH0IAACQ",
      "decimals": "-5",
      "lang": null,
      "name": "jhg:MarketableSecuritiesAndDerivativeInstrumentsCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R39": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:InvestmentTableTextBlock",
       "jhg:MarketableSecuritiesAndDerivativesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_UFZv2hitQUyUOChbKutEPg",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:InvestmentOwnedAtFairValue",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40401 - Disclosure - Investment Securities - General Disclosure (Details)",
     "role": "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
     "shortName": "Investment Securities - General Disclosure (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:InvestmentTableTextBlock",
       "jhg:MarketableSecuritiesAndDerivativesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_12_31_2019_kShfiaeOqUe1R1gRwnlL2g",
      "decimals": "-5",
      "lang": null,
      "name": "us-gaap:InvestmentOwnedAtFairValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R4": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_TzD2ECflJUe7LpEIdwpU1g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00200 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)",
     "role": "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss",
     "shortName": "CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_TzD2ECflJUe7LpEIdwpU1g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R40": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_UFZv2hitQUyUOChbKutEPg",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:DerivativeAssets",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40402 - Disclosure - Investment Securities - Offsetting Derivatives (Details)",
     "role": "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails",
     "shortName": "Investment Securities - Offsetting Derivatives (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:GainLossOnInvestmentsTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_us-gaap_InvestmentSecondaryCategorizationAxis_jhg_SeededInvestmentProductsAndDerivativesMember_yhqEVhBxg0GfZVS9_tDsAw",
      "decimals": "-5",
      "lang": null,
      "name": "us-gaap:GainLossOnInvestments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R41": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_UFZv2hitQUyUOChbKutEPg",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:DerivativeAssets",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40501 - Disclosure - Fair Value Measurements - Level of Fair Value (Details)",
     "role": "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
     "shortName": "Fair Value Measurements - Level of Fair Value (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock",
       "us-gaap:FairValueDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_us-gaap_FairValueByMeasurementFrequencyAxis_us-gaap_FairValueMeasurementsRecurringMember_Xg1M0T-oRU-YCxw3EaRjWQ",
      "decimals": "-5",
      "lang": null,
      "name": "us-gaap:CashAndCashEquivalentsFairValueDisclosure",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R42": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_us-gaap_FairValueByAssetClassAxis_us-gaap_SecuritiesAssetsMember_us-gaap_FairValueByFairValueHierarchyLevelAxis_us-gaap_FairValueInputsLevel3Member_us-gaap_FairValueByMeasurementFrequencyAxis_us-gaap_FairValueMeasurementsRecurringMember_us-gaap_MeasurementInputTypeAxis_us-gaap_MeasurementInputDiscountRateMember_us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_us-gaap_VariableInterestEntityPrimaryBeneficiaryAggregatedDisclosureMember_UlaevYBA80yoS1Mw5X5hPw",
      "decimals": "0",
      "first": true,
      "lang": null,
      "name": "us-gaap:AlternativeInvestmentMeasurementInput",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_beAkFWyNiEmjWzWnVDwIcg",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40502 - Disclosure - Fair Value Measurements - Valuation techniques and significant unobservable inputs (Details)",
     "role": "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails",
     "shortName": "Fair Value Measurements - Valuation techniques and significant unobservable inputs (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_us-gaap_FairValueByAssetClassAxis_us-gaap_SecuritiesAssetsMember_us-gaap_FairValueByFairValueHierarchyLevelAxis_us-gaap_FairValueInputsLevel3Member_us-gaap_FairValueByMeasurementFrequencyAxis_us-gaap_FairValueMeasurementsRecurringMember_us-gaap_MeasurementInputTypeAxis_us-gaap_MeasurementInputDiscountRateMember_us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_us-gaap_VariableInterestEntityPrimaryBeneficiaryAggregatedDisclosureMember_UlaevYBA80yoS1Mw5X5hPw",
      "decimals": "0",
      "first": true,
      "lang": null,
      "name": "us-gaap:AlternativeInvestmentMeasurementInput",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_beAkFWyNiEmjWzWnVDwIcg",
      "xsiNil": "false"
     }
    },
    "R43": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_3_31_2020_us-gaap_BusinessAcquisitionAxis_jhg_KapstreamCapitalPtyLimitedMember_RiesgzN_7E67Otwi_gsR6Q",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:BusinessCombinationContingentConsiderationLiability",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40503 - Disclosure - Fair Value Measurements - Contingent Consideration (Details)",
     "role": "http://www.janus.com/role/DisclosureFairValueMeasurementsContingentConsiderationDetails",
     "shortName": "Fair Value Measurements - Contingent Consideration (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R44": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:DisposalGroupNotDiscontinuedOperationGainLossOnDisposal",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40504 - Disclosure - Fair Value Measurements - Disposal of Geneva (Details)",
     "role": "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
     "shortName": "Fair Value Measurements - Disposal of Geneva (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_jhg_GenevaCapitalManagementMember_IQwhnjo-Rkuw5FfBWNS4OA",
      "decimals": "-5",
      "lang": null,
      "name": "jhg:ProceedsFromSaleOfBusinessContingentConsideration",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R45": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40505 - Disclosure - Fair Value Measurements - Acquisition of Kapstream (Details)",
     "role": "http://www.janus.com/role/DisclosureFairValueMeasurementsAcquisitionOfKapstreamDetails",
     "shortName": "Fair Value Measurements - Acquisition of Kapstream (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_1_31_2017_us-gaap_BusinessAcquisitionAxis_jhg_KapstreamCapitalPtyLimitedMember_vx_XYSeV40SfvM4KybjCmA",
      "decimals": "2",
      "lang": null,
      "name": "us-gaap:BusinessAcquisitionPercentageOfVotingInterestsAcquired",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_beAkFWyNiEmjWzWnVDwIcg",
      "xsiNil": "false"
     }
    },
    "R46": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "jhg:BusinessCombinationContingentConsiderationForecastingRevenuesTerm",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40506 - Disclosure - Fair Value Measurements - Disposal of Volantis (Details)",
     "role": "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails",
     "shortName": "Fair Value Measurements - Disposal of Volantis (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "jhg:BusinessCombinationContingentConsiderationForecastingRevenuesTerm",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R47": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "jhg:ScheduleOfDerivativeInstrumentsDenominatedInForeignCurrencyGainsLossesInStatementOfFinancialPerformanceTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_TzD2ECflJUe7LpEIdwpU1g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:ForeignCurrencyTransactionGainLossRealized",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40507 - Disclosure - Fair Value Measurements - Level 3 Rollforward (Details)",
     "role": "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails",
     "shortName": "Fair Value Measurements - Level 3 Rollforward (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "jhg:FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCollectiveItemsTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_3_31_2020_JOjDpp66N0CBuAXsClYL2g",
      "decimals": "-5",
      "lang": null,
      "name": "us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R48": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock",
       "us-gaap:GoodwillAndIntangibleAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_12_31_2018_G_5280K680S56ji8SCBXTQ",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40601 - Disclosure - Goodwill and Intangible Assets (Details)",
     "role": "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails",
     "shortName": "Goodwill and Intangible Assets (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock",
       "us-gaap:GoodwillAndIntangibleAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_12_31_2018_G_5280K680S56ji8SCBXTQ",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R49": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfDebtInstrumentsTextBlock",
       "us-gaap:DebtDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_us-gaap_DebtInstrumentAxis_jhg_SeniorNotes4.875PercentDue2025Member_7JWB17rzs06N6cpSQEdhfQ",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:DebtInstrumentInterestRateStatedPercentage",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_beAkFWyNiEmjWzWnVDwIcg",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40701 - Disclosure - Debt (Details)",
     "role": "http://www.janus.com/role/DisclosureDebtDetails",
     "shortName": "Debt (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfDebtInstrumentsTextBlock",
       "us-gaap:DebtDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_us-gaap_DebtInstrumentAxis_jhg_SeniorNotes4.875PercentDue2025Member_7JWB17rzs06N6cpSQEdhfQ",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:DebtInstrumentInterestRateStatedPercentage",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_beAkFWyNiEmjWzWnVDwIcg",
      "xsiNil": "false"
     }
    },
    "R5": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:ProfitLoss",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00300 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS",
     "role": "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows",
     "shortName": "CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": "-5",
      "lang": null,
      "name": "us-gaap:DepreciationDepletionAndAmortization",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R50": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "jhg:ScheduleOfEffectiveIncomeTaxRatesTableTextBlock",
       "us-gaap:IncomeTaxDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_TzD2ECflJUe7LpEIdwpU1g",
      "decimals": "3",
      "first": true,
      "lang": null,
      "name": "us-gaap:EffectiveIncomeTaxRateContinuingOperations",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_beAkFWyNiEmjWzWnVDwIcg",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40801 - Disclosure - Income Taxes (Details)",
     "role": "http://www.janus.com/role/DisclosureIncomeTaxesDetails",
     "shortName": "Income Taxes (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "jhg:ScheduleOfEffectiveIncomeTaxRatesTableTextBlock",
       "us-gaap:IncomeTaxDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_TzD2ECflJUe7LpEIdwpU1g",
      "decimals": "3",
      "first": true,
      "lang": null,
      "name": "us-gaap:EffectiveIncomeTaxRateContinuingOperations",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_beAkFWyNiEmjWzWnVDwIcg",
      "xsiNil": "false"
     }
    },
    "R51": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_UFZv2hitQUyUOChbKutEPg",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:RedeemableNoncontrollingInterestEquityFairValue",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40901 - Disclosure - Noncontrolling Interests - Redeemable (Details)",
     "role": "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails",
     "shortName": "Noncontrolling Interests - Redeemable (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "jhg:NoncontrollingInterestIncreaseDecreaseTableTextBlock",
       "us-gaap:MinorityInterestDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_us-gaap_InvestmentSecondaryCategorizationAxis_jhg_SeededInvestmentProductsMember_8DnHm51T_Eu-A9J_GgxP4w",
      "decimals": "-5",
      "lang": null,
      "name": "jhg:MinorityInterestPeriodIncreaseDecreaseMarketValueOfSeededInvestmentProducts",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R52": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "jhg:ScheduleOfNonredeemableNoncontrollingInterestTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_UFZv2hitQUyUOChbKutEPg",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:MinorityInterest",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40902 - Disclosure - Noncontrolling Interests - Nonredeemable (Details)",
     "role": "http://www.janus.com/role/DisclosureNoncontrollingInterestsNonredeemableDetails",
     "shortName": "Noncontrolling Interests - Nonredeemable (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "jhg:ScheduleOfNonredeemableNoncontrollingInterestTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_6_30_2020_UFZv2hitQUyUOChbKutEPg",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:MinorityInterest",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R53": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_TzD2ECflJUe7LpEIdwpU1g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "jhg:ShareBasedCompensationArrangementByShareBasedPaymentAwardTotal",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41001 - Disclosure - Long-Term Incentive and Employee Compensation (Details)",
     "role": "http://www.janus.com/role/DisclosureLongTermIncentiveAndEmployeeCompensationDetails",
     "shortName": "Long-Term Incentive and Employee Compensation (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_TzD2ECflJUe7LpEIdwpU1g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "jhg:ShareBasedCompensationArrangementByShareBasedPaymentAwardTotal",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R54": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfNetBenefitCostsTableTextBlock",
       "us-gaap:PensionAndOtherPostretirementBenefitsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_TzD2ECflJUe7LpEIdwpU1g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:DefinedBenefitPlanServiceCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41101 - Disclosure - Retirement benefit plans - Actuarial gains(losses), benefit cost, cash flows (Details)",
     "role": "http://www.janus.com/role/DisclosureRetirementBenefitPlansActuarialGainsLossesBenefitCostCashFlowsDetails",
     "shortName": "Retirement benefit plans - Actuarial gains(losses), benefit cost, cash flows (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfNetBenefitCostsTableTextBlock",
       "us-gaap:PensionAndOtherPostretirementBenefitsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_TzD2ECflJUe7LpEIdwpU1g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:DefinedBenefitPlanServiceCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R55": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_12_31_2019_kShfiaeOqUe1R1gRwnlL2g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:StockholdersEquity",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41201 - Disclosure - Accumulated Other Comprehensive Loss (Details)",
     "role": "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails",
     "shortName": "Accumulated Other Comprehensive Loss (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_3_31_2020_us-gaap_StatementEquityComponentsAxis_us-gaap_AccumulatedOtherComprehensiveIncomeMember_IxwabN59nkO3f5EGth27MQ",
      "decimals": "-5",
      "lang": null,
      "name": "us-gaap:StockholdersEquity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R56": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_TzD2ECflJUe7LpEIdwpU1g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41202 - Disclosure - Accumulated Other Comprehensive Loss - OCI (Details)",
     "role": "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossOciDetails",
     "shortName": "Accumulated Other Comprehensive Loss - OCI (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_TzD2ECflJUe7LpEIdwpU1g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R57": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_TzD2ECflJUe7LpEIdwpU1g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:UndistributedEarnings",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41301 - Disclosure - Earnings (Loss) and Dividends Per Share (Details)",
     "role": "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails",
     "shortName": "Earnings (Loss) and Dividends Per Share (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
       "jhg:EarningsAndDividendsPerShareTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_TzD2ECflJUe7LpEIdwpU1g",
      "decimals": "-5",
      "lang": null,
      "name": "us-gaap:UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R6": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_12_31_2018_us-gaap_StatementEquityComponentsAxis_us-gaap_CommonStockMember_Z-sOlY1gN0-USFZYXDeI1g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00400 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY",
     "role": "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity",
     "shortName": "CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "As_Of_12_31_2018_us-gaap_StatementEquityComponentsAxis_us-gaap_CommonStockMember_Z-sOlY1gN0-USFZYXDeI1g",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_saf-iSHPr0SNV-msbTQyfQ",
      "xsiNil": "false"
     }
    },
    "R7": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_4_1_2020_To_6_30_2020_TzD2ECflJUe7LpEIdwpU1g",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:CommonStockDividendsPerShareCashPaid",
      "reportCount": 1,
      "unitRef": "Unit_Divide_USD_shares_N_Z68u4RSkmd7HtDyqw0SA",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00405 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical)",
     "role": "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquityParenthetical",
     "shortName": "CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": null
    },
    "R8": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10101 - Disclosure - Basis of Presentation and Significant Accounting Policies",
     "role": "http://www.janus.com/role/DisclosureBasisOfPresentationAndSignificantAccountingPolicies",
     "shortName": "Basis of Presentation and Significant Accounting Policies",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R9": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10201 - Disclosure - Dispositions",
     "role": "http://www.janus.com/role/DisclosureDispositions",
     "shortName": "Dispositions",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "jhg-20200630x10q.htm",
      "contextRef": "Duration_1_1_2020_To_6_30_2020_2dtnkNg1WEil39y929Jjgg",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    }
   },
   "segmentCount": 80,
   "tag": {
    "country_GB": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "G [B]",
        "terseLabel": "UK"
       }
      }
     },
     "localname": "GB",
     "nsuri": "http://xbrl.sec.gov/country/2017-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "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/2019-01-31",
     "presentation": [
      "http://www.janus.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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_CountryRegion": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Region code of country",
        "label": "Country Region"
       }
      }
     },
     "localname": "CountryRegion",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_CoverAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Cover page.",
        "label": "Document and Entity Information"
       }
      }
     },
     "localname": "CoverAbstract",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "fiscalPeriodItemType"
    },
    "dei_DocumentFiscalYearFocus": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This is focus fiscal year of the document report in CCYY 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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "gYearItemType"
    },
    "dei_DocumentPeriodEndDate": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented.  If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD.",
        "label": "Document Period End Date"
       }
      }
     },
     "localname": "DocumentPeriodEndDate",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "dateItemType"
    },
    "dei_DocumentQuarterlyReport": {
     "auth_ref": [
      "r383"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_DocumentTransitionReport": {
     "auth_ref": [
      "r384"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.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/2019-01-31",
     "presentation": [
      "http://www.janus.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/2019-01-31",
     "presentation": [
      "http://www.janus.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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressCountry": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "ISO 3166-1 alpha-2 country code.",
        "label": "Entity Address, Country"
       }
      }
     },
     "localname": "EntityAddressCountry",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "countryCodeItemType"
    },
    "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityCentralIndexKey": {
     "auth_ref": [
      "r385"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.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",
        "terseLabel": "Entity Common Stock, Shares Outstanding"
       }
      }
     },
     "localname": "EntityCommonStockSharesOutstanding",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.janus.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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "All the names of the entities being reported upon in a document. Any legal structure used to conduct activities or to hold assets. Some examples of such structures are corporations, partnerships, limited liability companies, grantor trusts, and other trusts. This item does not include business and geographical segments which are included in the geographical or business segments domains.",
        "label": "Entity [Domain]",
        "terseLabel": "Entity [Domain]"
       }
      }
     },
     "localname": "EntityDomain",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "dei_EntityEmergingGrowthCompany": {
     "auth_ref": [
      "r385"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "fileNumberItemType"
    },
    "dei_EntityFilerCategory": {
     "auth_ref": [
      "r385"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "edgarStateCountryItemType"
    },
    "dei_EntityInteractiveDataCurrent": {
     "auth_ref": [
      "r386"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityRegistrantName": {
     "auth_ref": [
      "r385"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityShellCompany": {
     "auth_ref": [
      "r385"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntitySmallBusiness": {
     "auth_ref": [
      "r385"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntityTaxIdentificationNumber": {
     "auth_ref": [
      "r385"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "employerIdItemType"
    },
    "dei_LegalEntityAxis": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The set of legal entities associated with a report.",
        "label": "Legal Entity [Axis]"
       }
      }
     },
     "localname": "LegalEntityAxis",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_Security12bTitle": {
     "auth_ref": [
      "r381"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "securityTitleItemType"
    },
    "dei_SecurityExchangeName": {
     "auth_ref": [
      "r382"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "tradingSymbolItemType"
    },
    "jhg_AccumulatedAmortizationRelatedToForeignCurrencyTranslationGainLoss": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "It represents the amount of accumulated amortization related to foreign currency translation gain loss.",
        "label": "Accumulated Amortization Related to Foreign Currency Translation Gain Loss",
        "terseLabel": "Foreign currency translation"
       }
      }
     },
     "localname": "AccumulatedAmortizationRelatedToForeignCurrencyTranslationGainLoss",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_AmortizationOfShareBasedIncentiveRights": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the amortization of share-based incentive rights.",
        "label": "Amortization of Share Based Incentive Rights",
        "verboseLabel": "INTECH appreciation rights"
       }
      }
     },
     "localname": "AmortizationOfShareBasedIncentiveRights",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_AmountOfFairValueGreaterThanLessThanCarryingValue": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount that fair value is greater than or (less than) the carrying value of Goodwill and/or intangible assets.",
        "label": "Amount of Fair Value Greater Than Less Than Carrying Value",
        "terseLabel": "The amount of fair value greater than carrying value for goodwill"
       }
      }
     },
     "localname": "AmountOfFairValueGreaterThanLessThanCarryingValue",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_AmountOfPerformanceFeesGeneratedAsPartOfConsideration": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represent the amount of performance fees generated that would be a part of the sales consideration.",
        "label": "Amount Of Performance Fees Generated as Part of Consideration",
        "terseLabel": "Performance fee threshold"
       }
      }
     },
     "localname": "AmountOfPerformanceFeesGeneratedAsPartOfConsideration",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_BasisOfPresentationAndSignificantAccountingPoliciesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "No definition available.",
        "label": "Basis of Presentation and Significant Accounting Policies"
       }
      }
     },
     "localname": "BasisOfPresentationAndSignificantAccountingPoliciesAbstract",
     "nsuri": "http://www.janus.com/20200630",
     "xbrltype": "stringItemType"
    },
    "jhg_BusinessCombinationContingentConsiderationForecastingRevenuesTerm": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the business combination contingent consideration forecasting revenues term.",
        "label": "Business Combination Contingent Consideration Forecasting Revenues Term",
        "terseLabel": "Revenue forecasting period"
       }
      }
     },
     "localname": "BusinessCombinationContingentConsiderationForecastingRevenuesTerm",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "jhg_CashFlowsRelatedToInvestmentSecuritiesAndOtherAssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Cash Flows Related to Investment Securities and Other Assets [Abstract]",
        "terseLabel": "Cash flows related to investment securities"
       }
      }
     },
     "localname": "CashFlowsRelatedToInvestmentSecuritiesAndOtherAssetsAbstract",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "jhg_CashFlowsRelatedToInvestmentSecuritiesAndOtherAssetsTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of cash flows related to investment securities and other assets.",
        "label": "Cash Flows Related to Investment Securities and Other Assets [Table Text Block]",
        "terseLabel": "Cash flows related to investment securities"
       }
      }
     },
     "localname": "CashFlowsRelatedToInvestmentSecuritiesAndOtherAssetsTableTextBlock",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jhg_CertainFundMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents a certain fund related to Volantis UK Small Cap.",
        "label": "Certain Fund [Member]",
        "terseLabel": "Certain fund"
       }
      }
     },
     "localname": "CertainFundMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_ConsiderationForSaleBasedOnRevenueOfInvesteePercentage": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Consideration for the sale was based on percentage share of the management and performance fees generated by investee.",
        "label": "Consideration for Sale Based on Revenue of Investee, Percentage",
        "terseLabel": "Percentage of share for consideration of sale"
       }
      }
     },
     "localname": "ConsiderationForSaleBasedOnRevenueOfInvesteePercentage",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "jhg_ConsolidatedVotingRightEntitiesVreTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The table represents information on consolidated voting right entities (VREs).",
        "label": "Consolidated Voting Right Entities (VRE) [Table Text Block]",
        "verboseLabel": "Schedule of consolidated voting right entities (VREs)"
       }
      }
     },
     "localname": "ConsolidatedVotingRightEntitiesVreTableTextBlock",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jhg_ContingentConsiderationMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents member information pertaining to contingent consideration in a business combination transaction.",
        "label": "Contingent Consideration [Member]",
        "terseLabel": "Contingent consideration"
       }
      }
     },
     "localname": "ContingentConsiderationMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_ContractsForDifferencesMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents information on contracts for differences under derivative instruments.",
        "label": "Contracts For Differences [Member]",
        "terseLabel": "Contracts for differences"
       }
      }
     },
     "localname": "ContractsForDifferencesMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_DeferredBonusesHedgeLiabilityMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents information pertaining to Deferred bonuses hedge liability.",
        "label": "Deferred Bonuses Hedge Liability [Member]",
        "terseLabel": "Deferred bonuses"
       }
      }
     },
     "localname": "DeferredBonusesHedgeLiabilityMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_DeferredCompensationHedgeAssetMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the information pertaining to deferred compensation hedge asset.",
        "label": "Deferred Compensation Hedge Asset [Member]",
        "terseLabel": "Investments related to deferred compensation plans"
       }
      }
     },
     "localname": "DeferredCompensationHedgeAssetMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_DeferredEquityPlanMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This member stands for Deferred equity plan.",
        "label": "Deferred Equity Plan [Member]",
        "terseLabel": "Deferred Equity Plan"
       }
      }
     },
     "localname": "DeferredEquityPlanMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_DefinedBenefitPlanPeriodicBenefitCostCreditBeforeContributionToMoneyPurchaseSection": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/DisclosureRetirementBenefitPlansActuarialGainsLossesBenefitCostCashFlowsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of net periodic benefit cost (credit) for defined benefit plan before contribution to money purchase section.",
        "label": "Defined Benefit Plan, Periodic Benefit Cost (Credit), Before Contribution to Money Purchase Section",
        "negatedTotalLabel": "Net periodic benefit credit"
       }
      }
     },
     "localname": "DefinedBenefitPlanPeriodicBenefitCostCreditBeforeContributionToMoneyPurchaseSection",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureRetirementBenefitPlansActuarialGainsLossesBenefitCostCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_DepreciationDepletionAmortizationAndImpairment": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 6.0,
       "parentTag": "us-gaap_CostsAndExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets. It may also include impairment charges on tangible or intangible assets.",
        "label": "Depreciation, Depletion, Amortization and Impairment",
        "terseLabel": "Depreciation and amortization"
       }
      }
     },
     "localname": "DepreciationDepletionAmortizationAndImpairment",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_DerivativeInstrumentDenominatedInForeignCurrencyAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "No definition available.",
        "label": "Derivative Instrument Denominated in Foreign Currency [Abstract]",
        "terseLabel": "Net gains (losses) in net income related to:",
        "verboseLabel": "Derivative Instrument Denominated in Foreign Currency"
       }
      }
     },
     "localname": "DerivativeInstrumentDenominatedInForeignCurrencyAbstract",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "jhg_DerivativeInstrumentsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the information pertaining to derivative instruments.",
        "label": "Derivative Instruments [Member]",
        "terseLabel": "Derivative Instruments"
       }
      }
     },
     "localname": "DerivativeInstrumentsMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainsLossesNetDenominatedInForeignCurrency": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails": {
       "order": 2.0,
       "parentTag": "jhg_GainsLossesOnDerivativeInstrumentsHeldForTradingPurposesNetDenominatedInForeignCurrency",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the net gain (loss) from the increase (decrease) in fair value of derivative instrument denominated in a foreign currency not designated as hedging instrument.",
        "label": "Derivative Instruments Not Designated as Hedging Instruments Gains (Losses) Net Denominated in Foreign Currency",
        "terseLabel": "Foreign currency forward contracts"
       }
      }
     },
     "localname": "DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainsLossesNetDenominatedInForeignCurrency",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_EarningsAndDividendsPerShareTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for earnings per share as well as dividends per share.",
        "label": "Earnings and Dividends Per Share [Text Block]",
        "terseLabel": "Earnings (Loss) and Dividends Per Share"
       }
      }
     },
     "localname": "EarningsAndDividendsPerShareTextBlock",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShare"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jhg_EmployeeRelatedLiabilitiesNoncurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the non-current portion of the liabilities.",
        "label": "Employee Related Liabilities Noncurrent",
        "terseLabel": "Accrued compensation, benefits and staff costs"
       }
      }
     },
     "localname": "EmployeeRelatedLiabilitiesNoncurrent",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_FairValueAdjustmentsToRedeemableNoncontrollingInterests": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the amount of fair value adjustments to redeemable noncontrolling interests.",
        "label": "Fair Value Adjustments to Redeemable Noncontrolling Interests",
        "terseLabel": "Fair value adjustments to redeemable noncontrolling interests"
       }
      }
     },
     "localname": "FairValueAdjustmentsToRedeemableNoncontrollingInterests",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetAndLiabilityClassDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents classes of assets and liabilities measured and disclosed at fair value.",
        "label": "Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation By Asset And Liability Class [Domain]",
        "terseLabel": "Fair Value Assets and Liabilities, Measured on Recurring Basis, Unobservable Input Reconciliation, by Asset and Liability Class [Domain]"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetAndLiabilityClassDomain",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCollectiveItemsTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the fair value measurement for collective items of assets and liabilities using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period.",
        "label": "Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Collective Items [Table Text Block]",
        "terseLabel": "Schedule of changes in fair value of the recurring Level 3 fair value measurements for collective items"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCollectiveItemsTableTextBlock",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jhg_FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationIndividualItemsTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the fair value measurement for individual items of assets and liabilities using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period.",
        "label": "Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Individual Items [Table Text Block]",
        "terseLabel": "Schedule of changes in fair value of the recurring Level 3 fair value measurements for individual items"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationIndividualItemsTableTextBlock",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jhg_FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems": {
     "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 Basis, Unobservable Input Reconciliation [Line Items]",
        "terseLabel": "Changes in fair value of the recurring Level 3 fair value measurement"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "jhg_FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Fair Value, Assets and Liabilities, Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]",
        "terseLabel": "Changes in fair value"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationRollForward",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "jhg_FairValueByAssetAndLiabilityClassAxis": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fair value information by class of asset and liability.",
        "label": "Fair Value by Asset and Liability Class [Axis]"
       }
      }
     },
     "localname": "FairValueByAssetAndLiabilityClassAxis",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "jhg_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of gain (loss) recognized on the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings",
        "negatedLabel": "Movements recognized in net income"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncome": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of gain (loss) recognized in other comprehensive income (loss) for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income",
        "negatedLabel": "Movements recognized in other comprehensive income"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncome",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSellOff": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of sell off of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sell Off",
        "terseLabel": "Geneva sell off"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSellOff",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityAdjustments": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of adjustments of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Adjustments",
        "terseLabel": "Fair value adjustments"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityAdjustments",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityDistributionsToNonControllingInterestHolders": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of distributions to non controlling interest holders of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Distributions to Non controlling Interest Holders",
        "negatedLabel": "Distributions"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityDistributionsToNonControllingInterestHolders",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityUnrealizedLoss": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of unrealized losses of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Unrealized loss",
        "negatedLabel": "Unrealized gains (losses)"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityUnrealizedLoss",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_FairvalueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityAmortizationOfDeferredBonuses": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of amortization of deferred bonuses of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "FairValue, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Amortization of deferred bonuses",
        "terseLabel": "Amortization of deferred bonuses"
       }
      }
     },
     "localname": "FairvalueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityAmortizationOfDeferredBonuses",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_FairvalueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityVestingOfDeferredBonuses": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of vesting of defered bonuses of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "FairValue, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Vesting of Deferred Bonuses",
        "terseLabel": "Vesting of deferred bonuses"
       }
      }
     },
     "localname": "FairvalueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityVestingOfDeferredBonuses",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_FeesAndOtherReceivablesCurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "It represents the fees and other receivables due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer).",
        "label": "Fees and Other Receivables, Current",
        "terseLabel": "Fees and other receivables"
       }
      }
     },
     "localname": "FeesAndOtherReceivablesCurrent",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_GainLossOnInvestmentsNet": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 8.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of realized and unrealized gain (loss) on investment, net.",
        "label": "Gain (Loss) on Investments, Net",
        "negatedLabel": "Investment (gains) losses, net"
       }
      }
     },
     "localname": "GainLossOnInvestmentsNet",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_GainsLossesOnDerivativeInstrumentsHeldForTradingPurposesNetDenominatedInForeignCurrency": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the aggregate net gains and losses (whether realized or unrealized) on all derivative instruments denominated in a foreign currency held for trading purposes whether or not settled physically.",
        "label": "Gains (Losses) on Derivative Instruments Held for Trading Purposes Net Denominated in Foreign Currency",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "GainsLossesOnDerivativeInstrumentsHeldForTradingPurposesNetDenominatedInForeignCurrency",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_GenevaCapitalManagementMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents Geneva Capital Management.",
        "label": "Geneva Capital Management [Member]",
        "terseLabel": "Geneva"
       }
      }
     },
     "localname": "GenevaCapitalManagementMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsDetails",
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_IncreaseDecreaseInOEICAndUnitTrustReceivablesAndPayables": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 13.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (Decrease) in OEIC and unit trust receivables and payables.",
        "label": "Increase (Decrease) in O E I C and Unit Trust Receivables and Payables",
        "negatedLabel": "OEIC and unit trust receivables and payables"
       }
      }
     },
     "localname": "IncreaseDecreaseInOEICAndUnitTrustReceivablesAndPayables",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_IntangibleAssetsNetExcludingGoodwillRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Intangible Assets, Net Excluding Goodwill [Roll Forward]",
        "terseLabel": "Net intangible assets"
       }
      }
     },
     "localname": "IntangibleAssetsNetExcludingGoodwillRollForward",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "jhg_IntangibleAssetsTranslationAdjustments": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease) to intangible assets, excluding financial assets and goodwill, lacking physical substance for foreign currency translation adjustments.",
        "label": "Intangible Assets, Translation Adjustments",
        "terseLabel": "Foreign currency translation"
       }
      }
     },
     "localname": "IntangibleAssetsTranslationAdjustments",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_IntechFoundersMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents founding members of INTECH retaining a noncontrolling ownership interest.",
        "label": "Intech Founders [Member]",
        "terseLabel": "Intech Founders"
       }
      }
     },
     "localname": "IntechFoundersMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_IntechMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Entity owned or controlled by another entity.",
        "label": "Intech [Member]",
        "terseLabel": "Intech"
       }
      }
     },
     "localname": "IntechMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_InvestmentAdministrationExpense": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 3.0,
       "parentTag": "us-gaap_CostsAndExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "It represents the operating expenses relating to investment administration during the period.",
        "label": "Investment Administration Expense",
        "terseLabel": "Investment administration"
       }
      }
     },
     "localname": "InvestmentAdministrationExpense",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_InvestmentInSeededInvestmentProducts": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the seeding of various investment products.",
        "label": "Investment in Seeded Investment Products",
        "terseLabel": "Seeded investment products"
       }
      }
     },
     "localname": "InvestmentInSeededInvestmentProducts",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_InvestmentManagementAgreementsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents investment management agreements.",
        "label": "Investment Management Agreements [Member]",
        "terseLabel": "Investment management agreements"
       }
      }
     },
     "localname": "InvestmentManagementAgreementsMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_KapstreamCapitalPtyLimitedMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents information pertaining to Kapstream Capital Pty Limited.",
        "label": "Kapstream Capital Pty Limited [Member]",
        "terseLabel": "Kapstream"
       }
      }
     },
     "localname": "KapstreamCapitalPtyLimitedMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsAcquisitionOfKapstreamDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsContingentConsiderationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_LineOfCreditFacilityCovenantTermsFinancingLeverageRatioUpperRangeLimit": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Under the terms for borrowing under the credit facility, the financing leverage ratio cannot exceed this ratio.",
        "label": "Line of Credit Facility, Covenant Terms Financing Leverage Ratio, Upper Range Limit",
        "terseLabel": "Credit facility covenant terms, financing leverage ratio, maximum"
       }
      }
     },
     "localname": "LineOfCreditFacilityCovenantTermsFinancingLeverageRatioUpperRangeLimit",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "jhg_LongTailAlphaMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the information pertaining to Long Tail Alpha.",
        "label": "Long Tail Alpha [Member]",
        "terseLabel": "Long Tail Alpha"
       }
      }
     },
     "localname": "LongTailAlphaMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_LongTermDebtCurrentFairValue": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_LiabilitiesFairValueDisclosure",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The fair value of current portion long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.",
        "label": "Long Term Debt, Current Fair Value",
        "terseLabel": "Current portion of long-term debt"
       }
      }
     },
     "localname": "LongTermDebtCurrentFairValue",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_MarketableSecuritiesAndDerivativeInstrumentsCurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/DisclosureConsolidationVresDetails": {
       "order": 1.0,
       "parentTag": "jhg_VotingRightsEntitiesConsolidatedCarryingAmountAssetsAndLiabilitiesNet",
       "weight": 1.0
      },
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_AssetsFairValueDisclosure",
       "weight": 1.0
      },
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Total debt and equity financial instruments including: (1) securities held-to-maturity, (2) trading securities, and (3) securities available-for-sale which are intended to be held for less than one year (4) derivative instruments which are expected to be converted into cash or otherwise disposed of within a year or the normal operating cycle, if longer.",
        "label": "Marketable Securities and Derivative Instruments, Current",
        "terseLabel": "Investment securities",
        "verboseLabel": "Total investment securities"
       }
      }
     },
     "localname": "MarketableSecuritiesAndDerivativeInstrumentsCurrent",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidationViesDetails",
      "http://www.janus.com/role/DisclosureConsolidationVresDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_MarketableSecuritiesAndDerivativesTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This item represents the entire disclosure related to Investment Securities which may consist of all investments in certain debt and equity securities (and other assets).",
        "label": "Marketable Securities and Derivatives [Text Block]",
        "terseLabel": "Investment Securities"
       }
      }
     },
     "localname": "MarketableSecuritiesAndDerivativesTextBlock",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecurities"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jhg_MinorityInterestPeriodIncreaseDecreaseMarketValueOfSeededInvestmentProducts": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the change in value of redeemable minority interest due to change in market value of seeded investment products.",
        "label": "Minority Interest Period Increase (Decrease) Market Value of Seeded Investment Products",
        "terseLabel": "Changes in market value"
       }
      }
     },
     "localname": "MinorityInterestPeriodIncreaseDecreaseMarketValueOfSeededInvestmentProducts",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_MinorityInterestPeriodIncreaseDecreaseOwnershipInterestOfSeededInvestmentProducts": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the change in value of redeemable minority interest due to change in ownership of seeded investment products.",
        "label": "Minority Interest Period Increase (Decrease) Ownership Interest of Seeded Investment Products",
        "terseLabel": "Changes in ownership"
       }
      }
     },
     "localname": "MinorityInterestPeriodIncreaseDecreaseOwnershipInterestOfSeededInvestmentProducts",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_MinorityInterestPeriodIncreaseDecreaseRelatingToForeignCurrencyTranslationOfSeededInvestmentProducts": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the change in value of redeemable minority interest due to foreign currency translation adjustments of seeded investment products.",
        "label": "Minority Interest Period Increase Decrease Relating to Foreign Currency Translation of Seeded Investment Products",
        "terseLabel": "Foreign currency translation"
       }
      }
     },
     "localname": "MinorityInterestPeriodIncreaseDecreaseRelatingToForeignCurrencyTranslationOfSeededInvestmentProducts",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_MinorityInterestRemainingOwnershipPercentage": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the percentage of remaining ownership interest intent to put by a founding member.",
        "label": "Minority Interest, Remaining Ownership Percentage",
        "terseLabel": "Remaining interest (as a percent)"
       }
      }
     },
     "localname": "MinorityInterestRemainingOwnershipPercentage",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "jhg_NetIncomeLossExcludingRedeemableNoncontrollingInterests": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The portion of consolidated profit or loss for the period, net of income taxes, which is attributable to the parent, excluding the effect of redeemable noncontrolling interests.",
        "label": "Net Income (Loss) Excluding Redeemable Noncontrolling Interests",
        "terseLabel": "Net loss (income)"
       }
      }
     },
     "localname": "NetIncomeLossExcludingRedeemableNoncontrollingInterests",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_NewAccountingPronouncementsNotYetAdoptedPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy pertaining to new accounting pronouncements not yet adopted.",
        "label": "New Accounting Pronouncements Not yet Adopted [Policy Text Block]",
        "terseLabel": "Recent Accounting Pronouncements Not Yet Adopted"
       }
      }
     },
     "localname": "NewAccountingPronouncementsNotYetAdoptedPolicyTextBlock",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureBasisOfPresentationAndSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jhg_NoncontrollingInterestIncreaseDecreaseTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of roll forward of noncontrolling interests in consolidated seed investment products.",
        "label": "Noncontrolling Interest Increase (Decrease) [Table Text Block]",
        "terseLabel": "Schedule of movement in redeemable noncontrolling interests in consolidated seeded investment products"
       }
      }
     },
     "localname": "NoncontrollingInterestIncreaseDecreaseTableTextBlock",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jhg_NumberOfInstallmentsForConsiderationPayable": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of equal installments in which contingent consideration in the form of awards will be payable.",
        "label": "Number of Installments for Consideration Payable",
        "terseLabel": "Number of installments"
       }
      }
     },
     "localname": "NumberOfInstallmentsForConsiderationPayable",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsAcquisitionOfKapstreamDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "jhg_OEICAndUnitTrustPayables": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "It represents the Open-Ended Investment Companies and unit trust payables.",
        "label": "O E I C and Unit Trust Payables",
        "terseLabel": "OEIC and unit trust payables"
       }
      }
     },
     "localname": "OEICAndUnitTrustPayables",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_OEICAndUnitTrustReceivables": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "It represents the Open-Ended Investment Companies and unit trust receivables.",
        "label": "O E I C and Unit Trust Receivables",
        "terseLabel": "OEIC and unit trust receivables"
       }
      }
     },
     "localname": "OEICAndUnitTrustReceivables",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_OffsettingAssetsAndLiabilitiesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Offsetting Assets and Liabilities [Line Items]",
        "terseLabel": "Offsetting derivative instruments"
       }
      }
     },
     "localname": "OffsettingAssetsAndLiabilitiesLineItems",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "jhg_OffsettingAssetsAndLiabilitiesTable": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about derivative and financial assets and liabilities that are subject to offsetting, including enforceable master netting arrangements.",
        "label": "Offsetting Assets [Table]"
       }
      }
     },
     "localname": "OffsettingAssetsAndLiabilitiesTable",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "jhg_OtherComprehensiveIncomeActuarialGainLossArisingDuringPeriodNetOfTax": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 2.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after Tax effect on the other comprehensive income relating to actuarial gains (losses).",
        "label": "Other Comprehensive Income Actuarial Gain (Loss) Arising During Period Net of Tax",
        "terseLabel": "Actuarial gains"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeActuarialGainLossArisingDuringPeriodNetOfTax",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_OtherComprehensiveIncomeLossAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Other Comprehensive Income (Loss) [Abstract]",
        "terseLabel": "Other comprehensive income, net of tax"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossAbstract",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossOciDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "jhg_OtherComprehensiveIncomeLossExcludingRedeemableNoncontrollingInterestNetOfTax": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, excluding redeemable non-controlling interest, after tax and reclassification adjustments of other comprehensive income (loss).",
        "label": "Other Comprehensive Income (Loss), Excluding Redeemable Noncontrolling Interest, Net of Tax",
        "terseLabel": "Other comprehensive loss"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossExcludingRedeemableNoncontrollingInterestNetOfTax",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_PaymentsForRepurchaseOfCommonStockForShareBuybackProgram": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash outflow to reacquire common stock for share buyback program during the period.",
        "label": "Purchase of common stock for share buyback program",
        "negatedLabel": "Purchase of common stock for share buyback program"
       }
      }
     },
     "localname": "PaymentsForRepurchaseOfCommonStockForShareBuybackProgram",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_PaymentsForRepurchaseOfCommonStockForStockBasedCompensationPlans": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash outflow to reacquire common stock for stock-based compensation plans during the period.",
        "label": "Payments for Repurchase of Common Stock for Stock based Compensation Plans",
        "negatedLabel": "Purchase of common stock for stock-based compensation plans"
       }
      }
     },
     "localname": "PaymentsForRepurchaseOfCommonStockForStockBasedCompensationPlans",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_PensionContributionsInExcessOfPensionCostsRecognized": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 10.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "It represents the excess of pension contributions over the pension costs recognized during the period.",
        "label": "Pension Contributions in Excess of Pension Costs Recognized",
        "negatedLabel": "Contributions to pension plans in excess of costs recognized"
       }
      }
     },
     "localname": "PensionContributionsInExcessOfPensionCostsRecognized",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_PercentageOfOwnershipSold": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the percentage of ownership of the company disposed of.",
        "label": "Percentage of Ownership Sold",
        "terseLabel": "Ownership sold (as a percent)"
       }
      }
     },
     "localname": "PercentageOfOwnershipSold",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsDetails",
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "jhg_PeriodForCarrybackOfFederalNetOperatingLosses": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The period of time for the carryback of federal net operating losses per the CARES Act.",
        "label": "Period for Carryback of Federal Net Operating Losses",
        "terseLabel": "Carryback period for Federal Net Operating Losses per the CARES Act"
       }
      }
     },
     "localname": "PeriodForCarrybackOfFederalNetOperatingLosses",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "jhg_PeriodOfPerformanceOfInvesteeForRecognizingConsideration": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Period of performance taken to considered for calculation of consideration of sale of investee assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Period of Performance of Investee for Recognizing Consideration",
        "terseLabel": "Period of performance of investee for recognizing consideration",
        "verboseLabel": "Period of time for earnout payments"
       }
      }
     },
     "localname": "PeriodOfPerformanceOfInvesteeForRecognizingConsideration",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "jhg_PooledInvestmentFundsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the information relating to pooled investment funds.",
        "label": "Pooled Investment Funds [Member]",
        "terseLabel": "Pooled investment funds"
       }
      }
     },
     "localname": "PooledInvestmentFundsMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_PostEmploymentBenefitsAssetNoncurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 5.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "For a classified balance sheet, the carrying amount as of the balance sheet date of the portion of the assets recognized for post employment benefits which are non current.",
        "label": "Post-Employment Benefits Asset Noncurrent",
        "terseLabel": "Retirement benefit asset, net"
       }
      }
     },
     "localname": "PostEmploymentBenefitsAssetNoncurrent",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_ProceedsFromGeneva": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 7.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash inflow associated with the amount received from the sale of Geneva.",
        "label": "Proceeds From Geneva",
        "terseLabel": "Proceeds from sale of Geneva"
       }
      }
     },
     "localname": "ProceedsFromGeneva",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_ProceedsFromPaymentsForInvestmentSecuritiesByConsolidatedSeededInvestmentProductsNet": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash flows associated with the acquisition or sale of investment securities by consolidated seeded investment products by the entity during the period.",
        "label": "Proceeds from (Payments for) Investment Securities by Consolidated Seeded Investment Products, Net",
        "terseLabel": "Investment securities by consolidated seeded investment products, net"
       }
      }
     },
     "localname": "ProceedsFromPaymentsForInvestmentSecuritiesByConsolidatedSeededInvestmentProductsNet",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_ProceedsFromSaleOfBusinessContingentConsideration": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of contingent consideration received from sale of business.",
        "label": "Proceeds From Sale of Business Contingent Consideration",
        "terseLabel": "Contingent consideration payment"
       }
      }
     },
     "localname": "ProceedsFromSaleOfBusinessContingentConsideration",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_ProceedsFromSalesSettlementsOrMaturitiesOfMarketableSecuritiesAndDerivatives": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash inflow associated with the aggregate amount received by the entity through sales, settlements or maturities of marketable securities and derivatives (trading, held-to-maturity, or available-for-sale) during the period.",
        "label": "Proceeds from Sales, Settlements or Maturities of Marketable Securities and Derivatives",
        "verboseLabel": "Sales, settlements and maturities"
       }
      }
     },
     "localname": "ProceedsFromSalesSettlementsOrMaturitiesOfMarketableSecuritiesAndDerivatives",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_ProceedsFromThirdPartyInvestmentsInSeededInvestmentProductsNetOfRedemptions": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash inflow (outflow) from third-party investments in seeded investment products, net of redemptions.",
        "label": "Proceeds from Third-party Investments in Seeded Investment Products, Net of Redemptions",
        "verboseLabel": "Third-party sales (redemptions) in consolidated seeded investment products, net"
       }
      }
     },
     "localname": "ProceedsFromThirdPartyInvestmentsInSeededInvestmentProductsNetOfRedemptions",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_ProceedsFromVolantis": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash inflow associated with the amount received from sale of Volantis.",
        "label": "Proceeds from Volantis",
        "terseLabel": "Proceeds from sale of Volantis"
       }
      }
     },
     "localname": "ProceedsFromVolantis",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_PurchasesSettlementsAndMaturitiesOfMarketableSecuritiesAndDerivatives": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash outflow from purchases, settlements or maturities of trading, available-for-sale securities and held-to-maturity securities and derivatives.",
        "label": "Purchases, Settlements and Maturities of Marketable Securities and Derivatives",
        "negatedLabel": "Investment securities, net",
        "negatedTerseLabel": "Purchases and settlements"
       }
      }
     },
     "localname": "PurchasesSettlementsAndMaturitiesOfMarketableSecuritiesAndDerivatives",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_ReclassificationForItemsIncludedInNetIncomeMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the reclassification adjustment from accumulated other comprehensive income (loss).",
        "label": "Reclassification For Items Included In Net Income [Member]",
        "terseLabel": "Reclassification to net income"
       }
      }
     },
     "localname": "ReclassificationForItemsIncludedInNetIncomeMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossOciDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_ReconciliationOfCashAndCashEquivalentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "n/a",
        "label": "Reconciliation of Cash and Cash Equivalents [Abstract]",
        "terseLabel": "Reconciliation of cash and cash equivalents:"
       }
      }
     },
     "localname": "ReconciliationOfCashAndCashEquivalentsAbstract",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "jhg_RedeemableNoncontrollingInterestInVotingRightsEntities": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/DisclosureConsolidationVresDetails": {
       "order": 1.0,
       "parentTag": "jhg_VotingRightsEntitiesConsolidatedAssetsAndLiabilitiesExcludingNoncontrollingInterestNet",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Portion of equity (net assets) in a voting rights entities (VRE) not attributable, directly or indirectly, to the parent entity. That is, this is the portion of equity in a VRE that is attributable to the redeemable noncontrolling interest (previously referred to as minority interest).",
        "label": "Redeemable Noncontrolling Interest In Voting Rights Entities",
        "negatedLabel": "Redeemable noncontrolling interests in consolidated VREs"
       }
      }
     },
     "localname": "RedeemableNoncontrollingInterestInVotingRightsEntities",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidationVresDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_RestrictedStockAndUnvestedNonparticipatingStockAwardMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents information pertaining to unvested nonparticipation restricted stock.",
        "label": "Restricted Stock And Unvested Nonparticipating Stock Award [Member]",
        "terseLabel": "Unvested nonparticipating stock awards"
       }
      }
     },
     "localname": "RestrictedStockAndUnvestedNonparticipatingStockAwardMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_RightOfUseOperatingLeaseImpairmentLoss": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 7.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of loss from impairment of right-of-use asset from operating lease.",
        "label": "Right of Use Operating Lease, Impairment Loss",
        "terseLabel": "Impairment of right-of-use operating asset"
       }
      }
     },
     "localname": "RightOfUseOperatingLeaseImpairmentLoss",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_ScheduleOfDerivativeInstrumentsDenominatedInForeignCurrencyGainsLossesInStatementOfFinancialPerformanceTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the amount of gains and losses related to hedged trading securities denominated in a foreign currency and associated foreign currency forward contracts reported in the statement of financial performance.",
        "label": "Schedule of Derivative Instruments Denominated in Foreign Currency Gains (Losses) in Statement of Financial Performance [Text Block]",
        "verboseLabel": "Schedule of net foreign currency translation gains (losses) on hedged seed investments denominated in foreign currencies and net gains (losses) associated with foreign currency forward contracts under net investment hedging"
       }
      }
     },
     "localname": "ScheduleOfDerivativeInstrumentsDenominatedInForeignCurrencyGainsLossesInStatementOfFinancialPerformanceTextBlock",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jhg_ScheduleOfEffectiveIncomeTaxRatesTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the effective income tax rate of the Company.",
        "label": "Schedule of Effective Income Tax Rates [Table Text Block]",
        "terseLabel": "Schedule of effective income tax rates"
       }
      }
     },
     "localname": "ScheduleOfEffectiveIncomeTaxRatesTableTextBlock",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jhg_ScheduleOfGoodwillAndIntangibleAssetsTable": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule of goodwill and intangible assets.",
        "label": "Schedule of Goodwill and Intangible Assets [Table]"
       }
      }
     },
     "localname": "ScheduleOfGoodwillAndIntangibleAssetsTable",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "jhg_ScheduleOfIntangibleAssetsAndGoodwillLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "No definition available.",
        "label": "Schedule of Intangible Assets and Goodwill [Line Items]",
        "terseLabel": "Goodwill and intangible assets"
       }
      }
     },
     "localname": "ScheduleOfIntangibleAssetsAndGoodwillLineItems",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "jhg_ScheduleOfNonredeemableNoncontrollingInterestTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure related to nonredeemable noncontrolling interests.",
        "label": "Schedule of Nonredeemable Noncontrolling Interest [Table Text Block]",
        "terseLabel": "Summary of nonredeemable noncontrolling interests"
       }
      }
     },
     "localname": "ScheduleOfNonredeemableNoncontrollingInterestTableTextBlock",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jhg_ScheduleOfRealizedGainLossOnTradingSecuritiesTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the net unrealized gains (losses) on trading securities.",
        "label": "Schedule Of Realized Gain Loss On Trading Securities Table Text Block",
        "verboseLabel": "Schedule of net unrealized gains on trading securities"
       }
      }
     },
     "localname": "ScheduleOfRealizedGainLossOnTradingSecuritiesTableTextBlock",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jhg_SeededHedgeDerivatesMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the information pertaining to seeded hedge derivates.",
        "label": "Seeded Hedge Derivates [Member]",
        "terseLabel": "Seed hedge derivatives"
       }
      }
     },
     "localname": "SeededHedgeDerivatesMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_SeededInvestmentProductsAndDerivativesMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the information pertaining to seeded investment products and derivatives.",
        "label": "Seeded Investment Products And Derivatives [Member]",
        "terseLabel": "Seeded investment products and derivatives"
       }
      }
     },
     "localname": "SeededInvestmentProductsAndDerivativesMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_SeededInvestmentProductsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the information pertaining to seeded investment products.",
        "label": "Seeded Investment Products [Member]",
        "terseLabel": "Seeded investment products"
       }
      }
     },
     "localname": "SeededInvestmentProductsMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables",
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsNonredeemableDetails",
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_SeniorNotes4.875PercentDue2025Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents senior notes that bear an interest rate of 4.875 percent and will mature in 2025.",
        "label": "Senior Notes4.875 Percent Due2025 [Member]",
        "terseLabel": "4.875% Senior Notes due 2025"
       }
      }
     },
     "localname": "SeniorNotes4.875PercentDue2025Member",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_SeparatelyManagedAccountsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This category includes information about individual managed investment accounts offered typically by a brokerage firm through one of their brokers or financial consultants and managed by independent investment management firms.",
        "label": "Separately Managed Accounts [Member]",
        "terseLabel": "Separate accounts"
       }
      }
     },
     "localname": "SeparatelyManagedAccountsMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_ShareBasedCompensationArrangementByShareBasedPaymentAwardTotal": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The total amount of the share-based compensation awards granted during the period (for example, shares of stock, units, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Total",
        "terseLabel": "Long-term incentive awards granted"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardTotal",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureLongTermIncentiveAndEmployeeCompensationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_StockRepurchasedForStockBasedCompensationPlanDuringPeriodValue": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Equity impact of the value of stock that has been repurchased for Stock based compensation plan during the period.",
        "label": "Stock Repurchased for Stock based Compensation Plan During Period, Value",
        "negatedLabel": "Purchase of common stock for stock-based compensation plans"
       }
      }
     },
     "localname": "StockRepurchasedForStockBasedCompensationPlanDuringPeriodValue",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_ThirdPartyOwnershipInterestsInSeededInvestmentProductsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents information pertaining to third-party ownership interests in seeded investment products.",
        "label": "Third Party Ownership Interests In Seeded Investment Products [Member]",
        "terseLabel": "Third-party ownership interests in seeded investment products"
       }
      }
     },
     "localname": "ThirdPartyOwnershipInterestsInSeededInvestmentProductsMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_TotalReturnSwapsAndIndexSwapsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents information pertaining to total return swaps and index swaps.",
        "label": "Total Return Swaps And Index Swaps [Member]",
        "terseLabel": "Total return swaps and index swaps"
       }
      }
     },
     "localname": "TotalReturnSwapsAndIndexSwapsMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_UnsecuredRevolvingCreditFacilityMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A contractual arrangement with a lender under which unsecured borrowings can be made up to a specific amount at any point in time, and under which borrowings outstanding may be either short-term or long-term, depending upon the particulars.",
        "label": "Unsecured Revolving Credit Facility [Member]",
        "terseLabel": "Credit Facility"
       }
      }
     },
     "localname": "UnsecuredRevolvingCreditFacilityMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_VariableInterestEntitiesVotingRightsEntitiesConsolidationDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "n/a",
        "label": "Consolidation"
       }
      }
     },
     "localname": "VariableInterestEntitiesVotingRightsEntitiesConsolidationDisclosureAbstract",
     "nsuri": "http://www.janus.com/20200630",
     "xbrltype": "stringItemType"
    },
    "jhg_VariableInterestEntitiesVotingRightsEntitiesConsolidationDisclosureTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for variable interest entities (VIE) and voting right entities (VRE).",
        "label": "Variable Interest Entities, Voting Rights Entities Consolidation Disclosure [Text Block]",
        "terseLabel": "Consolidation"
       }
      }
     },
     "localname": "VariableInterestEntitiesVotingRightsEntitiesConsolidationDisclosureTextBlock",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidation"
     ],
     "xbrltype": "textBlockItemType"
    },
    "jhg_VariableRightsEntityNotPrimaryBeneficiaryAggregatedDisclosureMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Aggregated disclosures of similar Variable Rights Entities (VRE) which are not included in the consolidated financial statements of the entity because the entity does not have a controlling financial interest (not the primary beneficiary). Such disclosures may include how similar entities are aggregated, if separate reporting would not provide more useful information.",
        "label": "Variable Rights Entity Not Primary Beneficiary Aggregated Disclosure [Member]",
        "terseLabel": "Unconsolidated VREs"
       }
      }
     },
     "localname": "VariableRightsEntityNotPrimaryBeneficiaryAggregatedDisclosureMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidationVresDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_VariableRightsEntityPrimaryBeneficiaryAggregatedDisclosureMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosures of similar consolidated Variable Rights Entities (VRE), in aggregate, including how similar entities are aggregated, if separate reporting would not provide more useful information.",
        "label": "Variable Rights Entity Primary Beneficiary Aggregated Disclosure [Member]",
        "terseLabel": "Consolidated VREs"
       }
      }
     },
     "localname": "VariableRightsEntityPrimaryBeneficiaryAggregatedDisclosureMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidationVresDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_VelocitySharesEtnMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Related to VelocityShares ETNs.",
        "label": "Velocity Shares Etn [Member]",
        "terseLabel": "VelocityShares ETNs"
       }
      }
     },
     "localname": "VelocitySharesEtnMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_VestingOfStockBasedCompensationPlansValue": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "It represents the vesting amount of stock-based compensation plans.",
        "label": "Vesting of Stock-Based Compensation Plans Value",
        "terseLabel": "Vesting of stock-based compensation plans"
       }
      }
     },
     "localname": "VestingOfStockBasedCompensationPlansValue",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_VolantisMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents information pertaining to Volantis.",
        "label": "Volantis [Member]",
        "terseLabel": "Volantis"
       }
      }
     },
     "localname": "VolantisMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "jhg_VotingRightsEntitiesConsolidatedAssetsAndLiabilitiesExcludingNoncontrollingInterestNet": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/DisclosureConsolidationVresDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The net carrying amount of the net interest in consolidated voting rights entities assets and liabilities excluding noncontrolling interest.",
        "label": "Voting Rights Entities Consolidated Assets And Liabilities Excluding Noncontrolling Interest, Net",
        "totalLabel": "JHG's net interest in consolidated VREs"
       }
      }
     },
     "localname": "VotingRightsEntitiesConsolidatedAssetsAndLiabilitiesExcludingNoncontrollingInterestNet",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidationVresDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_VotingRightsEntitiesConsolidatedCarryingAmountAssetsAndLiabilitiesNet": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/DisclosureConsolidationVresDetails": {
       "order": 2.0,
       "parentTag": "jhg_VotingRightsEntitiesConsolidatedAssetsAndLiabilitiesExcludingNoncontrollingInterestNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The net carrying amount of the Voting Rights Entity's assets and liabilities included in the reporting entity's statement of financial position.",
        "label": "Voting Rights Entities Consolidated Carrying Amount Assets And Liabilities Net",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "VotingRightsEntitiesConsolidatedCarryingAmountAssetsAndLiabilitiesNet",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidationVresDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "jhg_VotingRightsEntityPrimaryBeneficiaryAggregatedDisclosureMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosures of similar consolidated Voting Rights Entities (VRE), in aggregate, including how similar entities are aggregated, if separate reporting would not provide more useful information.",
        "label": "Voting Rights Entity Primary Beneficiary Aggregated Disclosure [Member]",
        "terseLabel": "Consolidated VREs"
       }
      }
     },
     "localname": "VotingRightsEntityPrimaryBeneficiaryAggregatedDisclosureMember",
     "nsuri": "http://www.janus.com/20200630",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ConsolidatedEntitiesAxis": {
     "auth_ref": [
      "r380"
     ],
     "lang": {
      "en-US": {
       "role": {
        "label": "Consolidated Entities [Axis]"
       }
      }
     },
     "localname": "ConsolidatedEntitiesAxis",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails",
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsNonredeemableDetails",
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ConsolidatedEntitiesDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Consolidated Entities [Domain]",
        "terseLabel": "Consolidated Entities [Domain]"
       }
      }
     },
     "localname": "ConsolidatedEntitiesDomain",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails",
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsNonredeemableDetails",
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ConsolidatedEntityExcludingVariableInterestEntitiesVIEMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Consolidated Entity Excluding Variable Interest Entities V I E [Member]",
        "terseLabel": "Consolidated excluding VIEs"
       }
      }
     },
     "localname": "ConsolidatedEntityExcludingVariableInterestEntitiesVIEMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_MaximumMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Maximum [Member]",
        "terseLabel": "Maximum"
       }
      }
     },
     "localname": "MaximumMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsAcquisitionOfKapstreamDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails",
      "http://www.janus.com/role/DisclosureLongTermIncentiveAndEmployeeCompensationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_MinimumMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Minimum [Member]",
        "terseLabel": "Minimum"
       }
      }
     },
     "localname": "MinimumMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsDetails",
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails",
      "http://www.janus.com/role/DisclosureLongTermIncentiveAndEmployeeCompensationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ProductOrServiceAxis": {
     "auth_ref": [
      "r126",
      "r194",
      "r195",
      "r361",
      "r362"
     ],
     "lang": {
      "en-US": {
       "role": {
        "label": "Product and Service [Axis]"
       }
      }
     },
     "localname": "ProductOrServiceAxis",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ProductsAndServicesDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Products And Services [Domain]",
        "terseLabel": "Product and Service [Domain]"
       }
      }
     },
     "localname": "ProductsAndServicesDomain",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RangeAxis": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Range [Axis]"
       }
      }
     },
     "localname": "RangeAxis",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsDetails",
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsAcquisitionOfKapstreamDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails",
      "http://www.janus.com/role/DisclosureLongTermIncentiveAndEmployeeCompensationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_RangeMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Range [Member]",
        "terseLabel": "Range [Domain]"
       }
      }
     },
     "localname": "RangeMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsDetails",
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsAcquisitionOfKapstreamDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails",
      "http://www.janus.com/role/DisclosureLongTermIncentiveAndEmployeeCompensationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RestatementAdjustmentMember": {
     "auth_ref": [
      "r99",
      "r101",
      "r102",
      "r103"
     ],
     "lang": {
      "en-US": {
       "role": {
        "label": "Restatement Adjustment [Member]",
        "terseLabel": "Adjustments"
       }
      }
     },
     "localname": "RestatementAdjustmentMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RestatementAxis": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Restatement [Axis]"
       }
      }
     },
     "localname": "RestatementAxis",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_RestatementDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Restatement [Domain]",
        "terseLabel": "Restatement [Domain]"
       }
      }
     },
     "localname": "RestatementDomain",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ScenarioForecastMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Scenario Forecast [Member]",
        "terseLabel": "Forecast"
       }
      }
     },
     "localname": "ScenarioForecastMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ScenarioPreviouslyReportedMember": {
     "auth_ref": [
      "r101",
      "r102",
      "r103"
     ],
     "lang": {
      "en-US": {
       "role": {
        "label": "Scenario Previously Reported [Member]",
        "terseLabel": "Previously reported"
       }
      }
     },
     "localname": "ScenarioPreviouslyReportedMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ScenarioUnspecifiedDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Scenario Unspecified [Domain]",
        "terseLabel": "Scenario, Unspecified [Domain]"
       }
      }
     },
     "localname": "ScenarioUnspecifiedDomain",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_SegmentGeographicalDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Segment Geographical [Domain]",
        "terseLabel": "Geographical [Domain]"
       }
      }
     },
     "localname": "SegmentGeographicalDomain",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_StatementGeographicalAxis": {
     "auth_ref": [
      "r127",
      "r194",
      "r196",
      "r363",
      "r378",
      "r379"
     ],
     "lang": {
      "en-US": {
       "role": {
        "label": "Geographical [Axis]"
       }
      }
     },
     "localname": "StatementGeographicalAxis",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_StatementScenarioAxis": {
     "auth_ref": [
      "r177",
      "r320"
     ],
     "lang": {
      "en-US": {
       "role": {
        "label": "Scenario [Axis]"
       }
      }
     },
     "localname": "StatementScenarioAxis",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_SubsidiariesMember": {
     "auth_ref": [
      "r208",
      "r318",
      "r319"
     ],
     "lang": {
      "en-US": {
       "role": {
        "label": "Subsidiaries [Member]",
        "terseLabel": "Intech"
       }
      }
     },
     "localname": "SubsidiariesMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsNonredeemableDetails",
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AOCIAttributableToParentNetOfTaxRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]",
        "terseLabel": "Changes in accumulated other comprehensive loss, net of tax"
       }
      }
     },
     "localname": "AOCIAttributableToParentNetOfTaxRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccountingStandardsUpdate201815Member": {
     "auth_ref": [
      "r165",
      "r166"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Accounting Standards Update 2018-15 Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (a consensus of the FASB Emerging Issues Task Force).",
        "label": "Accounting Standards Update201815 [Member]",
        "terseLabel": "Accounting Standards Update 2018-15"
       }
      }
     },
     "localname": "AccountingStandardsUpdate201815Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureBasisOfPresentationAndSignificantAccountingPoliciesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent": {
     "auth_ref": [
      "r34"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureConsolidationVresDetails": {
       "order": 4.0,
       "parentTag": "jhg_VotingRightsEntitiesConsolidatedCarryingAmountAssetsAndLiabilitiesNet",
       "weight": -1.0
      },
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.",
        "label": "Accounts Payable and Accrued Liabilities, Current",
        "negatedLabel": "Accounts payable and accrued liabilities",
        "verboseLabel": "Accounts payable and accrued liabilities"
       }
      }
     },
     "localname": "AccountsPayableAndAccruedLiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidationVresDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember": {
     "auth_ref": [
      "r52",
      "r57",
      "r58",
      "r207",
      "r262"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Accumulated other comprehensive (income) loss related to defined benefit plans attributable to the parent.",
        "label": "Accumulated Defined Benefit Plans Adjustment [Member]",
        "terseLabel": "Retirement benefit asset, net"
       }
      }
     },
     "localname": "AccumulatedDefinedBenefitPlansAdjustmentMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails",
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossOciDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Accumulated Other Comprehensive Income (Loss) [Line Items]",
        "terseLabel": "Other Comprehensive Loss"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeLossLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax": {
     "auth_ref": [
      "r54",
      "r56",
      "r57"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.",
        "label": "Accumulated Other Comprehensive Income (Loss), Net of Tax",
        "verboseLabel": "Accumulated other comprehensive loss, net of tax"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeLossNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeLossTable": {
     "auth_ref": [],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails",
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossOciDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeMember": {
     "auth_ref": [
      "r53",
      "r57",
      "r58",
      "r262"
     ],
     "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": "Accumulated Other Comprehensive Income [Member]",
        "terseLabel": "Accumulated other comprehensive loss"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails",
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossOciDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccumulatedTranslationAdjustmentMember": {
     "auth_ref": [
      "r50",
      "r57",
      "r58",
      "r262"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Accumulated other comprehensive income (loss) resulting from foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature, attributable to the parent.",
        "label": "Accumulated Translation Adjustment [Member]",
        "terseLabel": "Foreign currency translation adjustments"
       }
      }
     },
     "localname": "AccumulatedTranslationAdjustmentMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails",
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossOciDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AdditionalPaidInCapital": {
     "auth_ref": [
      "r26"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "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. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of additional paid-in capital associated with common and preferred stock. For additional paid-in capital associated with only common stock, use the element additional paid in capital, common stock. For additional paid-in capital associated with only preferred stock, use the element additional paid in capital, preferred stock.",
        "label": "Additional Paid in Capital",
        "terseLabel": "Additional paid-in-capital"
       }
      }
     },
     "localname": "AdditionalPaidInCapital",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AdditionalPaidInCapitalMember": {
     "auth_ref": [],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AdjustmentsForNewAccountingPronouncementsAxis": {
     "auth_ref": [
      "r98"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by new accounting pronouncement.",
        "label": "Adjustments for New Accounting Pronouncements [Axis]"
       }
      }
     },
     "localname": "AdjustmentsForNewAccountingPronouncementsAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureBasisOfPresentationAndSignificantAccountingPoliciesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]",
        "terseLabel": "Adjustments to reconcile net income (loss) to net cash provided by operating activities:"
       }
      }
     },
     "localname": "AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue": {
     "auth_ref": [
      "r215",
      "r216",
      "r221",
      "r222"
     ],
     "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": "Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition",
        "terseLabel": "Stock-based compensation plan expense"
       }
      }
     },
     "localname": "AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AllocatedShareBasedCompensationExpense": {
     "auth_ref": [
      "r216",
      "r219",
      "r220"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 2.0,
       "parentTag": "us-gaap_CostsAndExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.",
        "label": "Allocated Share-based Compensation Expense",
        "terseLabel": "Long-term incentive plans"
       }
      }
     },
     "localname": "AllocatedShareBasedCompensationExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AlternativeInvestmentMeasurementInput": {
     "auth_ref": [
      "r290"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Value of input used to measure alternative investment.",
        "label": "Alternative Investment, Measurement Input",
        "terseLabel": "Asset, measurement input"
       }
      }
     },
     "localname": "AlternativeInvestmentMeasurementInput",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "us-gaap_AlternativeInvestmentMeasurementInputExtensibleList": {
     "auth_ref": [
      "r289",
      "r302"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Indicates measurement input for alternative investment.",
        "label": "Alternative Investment, Measurement Input [Extensible List]"
       }
      }
     },
     "localname": "AlternativeInvestmentMeasurementInputExtensibleList",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "extensibleListItemType"
    },
    "us-gaap_AmortizationOfIntangibleAssets": {
     "auth_ref": [
      "r88",
      "r153",
      "r160"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.",
        "label": "Amortization of Intangible Assets",
        "negatedTerseLabel": "Amortization"
       }
      }
     },
     "localname": "AmortizationOfIntangibleAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount": {
     "auth_ref": [
      "r118"
     ],
     "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": "Number of anti-dilutive securities that have not been included in the calculation of weighted average diluted shares outstanding"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis": {
     "auth_ref": [
      "r118"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of antidilutive security.",
        "label": "Antidilutive Securities [Axis]"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "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": "Anti-dilutive securities that have not been included in the calculation of weighted average diluted shares outstanding"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AntidilutiveSecuritiesNameDomain": {
     "auth_ref": [
      "r118"
     ],
     "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]",
        "terseLabel": "Antidilutive Securities, Name [Domain]"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_Assets": {
     "auth_ref": [
      "r124",
      "r341",
      "r352"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Assets [Abstract]",
        "terseLabel": "ASSETS"
       }
      }
     },
     "localname": "AssetsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AssetsCurrent": {
     "auth_ref": [
      "r17",
      "r18",
      "r46"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.",
        "label": "Assets, Current",
        "totalLabel": "Total current assets"
       }
      }
     },
     "localname": "AssetsCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetsCurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Assets, Current [Abstract]",
        "terseLabel": "Current assets:"
       }
      }
     },
     "localname": "AssetsCurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AssetsFairValueDisclosure": {
     "auth_ref": [
      "r285"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "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",
        "totalLabel": "Total assets"
       }
      }
     },
     "localname": "AssetsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetsNoncurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Assets, Noncurrent [Abstract]",
        "terseLabel": "Non-current assets:"
       }
      }
     },
     "localname": "AssetsNoncurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BasisOfAccountingPolicyPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for basis of accounting, or basis of presentation, used to prepare the financial statements (for example, US Generally Accepted Accounting Principles, Other Comprehensive Basis of Accounting, IFRS).",
        "label": "Basis of Accounting, Policy [Policy Text Block]",
        "terseLabel": "Basis of Presentation"
       }
      }
     },
     "localname": "BasisOfAccountingPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureBasisOfPresentationAndSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock": {
     "auth_ref": [
      "r97"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for the basis of presentation and significant accounting policies concepts. Basis of presentation describes the underlying basis used to prepare the financial statements (for example, US Generally Accepted Accounting Principles, Other Comprehensive Basis of Accounting, IFRS).  Accounting policies describe all significant accounting policies of the reporting entity.",
        "label": "Basis of Presentation and Significant Accounting Policies [Text Block]",
        "terseLabel": "Basis of Presentation and Significant Accounting Policies"
       }
      }
     },
     "localname": "BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureBasisOfPresentationAndSignificantAccountingPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_BusinessAcquisitionAcquireeDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Identification of the acquiree in a material business combination (or series of individually immaterial business combinations), which may include the name or other type of identification of the acquiree.",
        "label": "Business Acquisition Acquiree [Domain]",
        "terseLabel": "Business Acquisition, Acquiree [Domain]"
       }
      }
     },
     "localname": "BusinessAcquisitionAcquireeDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsAcquisitionOfKapstreamDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsContingentConsiderationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_BusinessAcquisitionAxis": {
     "auth_ref": [
      "r243",
      "r244"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by business combination or series of individually immaterial business combinations.",
        "label": "Business Acquisition [Axis]"
       }
      }
     },
     "localname": "BusinessAcquisitionAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsAcquisitionOfKapstreamDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsContingentConsiderationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BusinessAcquisitionContingentConsiderationLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Business Acquisition, Contingent Consideration [Line Items]",
        "terseLabel": "Contingent Consideration"
       }
      }
     },
     "localname": "BusinessAcquisitionContingentConsiderationLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsContingentConsiderationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BusinessAcquisitionLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Business Acquisition [Line Items]",
        "verboseLabel": "Business acquisition"
       }
      }
     },
     "localname": "BusinessAcquisitionLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsAcquisitionOfKapstreamDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired": {
     "auth_ref": [
      "r242"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage of voting equity interests acquired at the acquisition date in the business combination.",
        "label": "Business Acquisition, Percentage of Voting Interests Acquired",
        "terseLabel": "Ownership interest acquired (as a percent)"
       }
      }
     },
     "localname": "BusinessAcquisitionPercentageOfVotingInterestsAcquired",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsAcquisitionOfKapstreamDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1": {
     "auth_ref": [
      "r87",
      "r252"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 9.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement.",
        "label": "Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability",
        "terseLabel": "Contingent consideration adjustment"
       }
      }
     },
     "localname": "BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsAcquisitionOfKapstreamDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationContingentConsiderationAsset": {
     "auth_ref": [
      "r248",
      "r249",
      "r250"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_AssetsFairValueDisclosure",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of asset recognized arising from contingent consideration in a business combination.",
        "label": "Business Combination, Contingent Consideration, Asset",
        "terseLabel": "Contingent consideration",
        "verboseLabel": "Fair value of contingent consideration"
       }
      }
     },
     "localname": "BusinessCombinationContingentConsiderationAsset",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsDetails",
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationContingentConsiderationLiability": {
     "auth_ref": [
      "r247",
      "r249",
      "r250"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_LiabilitiesFairValueDisclosure",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of liability recognized arising from contingent consideration in a business combination.",
        "label": "Business Combination, Contingent Consideration, Liability",
        "positiveLabel": "Fair value of contingent consideration liability",
        "terseLabel": "Contingent consideration"
       }
      }
     },
     "localname": "BusinessCombinationContingentConsiderationLiability",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsAcquisitionOfKapstreamDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsContingentConsiderationDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationContingentConsiderationLiabilityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Business Combination, Contingent Consideration, Liability [Abstract]",
        "terseLabel": "Fair value included in:"
       }
      }
     },
     "localname": "BusinessCombinationContingentConsiderationLiabilityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsContingentConsiderationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CapitalizedComputerSoftwareAdditions": {
     "auth_ref": [
      "r154"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Additions made to capitalized computer software costs during the period.",
        "label": "Capitalized Computer Software, Additions",
        "terseLabel": "Capitalized implementation costs"
       }
      }
     },
     "localname": "CapitalizedComputerSoftwareAdditions",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureBasisOfPresentationAndSignificantAccountingPoliciesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CarryingReportedAmountFairValueDisclosureMember": {
     "auth_ref": [
      "r300",
      "r301"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Measured as reported on the statement of financial position (balance sheet).",
        "label": "Carrying Reported Amount Fair Value Disclosure [Member]",
        "terseLabel": "Carrying value"
       }
      }
     },
     "localname": "CarryingReportedAmountFairValueDisclosureMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CashAndCashEquivalentsAtCarryingValue": {
     "auth_ref": [
      "r16",
      "r31",
      "r90"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureConsolidationVresDetails": {
       "order": 2.0,
       "parentTag": "jhg_VotingRightsEntitiesConsolidatedCarryingAmountAssetsAndLiabilitiesNet",
       "weight": 1.0
      },
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. 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",
        "terseLabel": "Cash and cash equivalents",
        "verboseLabel": "Cash and cash equivalents"
       }
      }
     },
     "localname": "CashAndCashEquivalentsAtCarryingValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidationVresDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashAndCashEquivalentsAtCarryingValueAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Cash and Cash Equivalents, at Carrying Value [Abstract]",
        "terseLabel": "Cash and cash equivalents:"
       }
      }
     },
     "localname": "CashAndCashEquivalentsAtCarryingValueAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CashAndCashEquivalentsFairValueDisclosure": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_AssetsFairValueDisclosure",
       "weight": 1.0
      }
     },
     "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",
        "terseLabel": "Cash equivalents"
       }
      }
     },
     "localname": "CashAndCashEquivalentsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashAndCashEquivalentsPeriodIncreaseDecreaseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Cash and Cash Equivalents, Period Increase (Decrease) [Abstract]",
        "terseLabel": "CASH FLOWS PROVIDED BY (USED FOR):"
       }
      }
     },
     "localname": "CashAndCashEquivalentsPeriodIncreaseDecreaseAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents": {
     "auth_ref": [
      "r84",
      "r90",
      "r92"
     ],
     "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": "At end of period",
        "periodStartLabel": "At beginning of period",
        "terseLabel": "Cash and cash equivalents"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect": {
     "auth_ref": [
      "r84",
      "r306"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "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 change"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ClassificationOfVariableInterestEntityDomain": {
     "auth_ref": [
      "r264",
      "r265",
      "r266",
      "r267"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Categorization of Variable Interest Entities (VIE) for consolidation and (or) disclosure purposes, whether individually or in aggregate, by: (1) VIEs consolidated because the entity is the primary beneficiary, (2) VIEs not consolidated because the entity is not the primary beneficiary, and (3) VIEs or potential VIEs that are not consolidated because necessary information is not available. In general, a VIE is a corporation, partnership, trust, or any other legal structure used for business purposes that either (a) does not have equity investors with voting rights or (b) has equity investors that do not provide sufficient financial resources for the entity to support its activities. A VIE often holds financial assets, including loans or receivables, real estate or other property. A VIE may be essentially passive or it may engage in research and development or other activities on behalf of another company.",
        "label": "Classification Of Variable Interest Entity [Domain]",
        "terseLabel": "Variable Interest Entity, Classification [Domain]"
       }
      }
     },
     "localname": "ClassificationOfVariableInterestEntityDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidationViesDetails",
      "http://www.janus.com/role/DisclosureConsolidationVresDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommitmentsAndContingencies": {
     "auth_ref": [
      "r41",
      "r176",
      "r346",
      "r358"
     ],
     "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 (See Note 14)"
       }
      }
     },
     "localname": "CommitmentsAndContingencies",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CommitmentsAndContingenciesDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Commitments and Contingencies"
       }
      }
     },
     "localname": "CommitmentsAndContingenciesDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_CommitmentsAndContingenciesDisclosureTextBlock": {
     "auth_ref": [
      "r175",
      "r178"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureCommitmentsAndContingencies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CommonStockDividendsPerShareCashPaid": {
     "auth_ref": [
      "r190"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Aggregate dividends paid during the period for each share of common stock outstanding.",
        "label": "Common Stock, Dividends, Per Share, Cash Paid",
        "terseLabel": "Dividends paid (per share)"
       }
      }
     },
     "localname": "CommonStockDividendsPerShareCashPaid",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquityParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_CommonStockDividendsPerShareDeclared": {
     "auth_ref": [
      "r190"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Aggregate dividends declared during the period for each share of common stock outstanding.",
        "label": "Common Stock, Dividends, Per Share, Declared",
        "terseLabel": "Cash dividend declared (in dollars per share)"
       }
      }
     },
     "localname": "CommonStockDividendsPerShareDeclared",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_CommonStockMember": {
     "auth_ref": [],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommonStockParOrStatedValuePerShare": {
     "auth_ref": [
      "r25"
     ],
     "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 (in dollars per share)"
       }
      }
     },
     "localname": "CommonStockParOrStatedValuePerShare",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_CommonStockSharesAuthorized": {
     "auth_ref": [
      "r25"
     ],
     "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, shares authorized"
       }
      }
     },
     "localname": "CommonStockSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockSharesIssued": {
     "auth_ref": [
      "r25"
     ],
     "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, shares issued"
       }
      }
     },
     "localname": "CommonStockSharesIssued",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockSharesOutstanding": {
     "auth_ref": [
      "r25",
      "r185"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.",
        "label": "Common Stock, Shares, Outstanding",
        "periodEndLabel": "Balance (in shares)",
        "periodStartLabel": "Balance (in shares)",
        "terseLabel": "Common stock, shares outstanding"
       }
      }
     },
     "localname": "CommonStockSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockValue": {
     "auth_ref": [
      "r25"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.",
        "label": "Common Stock, Value, Issued",
        "terseLabel": "Common stock ($1.50 par, 480,000,000 shares authorized and 183,852,855 and 186,975,693 shares issued and outstanding as of June 30, 2020, and December 31, 2019, respectively)"
       }
      }
     },
     "localname": "CommonStockValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CompensationAndRetirementDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Retirement Benefit Plans"
       }
      }
     },
     "localname": "CompensationAndRetirementDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_ComprehensiveIncomeNetOfTax": {
     "auth_ref": [
      "r61",
      "r63",
      "r64"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "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) attributable to JHG"
       }
      }
     },
     "localname": "ComprehensiveIncomeNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ComprehensiveIncomeNetOfTaxAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Accumulated Other Comprehensive Loss"
       }
      }
     },
     "localname": "ComprehensiveIncomeNetOfTaxAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest": {
     "auth_ref": [
      "r61",
      "r63",
      "r256",
      "r257",
      "r272"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 2.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income (loss) and other comprehensive income (loss), attributable to noncontrolling interests. Excludes changes in equity resulting from investments by owners and distributions to owners.",
        "label": "Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest",
        "negatedLabel": "Total comprehensive loss (income) attributable to noncontrolling interests"
       }
      }
     },
     "localname": "ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest": {
     "auth_ref": [
      "r61",
      "r63",
      "r255",
      "r272"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 1.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax",
       "weight": 1.0
      }
     },
     "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. Excludes changes in equity resulting from investments by owners and distributions to owners.",
        "label": "Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest",
        "terseLabel": "Total comprehensive income (loss)"
       }
      }
     },
     "localname": "ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterestAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Other Comprehensive Income (Loss), Net of Tax [Abstract]",
        "terseLabel": "Other comprehensive income (loss), net of tax:"
       }
      }
     },
     "localname": "ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterestAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ComprehensiveIncomeNoteTextBlock": {
     "auth_ref": [
      "r75"
     ],
     "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 Loss"
       }
      }
     },
     "localname": "ComprehensiveIncomeNoteTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLoss"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ConsolidatedEntitiesMember": {
     "auth_ref": [
      "r327",
      "r329",
      "r331",
      "r333",
      "r335",
      "r337"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Entities which have been consolidated for financial statement presentation purposes.",
        "label": "Consolidated Entities [Member]",
        "terseLabel": "Consolidated"
       }
      }
     },
     "localname": "ConsolidatedEntitiesMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails",
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CostsAndExpenses": {
     "auth_ref": [
      "r70"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 2.0,
       "parentTag": "us-gaap_OperatingIncomeLoss",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Total costs of sales and operating expenses for the period.",
        "label": "Costs and Expenses",
        "totalLabel": "Total operating expenses"
       }
      }
     },
     "localname": "CostsAndExpenses",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CostsAndExpensesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Costs and Expenses [Abstract]",
        "terseLabel": "Operating expenses:"
       }
      }
     },
     "localname": "CostsAndExpensesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CreditDefaultSwapMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A type of swap transaction used as a credit derivative in which one party makes periodic payments to the other and receives the promise of a pay-off if a third party defaults.",
        "label": "Credit Default Swap [Member]",
        "terseLabel": "Credit default swaps"
       }
      }
     },
     "localname": "CreditDefaultSwapMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CustomerRelationshipsMember": {
     "auth_ref": [
      "r246"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Customer relationship that exists between an entity and its customer, for example, but not limited to, tenant relationships.",
        "label": "Customer Relationships [Member]",
        "terseLabel": "Client relationships"
       }
      }
     },
     "localname": "CustomerRelationshipsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails",
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsTables"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DebtDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Debt"
       }
      }
     },
     "localname": "DebtDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtDisclosureTextBlock": {
     "auth_ref": [
      "r180"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.",
        "label": "Debt Disclosure [Text Block]",
        "terseLabel": "Debt"
       }
      }
     },
     "localname": "DebtDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebt"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DebtInstrumentAxis": {
     "auth_ref": [
      "r21",
      "r22",
      "r23",
      "r342",
      "r343",
      "r351"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of debt instrument, including, but not limited to, draws against credit facilities.",
        "label": "Debt Instrument [Axis]"
       }
      }
     },
     "localname": "DebtInstrumentAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtInstrumentFaceAmount": {
     "auth_ref": [
      "r313",
      "r315"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Face (par) amount of debt instrument at time of issuance.",
        "label": "Debt Instrument, Face Amount",
        "terseLabel": "Face value of debt issued"
       }
      }
     },
     "localname": "DebtInstrumentFaceAmount",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtInstrumentInterestRateStatedPercentage": {
     "auth_ref": [
      "r38"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Contractual interest rate for funds borrowed, under the debt agreement.",
        "label": "Debt Instrument, Interest Rate, Stated Percentage",
        "terseLabel": "Interest rate (as a percent)"
       }
      }
     },
     "localname": "DebtInstrumentInterestRateStatedPercentage",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "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"
       }
      }
     },
     "localname": "DebtInstrumentLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtInstrumentNameDomain": {
     "auth_ref": [
      "r39"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The name for the particular debt instrument or borrowing that distinguishes it from other debt instruments or borrowings, including draws against credit facilities.",
        "label": "Debt Instrument Name [Domain]",
        "terseLabel": "Debt Instrument, Name [Domain]"
       }
      }
     },
     "localname": "DebtInstrumentNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DebtInstrumentTable": {
     "auth_ref": [
      "r39",
      "r94",
      "r186",
      "r187",
      "r188",
      "r189",
      "r312",
      "r313",
      "r315",
      "r350"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtInstrumentUnamortizedPremium": {
     "auth_ref": [
      "r312",
      "r315"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, after accumulated amortization, of debt premium.",
        "label": "Debt Instrument, Unamortized Premium",
        "terseLabel": "Unamortized premium, net"
       }
      }
     },
     "localname": "DebtInstrumentUnamortizedPremium",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesTradingUnrealizedGainLoss": {
     "auth_ref": [
      "r130"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in net income (trading).",
        "label": "Debt Securities, Trading, Unrealized Gain (Loss)",
        "terseLabel": "Unrealized gains on investment securities held at period end"
       }
      }
     },
     "localname": "DebtSecuritiesTradingUnrealizedGainLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible": {
     "auth_ref": [
      "r228"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of decrease reasonably possible in the next twelve months for the unrecognized tax benefit.",
        "label": "Significant (Increase) Decrease in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound",
        "terseLabel": "Anticipated decrease in income tax contingency reserves in the next 12 months"
       }
      }
     },
     "localname": "DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredBonusMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "An contractual arrangement whereby an employee is entitled to receive in the future, subject to vesting and other restrictions, a bonus, as defined in the agreement, of the entity or portion thereof. Employer contributions may be discretionary or may be based on a fixed formula related to individual, group and entity-wide performance goals, compensation, or other factors. It is a form of incentive compensation to employees in addition to their regular salary and profit sharing.",
        "label": "Deferred Bonus [Member]",
        "terseLabel": "Deferred bonuses"
       }
      }
     },
     "localname": "DeferredBonusMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DeferredIncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r88",
      "r93",
      "r234",
      "r238"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.",
        "label": "Deferred Income Tax Expense (Benefit)",
        "terseLabel": "Deferred income taxes"
       }
      }
     },
     "localname": "DeferredIncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredIncomeTaxLiabilitiesNet": {
     "auth_ref": [
      "r225",
      "r233"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences with jurisdictional netting.",
        "label": "Deferred Tax Liabilities, Net, Noncurrent",
        "terseLabel": "Deferred tax liabilities, net"
       }
      }
     },
     "localname": "DeferredIncomeTaxLiabilitiesNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit": {
     "auth_ref": [
      "r206",
      "r212",
      "r213"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureRetirementBenefitPlansActuarialGainsLossesBenefitCostCashFlowsDetails": {
       "order": 4.0,
       "parentTag": "jhg_DefinedBenefitPlanPeriodicBenefitCostCreditBeforeContributionToMoneyPurchaseSection",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan.",
        "label": "Defined Benefit Plan, Amortization of Prior Service Cost (Credit)",
        "negatedLabel": "Amortization of prior service cost"
       }
      }
     },
     "localname": "DefinedBenefitPlanAmortizationOfPriorServiceCostCredit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureRetirementBenefitPlansActuarialGainsLossesBenefitCostCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets": {
     "auth_ref": [
      "r205",
      "r211",
      "r213"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureRetirementBenefitPlansActuarialGainsLossesBenefitCostCashFlowsDetails": {
       "order": 3.0,
       "parentTag": "jhg_DefinedBenefitPlanPeriodicBenefitCostCreditBeforeContributionToMoneyPurchaseSection",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan.",
        "label": "Defined Benefit Plan, Expected Return on Plan Assets",
        "terseLabel": "Expected return on plan assets"
       }
      }
     },
     "localname": "DefinedBenefitPlanExpectedReturnOnPlanAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureRetirementBenefitPlansActuarialGainsLossesBenefitCostCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanInterestCost": {
     "auth_ref": [
      "r199",
      "r204",
      "r210",
      "r213"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureRetirementBenefitPlansActuarialGainsLossesBenefitCostCashFlowsDetails": {
       "order": 2.0,
       "parentTag": "jhg_DefinedBenefitPlanPeriodicBenefitCostCreditBeforeContributionToMoneyPurchaseSection",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cost recognized for passage of time related to defined benefit plan.",
        "label": "Defined Benefit Plan, Interest Cost",
        "negatedLabel": "Interest cost"
       }
      }
     },
     "localname": "DefinedBenefitPlanInterestCost",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureRetirementBenefitPlansActuarialGainsLossesBenefitCostCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]",
        "terseLabel": "Components of net periodic benefit cost"
       }
      }
     },
     "localname": "DefinedBenefitPlanNetPeriodicBenefitCostAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureRetirementBenefitPlansActuarialGainsLossesBenefitCostCashFlowsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DefinedBenefitPlanServiceCost": {
     "auth_ref": [
      "r198",
      "r203",
      "r209",
      "r213"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureRetirementBenefitPlansActuarialGainsLossesBenefitCostCashFlowsDetails": {
       "order": 1.0,
       "parentTag": "jhg_DefinedBenefitPlanPeriodicBenefitCostCreditBeforeContributionToMoneyPurchaseSection",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.",
        "label": "Defined Benefit Plan, Service Cost",
        "negatedLabel": "Service cost"
       }
      }
     },
     "localname": "DefinedBenefitPlanServiceCost",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureRetirementBenefitPlansActuarialGainsLossesBenefitCostCashFlowsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DepreciationDepletionAndAmortization": {
     "auth_ref": [
      "r88",
      "r122"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.",
        "label": "Depreciation, Depletion and Amortization",
        "terseLabel": "Depreciation and amortization"
       }
      }
     },
     "localname": "DepreciationDepletionAndAmortization",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeAssets": {
     "auth_ref": [
      "r47",
      "r48",
      "r299"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_AssetsFairValueDisclosure",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.",
        "label": "Derivative Asset",
        "verboseLabel": "Derivative assets"
       }
      }
     },
     "localname": "DerivativeAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeContractTypeDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Financial instrument or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.",
        "label": "Derivative Contract Type [Domain]",
        "terseLabel": "Derivative Contract [Domain]"
       }
      }
     },
     "localname": "DerivativeContractTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DerivativeInstrumentRiskAxis": {
     "auth_ref": [
      "r278",
      "r279",
      "r280",
      "r283"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of derivative contract.",
        "label": "Derivative Instrument [Axis]"
       }
      }
     },
     "localname": "DerivativeInstrumentRiskAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DerivativeLiabilities": {
     "auth_ref": [
      "r47",
      "r48",
      "r299"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_LiabilitiesFairValueDisclosure",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.",
        "label": "Derivative Liability",
        "terseLabel": "Derivative liabilities"
       }
      }
     },
     "localname": "DerivativeLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeNotionalAmount": {
     "auth_ref": [
      "r275",
      "r276"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Nominal or face amount used to calculate payment on derivative.",
        "label": "Derivative, Notional Amount",
        "terseLabel": "Notional value of derivative",
        "verboseLabel": "Notional value of derivative"
       }
      }
     },
     "localname": "DerivativeNotionalAmount",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock": {
     "auth_ref": [
      "r223"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for share-based payment arrangement.",
        "label": "Disclosure of Compensation Related Costs, Share-based Payments [Text Block]",
        "terseLabel": "Long-Term Incentive Compensation"
       }
      }
     },
     "localname": "DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureLongTermIncentiveCompensation"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Long-Term Incentive Compensation"
       }
      }
     },
     "localname": "DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_DiscontinuedOperationsAndDisposalGroupsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Dispositions",
        "terseLabel": "Sale"
       }
      }
     },
     "localname": "DiscontinuedOperationsAndDisposalGroupsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DiscontinuedOperationsDisposedOfBySaleMember": {
     "auth_ref": [
      "r2"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Component or group of components disposed of by sale and representing a strategic shift that has or will have a major effect on operations and financial results.",
        "label": "Discontinued Operations Disposed Of By Sale [Member]",
        "terseLabel": "Discontinued Operations, Disposed of by Sale"
       }
      }
     },
     "localname": "DiscontinuedOperationsDisposedOfBySaleMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DisposalGroupClassificationAxis": {
     "auth_ref": [
      "r11"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by disposal group classification.",
        "label": "Disposal Group Classification [Axis]"
       }
      }
     },
     "localname": "DisposalGroupClassificationAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DisposalGroupClassificationDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Component or group of components disposed of, including but not limited to, disposal group held-for-sale or disposed of by sale, disposed of by means other than sale, and discontinued operations.",
        "label": "Disposal Group Classification [Domain]",
        "terseLabel": "Disposal Group Classification [Domain]"
       }
      }
     },
     "localname": "DisposalGroupClassificationDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.",
        "label": "Disposal Group, Including Discontinued Operation, Consideration",
        "terseLabel": "Consideration received",
        "verboseLabel": "Cash"
       }
      }
     },
     "localname": "DisposalGroupIncludingDiscontinuedOperationConsideration",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsDetails",
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DisposalGroupIncludingDiscontinuedOperationGoodwill1": {
     "auth_ref": [
      "r0",
      "r1",
      "r9",
      "r171"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount classified as goodwill attributable to disposal group held for sale or disposed of.",
        "label": "Disposal Group, Including Discontinued Operation, Goodwill",
        "negatedLabel": "Disposal",
        "terseLabel": "Less: Goodwill allocation",
        "verboseLabel": "Allocated goodwill"
       }
      }
     },
     "localname": "DisposalGroupIncludingDiscontinuedOperationGoodwill1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails",
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DisposalGroupIncludingDiscontinuedOperationIntangibleAssets": {
     "auth_ref": [
      "r0",
      "r1",
      "r9",
      "r171"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount classified as intangible assets, excluding goodwill, attributable to disposal group held for sale or disposed of.",
        "label": "Disposal Group, Including Discontinued Operation, Intangible Assets",
        "terseLabel": "Disposal",
        "verboseLabel": "Intangible assets"
       }
      }
     },
     "localname": "DisposalGroupIncludingDiscontinuedOperationIntangibleAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails",
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherAssets": {
     "auth_ref": [
      "r0",
      "r1",
      "r9",
      "r171"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount classified as other assets attributable to disposal group held for sale or disposed of.",
        "label": "Disposal Group, Including Discontinued Operation, Other Assets",
        "terseLabel": "Other assets"
       }
      }
     },
     "localname": "DisposalGroupIncludingDiscontinuedOperationOtherAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherLiabilities": {
     "auth_ref": [
      "r0",
      "r1",
      "r9",
      "r171"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount classified as other liabilities attributable to disposal group held for sale or disposed of.",
        "label": "Disposal Group, Including Discontinued Operation, Other Liabilities",
        "negatedLabel": "Other liabilities"
       }
      }
     },
     "localname": "DisposalGroupIncludingDiscontinuedOperationOtherLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DisposalGroupIncludingDiscontinuedOperationUnclassifiedBalanceSheetDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Disposal Group, Including Discontinued Operation, Unclassified Balance Sheet Disclosures [Abstract]",
        "terseLabel": "Less carrying amount of assets and liabilities:"
       }
      }
     },
     "localname": "DisposalGroupIncludingDiscontinuedOperationUnclassifiedBalanceSheetDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DisposalGroupNotDiscontinuedOperationDisposalDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Disposal Group, Not Discontinued Operation, Disposal Disclosures [Abstract]",
        "terseLabel": "Consideration received"
       }
      }
     },
     "localname": "DisposalGroupNotDiscontinuedOperationDisposalDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal": {
     "auth_ref": [
      "r88",
      "r168",
      "r170"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.",
        "label": "Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal",
        "negatedLabel": "Gain on sale of Geneva",
        "terseLabel": "Net gain on sale, before taxes",
        "verboseLabel": "Gain on the sale of Geneva"
       }
      }
     },
     "localname": "DisposalGroupNotDiscontinuedOperationGainLossOnDisposal",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsDetails",
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock": {
     "auth_ref": [
      "r15",
      "r174"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component.",
        "label": "Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]",
        "terseLabel": "Dispositions"
       }
      }
     },
     "localname": "DisposalGroupsIncludingDiscontinuedOperationsDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositions"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Name of disposal group.",
        "label": "Disposal Groups Including Discontinued Operations Name [Domain]",
        "terseLabel": "Disposal Group Name [Domain]"
       }
      }
     },
     "localname": "DisposalGroupsIncludingDiscontinuedOperationsNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsDetails",
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DividendsCashAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Dividends, Cash [Abstract]",
        "terseLabel": "Dividends Per Share"
       }
      }
     },
     "localname": "DividendsCashAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DividendsCommonStockCash": {
     "auth_ref": [
      "r190"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.",
        "label": "Dividends, Common Stock, Cash",
        "negatedLabel": "Dividends paid to shareholders"
       }
      }
     },
     "localname": "DividendsCommonStockCash",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DividendsDeclaredTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of information related to dividends declared, including paid and unpaid dividends.",
        "label": "Dividends Declared [Table Text Block]",
        "terseLabel": "Schedule of cash dividends declared and paid"
       }
      }
     },
     "localname": "DividendsDeclaredTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_EarningsPerShareBasic": {
     "auth_ref": [
      "r68",
      "r99",
      "r107",
      "r112",
      "r116",
      "r117",
      "r120",
      "r348",
      "r359"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.",
        "label": "Earnings Per Share, Basic",
        "terseLabel": "Basic (in dollars per share)",
        "verboseLabel": "Basic (two class) (in dollars per share)"
       }
      }
     },
     "localname": "EarningsPerShareBasic",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_EarningsPerShareBasicAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Earnings Per Share, Basic [Abstract]",
        "terseLabel": "Earnings (loss) per share:"
       }
      }
     },
     "localname": "EarningsPerShareBasicAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EarningsPerShareBasicAndDilutedOtherDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Earnings (Loss) and Dividends Per Share",
        "terseLabel": "Earnings (loss) per share attributable to JHG common shareholders:"
       }
      }
     },
     "localname": "EarningsPerShareBasicAndDilutedOtherDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EarningsPerShareBasicOtherDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Earnings Per Share, Basic, Other Disclosures [Abstract]",
        "terseLabel": "Earnings (loss) per share"
       }
      }
     },
     "localname": "EarningsPerShareBasicOtherDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EarningsPerShareDiluted": {
     "auth_ref": [
      "r68",
      "r99",
      "r107",
      "r112",
      "r116",
      "r117",
      "r120",
      "r348",
      "r359"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.",
        "label": "Earnings Per Share, Diluted",
        "terseLabel": "Diluted (in dollars per share)",
        "verboseLabel": "Diluted (two class) (in dollars per share)"
       }
      }
     },
     "localname": "EarningsPerShareDiluted",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations": {
     "auth_ref": [
      "r306"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease) from effect of exchange rate changes on cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage; held in foreign currencies; including, but not limited to, 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": "Effects Of Exchange Rate On Cash And Cash Equivalents",
        "terseLabel": "Effect of foreign exchange rate changes"
       }
      }
     },
     "localname": "EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EffectiveIncomeTaxRateContinuingOperations": {
     "auth_ref": [
      "r95",
      "r226",
      "r227"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.",
        "label": "Effective Income Tax Rate Reconciliation, Percent",
        "verboseLabel": "Effective tax rate (as a percent)"
       }
      }
     },
     "localname": "EffectiveIncomeTaxRateContinuingOperations",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate": {
     "auth_ref": [
      "r226",
      "r227",
      "r237"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage of domestic federal statutory tax rate applicable to pretax income (loss).",
        "label": "Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent",
        "verboseLabel": "Statutory corporation tax rate (as a percentage)"
       }
      }
     },
     "localname": "EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_EmployeeRelatedLiabilitiesCurrent": {
     "auth_ref": [
      "r36"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
        "label": "Employee-related Liabilities, Current",
        "terseLabel": "Current portion of accrued compensation, benefits and staff costs"
       }
      }
     },
     "localname": "EmployeeRelatedLiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems": {
     "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, Compensation Cost [Line Items]",
        "verboseLabel": "Long-Term Incentive and Employee Compensation"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureLongTermIncentiveAndEmployeeCompensationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EquityComponentDomain": {
     "auth_ref": [
      "r185"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Components of equity are the parts of the total Equity balance including that which is allocated to common, preferred, treasury stock, retained earnings, etc.",
        "label": "Equity Component [Domain]",
        "terseLabel": "Equity Component [Domain]"
       }
      }
     },
     "localname": "EquityComponentDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails",
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossOciDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EquityMethodInvesteeMember": {
     "auth_ref": [
      "r133",
      "r328",
      "r330",
      "r332",
      "r334",
      "r336",
      "r338"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "An entity that issued voting stock held by an investor and that is accounted for under the equity method of accounting by the investor.",
        "label": "Equity Method Investee [Member]",
        "terseLabel": "Unconsolidated VIEs and VREs"
       }
      }
     },
     "localname": "EquityMethodInvesteeMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EstimateOfFairValueFairValueDisclosureMember": {
     "auth_ref": [
      "r299"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Measured as an estimate of fair value.",
        "label": "Estimate Of Fair Value Fair Value Disclosure [Member]",
        "terseLabel": "Fair value"
       }
      }
     },
     "localname": "EstimateOfFairValueFairValueDisclosureMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "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]",
        "terseLabel": "Assets and liabilities carried at fair value"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable": {
     "auth_ref": [
      "r285",
      "r286",
      "r287",
      "r295"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about asset and liability measured at fair value on recurring and nonrecurring basis.",
        "label": "Fair Value Measurements, Recurring and Nonrecurring [Table]"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock": {
     "auth_ref": [
      "r288"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of input and valuation technique used to measure fair value and change in valuation approach and technique for each separate class of asset and liability measured on recurring and nonrecurring basis.",
        "label": "Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Table Text Block]",
        "verboseLabel": "Summary of valuation techniques and significant unobservable inputs used in the valuation of the company's private equity investments"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain": {
     "auth_ref": [
      "r291"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Class of asset.",
        "label": "Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation By Asset Class [Domain]",
        "terseLabel": "Asset Class [Domain]"
       }
      }
     },
     "localname": "FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]",
        "terseLabel": "Change in fair value of Level 3 assets"
       }
      }
     },
     "localname": "FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByAssetClassAxis": {
     "auth_ref": [
      "r285",
      "r295"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by class of asset.",
        "label": "Asset Class [Axis]"
       }
      }
     },
     "localname": "FairValueByAssetClassAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByFairValueHierarchyLevelAxis": {
     "auth_ref": [
      "r200",
      "r201",
      "r213",
      "r286",
      "r321"
     ],
     "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 [Axis]"
       }
      }
     },
     "localname": "FairValueByFairValueHierarchyLevelAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByMeasurementBasisAxis": {
     "auth_ref": [
      "r285",
      "r296"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by measurement basis.",
        "label": "Measurement Basis [Axis]"
       }
      }
     },
     "localname": "FairValueByMeasurementBasisAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByMeasurementFrequencyAxis": {
     "auth_ref": [
      "r285",
      "r286",
      "r289",
      "r290",
      "r297"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by measurement frequency.",
        "label": "Measurement Frequency [Axis]"
       }
      }
     },
     "localname": "FairValueByMeasurementFrequencyAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Fair Value Measurements"
       }
      }
     },
     "localname": "FairValueDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueDisclosuresTextBlock": {
     "auth_ref": [
      "r293"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurements"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueInputsLevel1Member": {
     "auth_ref": [
      "r200",
      "r201",
      "r213",
      "r286",
      "r322"
     ],
     "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 Level1 [Member]",
        "terseLabel": "Level 1"
       }
      }
     },
     "localname": "FairValueInputsLevel1Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueInputsLevel2Member": {
     "auth_ref": [
      "r200",
      "r201",
      "r213",
      "r286",
      "r323"
     ],
     "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 Level2 [Member]",
        "terseLabel": "Level 2"
       }
      }
     },
     "localname": "FairValueInputsLevel2Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueInputsLevel3Member": {
     "auth_ref": [
      "r200",
      "r201",
      "r213",
      "r286",
      "r324"
     ],
     "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 Level3 [Member]",
        "terseLabel": "Level 3"
       }
      }
     },
     "localname": "FairValueInputsLevel3Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementFrequencyDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Measurement frequency.",
        "label": "Fair Value Measurement Frequency [Domain]",
        "terseLabel": "Fair Value, Measurement Frequency [Domain]"
       }
      }
     },
     "localname": "FairValueMeasurementFrequencyDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements": {
     "auth_ref": [
      "r292"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements",
        "negatedLabel": "Settlements"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue": {
     "auth_ref": [
      "r291"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value",
        "periodEndLabel": "Balance at the end of period, Asset value",
        "periodStartLabel": "Balance at the beginning of period, Asset value"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue": {
     "auth_ref": [
      "r291"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value",
        "periodEndLabel": "Balance at the end of period, Liability Value",
        "periodStartLabel": "Balance at the beginning of period, Liability Value"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueMeasurementsFairValueHierarchyDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Categories used to prioritize the inputs to valuation techniques to measure fair value.",
        "label": "Fair Value Measurements Fair Value Hierarchy [Domain]",
        "terseLabel": "Fair Value Hierarchy [Domain]"
       }
      }
     },
     "localname": "FairValueMeasurementsFairValueHierarchyDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementsRecurringMember": {
     "auth_ref": [
      "r293",
      "r297"
     ],
     "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 Measurements Recurring [Member]",
        "terseLabel": "Fair value measurements, recurring"
       }
      }
     },
     "localname": "FairValueMeasurementsRecurringMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTable": {
     "auth_ref": [
      "r291",
      "r294"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset) using recurring unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table]"
       }
      }
     },
     "localname": "FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinanceLeasePrincipalPayments": {
     "auth_ref": [
      "r316",
      "r317"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash outflow for principal payment on finance lease.",
        "label": "Finance Lease, Principal Payments",
        "negatedLabel": "Principal payments under capital lease obligations"
       }
      }
     },
     "localname": "FinanceLeasePrincipalPayments",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancialInstrumentAxis": {
     "auth_ref": [
      "r136",
      "r137",
      "r138",
      "r139",
      "r140",
      "r141",
      "r142",
      "r143",
      "r144"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of financial instrument.",
        "label": "Financial Instrument [Axis]"
       }
      }
     },
     "localname": "FinancialInstrumentAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]",
        "terseLabel": "Liabilities"
       }
      }
     },
     "localname": "FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancialInstrumentsSoldNotYetPurchasedDerivativesAndOtherContracts": {
     "auth_ref": [
      "r340"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fair value of obligations arising from derivatives and other contracts sold short.",
        "label": "Financial Instruments Sold, Not yet Purchased, Derivatives and Other Contracts",
        "terseLabel": "Securities sold, not yet purchased"
       }
      }
     },
     "localname": "FinancialInstrumentsSoldNotYetPurchasedDerivativesAndOtherContracts",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization": {
     "auth_ref": [
      "r159"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.",
        "label": "Finite-Lived Intangible Assets, Accumulated Amortization",
        "negatedPeriodEndLabel": "Accumulated amortization, balance at the end of the period",
        "negatedPeriodStartLabel": "Accumulated amortization, balance at the beginning of the period"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAccumulatedAmortization",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_FiniteLivedIntangibleAssetsNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, after Year Five",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths": {
     "auth_ref": [
      "r161"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_FiniteLivedIntangibleAssetsNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months",
        "terseLabel": "2020 (remainder of year)"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive": {
     "auth_ref": [
      "r161"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_FiniteLivedIntangibleAssetsNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Year Five",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseYearFive",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour": {
     "auth_ref": [
      "r161"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_FiniteLivedIntangibleAssetsNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Year Four",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseYearFour",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree": {
     "auth_ref": [
      "r161"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_FiniteLivedIntangibleAssetsNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Year Three",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseYearThree",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo": {
     "auth_ref": [
      "r161"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_FiniteLivedIntangibleAssetsNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Year Two",
        "terseLabel": "2021"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis": {
     "auth_ref": [
      "r154",
      "r156",
      "r159",
      "r163",
      "r326"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by major type or class of finite-lived intangible assets.",
        "label": "Finite-Lived Intangible Assets by Major Class [Axis]"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsByMajorClassAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails",
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsTables"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of foreign currency translation gain (loss) which increases (decreases) assets, excluding financial assets and goodwill, lacking physical substance with a finite life.",
        "label": "Foreign currency translation",
        "negatedLabel": "Foreign currency translation"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]",
        "terseLabel": "Future Amortization:"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsGross": {
     "auth_ref": [
      "r159",
      "r326"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.",
        "label": "Finite-Lived Intangible Assets, Gross",
        "periodEndLabel": "Balance at the end of the period",
        "periodStartLabel": "Balance at the beginning of the period"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsGross",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsLineItems": {
     "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": "Finite-Lived Intangible Assets [Line Items]",
        "terseLabel": "Goodwill and Intangible Assets"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsTables"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain": {
     "auth_ref": [
      "r154",
      "r158"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The major class of finite-lived intangible asset (for example, patents, trademarks, copyrights, etc.) A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.",
        "label": "Finite Lived Intangible Assets Major Class Name [Domain]",
        "terseLabel": "Finite-Lived Intangible Assets, Major Class Name [Domain]"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsMajorClassNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails",
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsTables"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsNet": {
     "auth_ref": [
      "r159"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.",
        "label": "Finite-Lived Intangible Assets, Net",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Finite-lived Intangible Assets [Roll Forward]",
        "terseLabel": "Definite-lived intangible assets:"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ForeignCurrencyTransactionGainLossRealized": {
     "auth_ref": [
      "r303",
      "r304",
      "r305"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails": {
       "order": 1.0,
       "parentTag": "jhg_GainsLossesOnDerivativeInstrumentsHeldForTradingPurposesNetDenominatedInForeignCurrency",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before tax of foreign currency transaction realized gain (loss) recognized in the income statement.",
        "label": "Foreign Currency Transaction Gain (Loss), Realized",
        "terseLabel": "Foreign currency translation"
       }
      }
     },
     "localname": "ForeignCurrencyTransactionGainLossRealized",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ForeignExchangeForwardMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Foreign exchange forward traded on an exchange (examples include but are not limited to the International Securities Exchange, Philadelphia Stock Exchange, or the Chicago Mercantile Exchange) for options or future contracts to buy or sell a certain currency, at a specified date, at a fixed exercise exchange rate.",
        "label": "Foreign Exchange Forward [Member]",
        "terseLabel": "Foreign currency forward contracts"
       }
      }
     },
     "localname": "ForeignExchangeForwardMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FutureMember": {
     "auth_ref": [
      "r281"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Futures contracts are forward-based contracts to make or take delivery of a specified financial instrument, foreign currency, or commodity at a specified future date or during a specified period at as specified price or yield. Futures are standardized contracts traded on an organized exchange.",
        "label": "Future [Member]",
        "terseLabel": "Futures"
       }
      }
     },
     "localname": "FutureMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_GainLossOnInvestments": {
     "auth_ref": [
      "r73",
      "r88",
      "r129"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 3.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
       "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": "Investment gains (losses), net"
       }
      }
     },
     "localname": "GainLossOnInvestments",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GainLossOnInvestmentsTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of realized and unrealized gain (loss) on investment in security.",
        "label": "Gain (Loss) on Investments [Table Text Block]",
        "verboseLabel": "Schedule of investment gains (losses), net in Consolidated Statements of Comprehensive Income"
       }
      }
     },
     "localname": "GainLossOnInvestmentsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_GeneralAndAdministrativeExpense": {
     "auth_ref": [
      "r72"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 8.0,
       "parentTag": "us-gaap_CostsAndExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.",
        "label": "General, Administrative and Occupancy",
        "terseLabel": "General, administrative and occupancy"
       }
      }
     },
     "localname": "GeneralAndAdministrativeExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_Goodwill": {
     "auth_ref": [
      "r145",
      "r147"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.",
        "label": "Goodwill",
        "periodEndLabel": "Goodwill, balance at the end of the period",
        "periodStartLabel": "Goodwill, balance at the beginning of the period",
        "terseLabel": "Goodwill"
       }
      }
     },
     "localname": "Goodwill",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GoodwillAndIntangibleAssetImpairment": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      },
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 7.0,
       "parentTag": "us-gaap_CostsAndExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Total loss recognized during the period from the impairment of goodwill plus the loss recognized in the period resulting from the impairment of the carrying amount of intangible assets, other than goodwill.",
        "label": "Goodwill and Intangible Asset Impairment",
        "terseLabel": "Goodwill and intangible assets impairment",
        "verboseLabel": "Impairment of goodwill and intangible assets"
       }
      }
     },
     "localname": "GoodwillAndIntangibleAssetImpairment",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Goodwill and Intangible Assets"
       }
      }
     },
     "localname": "GoodwillAndIntangibleAssetsDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock": {
     "auth_ref": [
      "r167"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for goodwill and intangible assets.",
        "label": "Goodwill and Intangible Assets Disclosure [Text Block]",
        "terseLabel": "Goodwill and Intangible Assets"
       }
      }
     },
     "localname": "GoodwillAndIntangibleAssetsDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssets"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_GoodwillForeignCurrencyTranslationGainLoss": {
     "auth_ref": [
      "r149"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.",
        "label": "Goodwill, Translation Adjustments",
        "negatedLabel": "Foreign currency translation"
       }
      }
     },
     "localname": "GoodwillForeignCurrencyTranslationGainLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GoodwillImpairmentLoss": {
     "auth_ref": [
      "r88",
      "r146",
      "r148",
      "r151"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.",
        "label": "Goodwill, Impairment Loss",
        "terseLabel": "Impairment"
       }
      }
     },
     "localname": "GoodwillImpairmentLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GoodwillRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Goodwill [Roll Forward]",
        "terseLabel": "Goodwill"
       }
      }
     },
     "localname": "GoodwillRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_HedgingDesignationAxis": {
     "auth_ref": [
      "r277",
      "r284"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by designation of purpose of derivative instrument.",
        "label": "Hedging Designation [Axis]"
       }
      }
     },
     "localname": "HedgingDesignationAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_HedgingDesignationDomain": {
     "auth_ref": [
      "r277"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Designation of purpose of derivative instrument.",
        "label": "Hedging Designation [Domain]",
        "terseLabel": "Hedging Designation [Domain]"
       }
      }
     },
     "localname": "HedgingDesignationDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill": {
     "auth_ref": [
      "r88",
      "r164"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of an intangible asset (excluding goodwill) to fair value.",
        "label": "Impairment of Intangible Assets (Excluding Goodwill)",
        "negatedLabel": "Impairment"
       }
      }
     },
     "localname": "ImpairmentOfIntangibleAssetsExcludingGoodwill",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairmentOfIntangibleAssetsFinitelived": {
     "auth_ref": [
      "r88",
      "r164"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of a finite-lived intangible asset to fair value.",
        "label": "Impairment of Intangible Assets, Finite-lived",
        "verboseLabel": "Impairment"
       }
      }
     },
     "localname": "ImpairmentOfIntangibleAssetsFinitelived",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill": {
     "auth_ref": [
      "r88",
      "r164"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.",
        "label": "Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)",
        "negatedLabel": "Impairment",
        "terseLabel": "Impairment"
       }
      }
     },
     "localname": "ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest": {
     "auth_ref": [
      "r67",
      "r99",
      "r339",
      "r347",
      "r360"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 1.0,
       "parentTag": "us-gaap_ProfitLoss",
       "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 Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest",
        "totalLabel": "Income (loss) before taxes"
       }
      }
     },
     "localname": "IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeStatementAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)"
       }
      }
     },
     "localname": "IncomeStatementAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by name of disposal group.",
        "label": "Disposal Group Name [Axis]"
       }
      }
     },
     "localname": "IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsDetails",
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]",
        "terseLabel": "Dispositions"
       }
      }
     },
     "localname": "IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsDetails",
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable": {
     "auth_ref": [
      "r1",
      "r3",
      "r4",
      "r5",
      "r6",
      "r7",
      "r8",
      "r10",
      "r12",
      "r13",
      "r14",
      "r172",
      "r173"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component.",
        "label": "Disposal Groups, Including Discontinued Operations [Table]"
       }
      }
     },
     "localname": "IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsDetails",
      "http://www.janus.com/role/DisclosureDispositionsGainOnSaleDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfGenevaDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsDisposalOfVolantisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxContingencyLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Income Tax Contingency [Line Items]",
        "terseLabel": "Income taxes"
       }
      }
     },
     "localname": "IncomeTaxContingencyLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxContingencyTable": {
     "auth_ref": [
      "r229",
      "r231",
      "r232",
      "r236"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about tax positions taken in the tax returns filed or to be filed for which it is more likely than not that the tax position will not be sustained upon examination by taxing authorities and other income tax contingencies. Includes, but is not limited to, interest and penalties, reconciliation of unrecognized tax benefits, unrecognized tax benefits that would affect the effective tax rate, tax years that remain subject to examination by tax jurisdictions, and information about positions for which it is reasonably possible that amounts unrecognized will significantly change within 12 months.",
        "label": "Income Tax Contingency [Table]"
       }
      }
     },
     "localname": "IncomeTaxContingencyTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Income Taxes"
       }
      }
     },
     "localname": "IncomeTaxDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxDisclosureTextBlock": {
     "auth_ref": [
      "r241"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxes"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_IncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r93",
      "r123",
      "r240"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 2.0,
       "parentTag": "us-gaap_ProfitLoss",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.",
        "label": "Income Tax Expense (Benefit)",
        "negatedLabel": "Income tax benefit (provision)"
       }
      }
     },
     "localname": "IncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAdjustmentOfDeferredTaxAssetLiability": {
     "auth_ref": [
      "r235"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of income tax expense (benefit) from continuing operations attributable to an adjustment 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.",
        "label": "Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability",
        "terseLabel": "Adjustment to deferred tax assets and liabilities"
       }
      }
     },
     "localname": "IncomeTaxExpenseBenefitContinuingOperationsAdjustmentOfDeferredTaxAssetLiability",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxesPaidNet": {
     "auth_ref": [
      "r91"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes.",
        "label": "Income Taxes Paid, Net",
        "terseLabel": "Cash paid for income taxes, net of refunds"
       }
      }
     },
     "localname": "IncomeTaxesPaidNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInOperatingCapitalAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Increase (Decrease) in Operating Capital [Abstract]",
        "terseLabel": "Changes in operating assets and liabilities:"
       }
      }
     },
     "localname": "IncreaseDecreaseInOperatingCapitalAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncreaseDecreaseInOtherAccruedLiabilities": {
     "auth_ref": [
      "r87"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 14.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in other expenses incurred but not yet paid.",
        "label": "Increase (Decrease) in Other Accruals and Liabilities",
        "terseLabel": "Other accruals and liabilities"
       }
      }
     },
     "localname": "IncreaseDecreaseInOtherAccruedLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInOtherOperatingAssets": {
     "auth_ref": [
      "r87"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 12.0,
       "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": "Other assets"
       }
      }
     },
     "localname": "IncreaseDecreaseInOtherOperatingAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInStockholdersEquityRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Increase (Decrease) in Stockholders' Equity [Roll Forward]",
        "terseLabel": "Increase (Decrease) in Stockholders' Equity"
       }
      }
     },
     "localname": "IncreaseDecreaseInStockholdersEquityRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements": {
     "auth_ref": [
      "r108",
      "r119"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding",
       "weight": 1.0
      }
     },
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.",
        "label": "Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements",
        "verboseLabel": "Dilutive effect of non-participating stock-based awards"
       }
      }
     },
     "localname": "IncrementalCommonSharesAttributableToShareBasedPaymentArrangements",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis": {
     "auth_ref": [
      "r155",
      "r162"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type or class of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.",
        "label": "Indefinite-lived Intangible Assets [Axis]"
       }
      }
     },
     "localname": "IndefiniteLivedIntangibleAssetsByMajorClassAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill": {
     "auth_ref": [
      "r162"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.",
        "label": "Indefinite-Lived Intangible Assets (Excluding Goodwill)",
        "periodEndLabel": "Balance at the end of the period",
        "periodStartLabel": "Balance at the beginning of the period",
        "terseLabel": "Indefinite-Lived Intangible Assets"
       }
      }
     },
     "localname": "IndefiniteLivedIntangibleAssetsExcludingGoodwill",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IndefiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of foreign currency translation gain (loss) which increases (decreases) an asset, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.",
        "label": "Indefinite-lived Intangible Assets, Translation Adjustments",
        "negatedLabel": "Foreign currency translation"
       }
      }
     },
     "localname": "IndefiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain": {
     "auth_ref": [
      "r155",
      "r162"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The major class of indefinite-lived intangible asset (for example, trade names, etc. but not all-inclusive), excluding goodwill. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of the company.",
        "label": "Indefinite Lived Intangible Assets Major Class Name [Domain]",
        "terseLabel": "Indefinite-lived Intangible Assets, Major Class Name [Domain]"
       }
      }
     },
     "localname": "IndefiniteLivedIntangibleAssetsMajorClassNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_IndefiniteLivedIntangibleAssetsRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Indefinite-lived Intangible Assets [Roll Forward]",
        "terseLabel": "Indefinite-lived intangible assets:"
       }
      }
     },
     "localname": "IndefiniteLivedIntangibleAssetsRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IntangibleAssetsNetExcludingGoodwill": {
     "auth_ref": [
      "r152",
      "r157"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.",
        "label": "Intangible Assets, Net (Excluding Goodwill)",
        "periodEndLabel": "Net intangible assets, balance at the end of the period",
        "periodStartLabel": "Net intangible assets, balance at the beginning of the period",
        "terseLabel": "Intangible assets, net"
       }
      }
     },
     "localname": "IntangibleAssetsNetExcludingGoodwill",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestExpense": {
     "auth_ref": [
      "r66",
      "r121",
      "r311",
      "r314",
      "r349"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 2.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
       "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",
        "negatedLabel": "Interest expense"
       }
      }
     },
     "localname": "InterestExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestPaidNet": {
     "auth_ref": [
      "r81",
      "r85",
      "r91"
     ],
     "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, Net",
        "terseLabel": "Cash paid for interest"
       }
      }
     },
     "localname": "InterestPaidNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestRateSwapMember": {
     "auth_ref": [
      "r282"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Forward based contracts in which two parties agree to swap periodic payments that are fixed at the outset of the swap contract with variable payments based on a market interest rate (index rate) over a specified period.",
        "label": "Interest Rate Swap [Member]",
        "terseLabel": "Interest rate swaps"
       }
      }
     },
     "localname": "InterestRateSwapMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InvestmentAdviceMember": {
     "auth_ref": [
      "r195"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Investment recommendation and research provided to customer.",
        "label": "Investment Advice [Member]",
        "terseLabel": "Management fees"
       }
      }
     },
     "localname": "InvestmentAdviceMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InvestmentOwnedAtFairValue": {
     "auth_ref": [
      "r364",
      "r367",
      "r373",
      "r375",
      "r376"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Value of the investment at close of period. For schedules of investments that are categorized, the value would be aggregated by category. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities.",
        "label": "Investment Owned, at Fair Value",
        "terseLabel": "Estimated Fair Value"
       }
      }
     },
     "localname": "InvestmentOwnedAtFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InvestmentPerformanceMember": {
     "auth_ref": [
      "r195"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Result achieved from investment. Excludes non-performance related result from asset under management.",
        "label": "Investment Performance [Member]",
        "terseLabel": "Other revenue"
       }
      }
     },
     "localname": "InvestmentPerformanceMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InvestmentSecondaryCategorizationAxis": {
     "auth_ref": [
      "r370",
      "r371",
      "r372",
      "r374"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by second categorization of investments, which may include, but is not limited to industry.",
        "label": "Investment Secondary Categorization [Axis]"
       }
      }
     },
     "localname": "InvestmentSecondaryCategorizationAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables",
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsNonredeemableDetails",
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_InvestmentTableTextBlock": {
     "auth_ref": [
      "r131",
      "r132",
      "r134",
      "r135"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of investment.",
        "label": "Investment [Table Text Block]",
        "terseLabel": "Summary of investment securities"
       }
      }
     },
     "localname": "InvestmentTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_InvestmentsBySecondaryCategorizationDomain": {
     "auth_ref": [
      "r366",
      "r372"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Investments in the \"Investment Holdings [Table]\" and the \"Summary of Investment Holdings [Table]\" are often categorized at two levels. The first categorization is the investment type. The second categorization can vary. The usual secondary categorizations are industry, country or geography.",
        "label": "Investments By Secondary Categorization [Domain]",
        "terseLabel": "Investments by Secondary Categorization [Domain]"
       }
      }
     },
     "localname": "InvestmentsBySecondaryCategorizationDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables",
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsNonredeemableDetails",
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Investment Securities"
       }
      }
     },
     "localname": "InvestmentsDebtAndEquitySecuritiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_LaborAndRelatedExpense": {
     "auth_ref": [
      "r69"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 1.0,
       "parentTag": "us-gaap_CostsAndExpenses",
       "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",
        "terseLabel": "Employee compensation and benefits"
       }
      }
     },
     "localname": "LaborAndRelatedExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_Liabilities": {
     "auth_ref": [
      "r35"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesAndStockholdersEquity": {
     "auth_ref": [
      "r30",
      "r345",
      "r356"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "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, redeemable noncontrolling interests and equity"
       }
      }
     },
     "localname": "LiabilitiesAndStockholdersEquity",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesAndStockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Liabilities and Equity [Abstract]",
        "terseLabel": "LIABILITIES"
       }
      }
     },
     "localname": "LiabilitiesAndStockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LiabilitiesCurrent": {
     "auth_ref": [
      "r37"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer.",
        "label": "Liabilities, Current",
        "totalLabel": "Total current liabilities"
       }
      }
     },
     "localname": "LiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesCurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Liabilities, Current [Abstract]",
        "terseLabel": "Current liabilities:"
       }
      }
     },
     "localname": "LiabilitiesCurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LiabilitiesFairValueDisclosure": {
     "auth_ref": [
      "r285"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fair value of financial and nonfinancial obligations.",
        "label": "Financial and Nonfinancial Liabilities, Fair Value Disclosure",
        "totalLabel": "Total liabilities"
       }
      }
     },
     "localname": "LiabilitiesFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesNoncurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Liabilities, Noncurrent [Abstract]",
        "terseLabel": "Non-current liabilities:"
       }
      }
     },
     "localname": "LiabilitiesNoncurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LineOfCredit": {
     "auth_ref": [
      "r23",
      "r343",
      "r351"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.",
        "label": "Long-term Line of Credit",
        "terseLabel": "Borrowings under the Credit Facility"
       }
      }
     },
     "localname": "LineOfCredit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity": {
     "auth_ref": [
      "r33"
     ],
     "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": "Credit facility, maximum borrowing capacity"
       }
      }
     },
     "localname": "LineOfCreditFacilityMaximumBorrowingCapacity",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebt": {
     "auth_ref": [
      "r23",
      "r179",
      "r343",
      "r353"
     ],
     "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": "Total debt"
       }
      }
     },
     "localname": "LongTermDebt",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtByCurrentAndNoncurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Long-term Debt, by Current and Noncurrent [Abstract]",
        "terseLabel": "Components of debt"
       }
      }
     },
     "localname": "LongTermDebtByCurrentAndNoncurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LongTermDebtFairValue": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_LiabilitiesFairValueDisclosure",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.",
        "label": "Long-term Debt, Fair Value",
        "terseLabel": "Long-term debt"
       }
      }
     },
     "localname": "LongTermDebtFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtNoncurrent": {
     "auth_ref": [
      "r39"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.",
        "label": "Long-term Debt, Excluding Current Maturities",
        "terseLabel": "Long-term debt"
       }
      }
     },
     "localname": "LongTermDebtNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtOtherDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Long-term Debt, Other Disclosures [Abstract]",
        "terseLabel": "Other Disclosures"
       }
      }
     },
     "localname": "LongTermDebtOtherDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_MarketingExpense": {
     "auth_ref": [
      "r72"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 4.0,
       "parentTag": "us-gaap_CostsAndExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Expenditures for planning and executing the conception, pricing, promotion, and distribution of ideas, goods, and services. Costs of public relations and corporate promotions are typically considered to be marketing costs.",
        "label": "Marketing Expense",
        "terseLabel": "Marketing"
       }
      }
     },
     "localname": "MarketingExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_MeasurementInputDiscountRateMember": {
     "auth_ref": [
      "r288"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Measurement input using interest rate to determine present value of future cash flows.",
        "label": "Measurement Input Discount Rate [Member]",
        "terseLabel": "Discount Rate"
       }
      }
     },
     "localname": "MeasurementInputDiscountRateMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_MeasurementInputEbitdaMultipleMember": {
     "auth_ref": [
      "r288"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Measurement input using earnings before interest, tax, depreciation and amortization (EBITDA) multiple.",
        "label": "Measurement Input Ebitda Multiple [Member]",
        "terseLabel": "EBITDA Multiple"
       }
      }
     },
     "localname": "MeasurementInputEbitdaMultipleMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_MeasurementInputRevenueMultipleMember": {
     "auth_ref": [
      "r288"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Measurement input using market valuation of entity divided by revenue.",
        "label": "Measurement Input Revenue Multiple [Member]",
        "terseLabel": "Price-earnings ratio"
       }
      }
     },
     "localname": "MeasurementInputRevenueMultipleMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_MeasurementInputTypeAxis": {
     "auth_ref": [
      "r288"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of measurement input used to determine value of asset and liability.",
        "label": "Measurement Input Type [Axis]"
       }
      }
     },
     "localname": "MeasurementInputTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_MeasurementInputTypeDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Measurement input used to determine value of asset and liability.",
        "label": "Measurement Input Type [Domain]",
        "terseLabel": "Measurement Input Type [Domain]"
       }
      }
     },
     "localname": "MeasurementInputTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_MinorityInterest": {
     "auth_ref": [
      "r44",
      "r344",
      "r355"
     ],
     "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 is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (that is, noncontrolling interest, previously referred to as minority interest).",
        "label": "Stockholders' Equity Attributable to Noncontrolling Interest",
        "verboseLabel": "Total nonredeemable noncontrolling interests"
       }
      }
     },
     "localname": "MinorityInterest",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsNonredeemableDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_MinorityInterestAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Stockholders' Equity Attributable to Noncontrolling Interest [Abstract]",
        "terseLabel": "Nonredeemable noncontrolling interests"
       }
      }
     },
     "localname": "MinorityInterestAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsNonredeemableDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders": {
     "auth_ref": [
      "r190"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Decrease in noncontrolling interest balance from payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders.",
        "label": "Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders",
        "negatedLabel": "Distributions to noncontrolling interests"
       }
      }
     },
     "localname": "MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_MinorityInterestDisclosureTextBlock": {
     "auth_ref": [
      "r273"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for noncontrolling interest in consolidated subsidiaries, which could include the name of the subsidiary, the ownership percentage held by the parent, the ownership percentage held by the noncontrolling owners, the amount of the noncontrolling interest, the location of this amount on the balance sheet (when not reported separately), an explanation of the increase or decrease in the amount of the noncontrolling interest, the noncontrolling interest share of the net Income or Loss of the subsidiary, the location of this amount on the income statement (when not reported separately), the nature of the noncontrolling interest such as background information and terms, the amount of the noncontrolling interest represented by preferred stock, a description of the preferred stock, and the dividend requirements of the preferred stock.",
        "label": "Noncontrolling Interest Disclosure [Text Block]",
        "terseLabel": "Noncontrolling Interests"
       }
      }
     },
     "localname": "MinorityInterestDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterests"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_MinorityInterestLineItems": {
     "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": "Noncontrolling Interest [Line Items]",
        "terseLabel": "Noncontrolling Interests That Are Not Subject to Redemption Rights"
       }
      }
     },
     "localname": "MinorityInterestLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsNonredeemableDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_MinorityInterestTable": {
     "auth_ref": [
      "r44",
      "r71",
      "r254",
      "r263"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule of noncontrolling interest disclosure which includes the name of the subsidiary, the ownership percentage held by the parent, the ownership percentage held by the noncontrolling owners, the amount of the noncontrolling interest, the location of this amount on the balance sheet (when not reported separately), an explanation of the increase or decrease in the amount of the noncontrolling interest, the noncontrolling interest share of the net Income or Loss of the subsidiary, the location of this amount on the income statement (when not reported separately), the nature of the noncontrolling interest such as background information and terms, the amount of the noncontrolling interest represented by preferred stock, a description of the preferred stock, and the dividend requirements of the preferred stock.",
        "label": "Noncontrolling Interest [Table]"
       }
      }
     },
     "localname": "MinorityInterestTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsNonredeemableDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_MovementInMinorityInterestRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]",
        "terseLabel": "Roll forward of redeemable noncontrolling interests in consolidated seed investment products"
       }
      }
     },
     "localname": "MovementInMinorityInterestRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInFinancingActivities": {
     "auth_ref": [
      "r84"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "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 financing activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInFinancingActivities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Net Cash Provided by (Used in) Financing Activities [Abstract]",
        "terseLabel": "Financing activities:"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInFinancingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInInvestingActivities": {
     "auth_ref": [
      "r84"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "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 investing activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInInvestingActivities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Net Cash Provided by (Used in) Investing Activities [Abstract]",
        "terseLabel": "Investing activities:"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInInvestingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInOperatingActivities": {
     "auth_ref": [
      "r84",
      "r86",
      "r89"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "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 operating activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInOperatingActivities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Net Cash Provided by (Used in) Operating Activities [Abstract]",
        "terseLabel": "Operating activities:"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetIncomeLossAttributableToNoncontrollingInterest": {
     "auth_ref": [
      "r59",
      "r62",
      "r259",
      "r271"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 2.0,
       "parentTag": "us-gaap_UndistributedEarnings",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of Net Income (Loss) attributable to noncontrolling interest.",
        "label": "Net Income (Loss) Attributable to Noncontrolling Interest",
        "negatedLabel": "Net loss (income) attributable to noncontrolling interests"
       }
      }
     },
     "localname": "NetIncomeLossAttributableToNoncontrollingInterest",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic": {
     "auth_ref": [
      "r99",
      "r105"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.",
        "label": "Net Income (Loss) Available to Common Stockholders, Basic",
        "totalLabel": "Net income (loss) attributable to JHG common shareholders"
       }
      }
     },
     "localname": "NetIncomeLossAvailableToCommonStockholdersBasic",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems": {
     "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": "New Accounting Pronouncements or Change in Accounting Principle [Line Items]",
        "terseLabel": "Recent Accounting Pronouncements"
       }
      }
     },
     "localname": "NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureBasisOfPresentationAndSignificantAccountingPoliciesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable": {
     "auth_ref": [
      "r98",
      "r100"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Summarization of the changes in an accounting principle or a new accounting pronouncement, including the line items affected by the change and the financial effects of the change on those particular line items.",
        "label": "New Accounting Pronouncements or Change in Accounting Principle [Table]"
       }
      }
     },
     "localname": "NewAccountingPronouncementsOrChangeInAccountingPrincipleTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureBasisOfPresentationAndSignificantAccountingPoliciesDetails"
     ],
     "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 Adopted"
       }
      }
     },
     "localname": "NewAccountingPronouncementsPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureBasisOfPresentationAndSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_NoncontrollingInterestAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Noncontrolling Interests"
       }
      }
     },
     "localname": "NoncontrollingInterestAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_NoncontrollingInterestMember": {
     "auth_ref": [
      "r253"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This element represents that portion of equity (net assets) in a subsidiary not attributable, directly or indirectly, to the parent. A noncontrolling interest is sometimes called a minority interest.",
        "label": "Noncontrolling Interest [Member]",
        "terseLabel": "Nonredeemable noncontrolling interests"
       }
      }
     },
     "localname": "NoncontrollingInterestMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_NondesignatedMember": {
     "auth_ref": [
      "r277"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Derivative instrument not designated as hedging instrument under Generally Accepted Accounting Principles (GAAP).",
        "label": "Nondesignated [Member]",
        "terseLabel": "Not Designated as Hedging Instrument"
       }
      }
     },
     "localname": "NondesignatedMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_NonredeemableNoncontrollingInterest": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Portion of equity (net assets) in a subsidiary not attributable, directly or indirectly, to the parent entity which is not redeemable by the parent entity.",
        "label": "Nonredeemable Noncontrolling Interest",
        "terseLabel": "Nonredeemable noncontrolling interests"
       }
      }
     },
     "localname": "NonredeemableNoncontrollingInterest",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent": {
     "auth_ref": [
      "r57",
      "r65"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after tax, before reclassification adjustments, of other comprehensive income (loss), attributable to parent.",
        "label": "OCI, before Reclassifications, Net of Tax, Attributable to Parent",
        "terseLabel": "Other comprehensive income (loss)"
       }
      }
     },
     "localname": "OciBeforeReclassificationsNetOfTaxAttributableToParent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OffsettingDerivativeAssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Offsetting Derivative Assets [Abstract]",
        "terseLabel": "Assets"
       }
      }
     },
     "localname": "OffsettingDerivativeAssetsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OffsettingDerivativeLiabilitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Offsetting Derivative Liabilities [Abstract]",
        "terseLabel": "Liabilities"
       }
      }
     },
     "localname": "OffsettingDerivativeLiabilitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OperatingIncomeLoss": {
     "auth_ref": [],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 1.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The net result for the period of deducting operating expenses from operating revenues.",
        "label": "Operating Income (Loss)",
        "totalLabel": "Operating income (loss)"
       }
      }
     },
     "localname": "OperatingIncomeLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherAssetsCurrent": {
     "auth_ref": [
      "r45"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureConsolidationVresDetails": {
       "order": 3.0,
       "parentTag": "jhg_VotingRightsEntitiesConsolidatedCarryingAmountAssetsAndLiabilitiesNet",
       "weight": 1.0
      },
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 5.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of current assets classified as other.",
        "label": "Other Assets, Current",
        "terseLabel": "Other current assets"
       }
      }
     },
     "localname": "OtherAssetsCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidationVresDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherAssetsNoncurrent": {
     "auth_ref": [
      "r32"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 6.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of noncurrent assets classified as other.",
        "label": "Other Assets, Noncurrent",
        "terseLabel": "Other non-current assets"
       }
      }
     },
     "localname": "OtherAssetsNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax": {
     "auth_ref": [
      "r51",
      "r54",
      "r307",
      "r308",
      "r309",
      "r310"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 1.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after tax, before reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.",
        "label": "Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax",
        "terseLabel": "Foreign currency translation gains (losses)"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax": {
     "auth_ref": [
      "r57"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before tax and reclassification adjustments of other comprehensive income (loss).",
        "label": "Other Comprehensive Income (Loss), before Reclassifications, before Tax",
        "terseLabel": "Pre-tax amount"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossOciDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax": {
     "auth_ref": [
      "r57",
      "r65"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after tax, before reclassification adjustments of other comprehensive income (loss).",
        "label": "Other Comprehensive Income (Loss), before Reclassifications, Net of Tax",
        "verboseLabel": "Net amount"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossOciDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax": {
     "auth_ref": [
      "r55",
      "r239"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of tax expense (benefit) allocated to other comprehensive income (loss) before reclassification adjustment from accumulated other comprehensive income (loss).",
        "label": "Other Comprehensive Income (Loss) before Reclassifications, Tax",
        "verboseLabel": "Tax impact"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossBeforeReclassificationsTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossOciDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTax": {
     "auth_ref": [
      "r60",
      "r63",
      "r65",
      "r185"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 1.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after tax and reclassification adjustments of other comprehensive income (loss).",
        "label": "Other Comprehensive Income (Loss), Net of Tax",
        "totalLabel": "Total other comprehensive income (loss)"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest": {
     "auth_ref": [
      "r60",
      "r63",
      "r255",
      "r256",
      "r261"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 2.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after tax of other comprehensive income (loss) attributable to noncontrolling interests.",
        "label": "Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest",
        "negatedLabel": "Other comprehensive loss (income) attributable to noncontrolling interests",
        "negatedTerseLabel": "Less: other comprehensive loss (income) attributable to noncontrolling interests"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent": {
     "auth_ref": [
      "r60",
      "r63",
      "r255",
      "r256",
      "r261"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after tax of other comprehensive income (loss) attributable to parent entity.",
        "label": "Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent",
        "totalLabel": "Other comprehensive income (loss) attributable to JHG"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherInvestmentsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Primary financial statement caption encompassing other investments.",
        "label": "Other Investments [Member]",
        "terseLabel": "Other investments"
       }
      }
     },
     "localname": "OtherInvestmentsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_OtherLiabilitiesNoncurrent": {
     "auth_ref": [
      "r40"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 6.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer.",
        "label": "Other Liabilities, Noncurrent",
        "terseLabel": "Other non-current liabilities"
       }
      }
     },
     "localname": "OtherLiabilitiesNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherNoncashIncomeExpense": {
     "auth_ref": [
      "r89"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 11.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of income (expense) included in net income that results in no cash inflow (outflow), classified as other.",
        "label": "Other Noncash Income (Expense).",
        "negatedLabel": "Other, net"
       }
      }
     },
     "localname": "OtherNoncashIncomeExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherNonoperatingIncomeExpense": {
     "auth_ref": [
      "r74"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 4.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of income (expense) related to nonoperating activities, classified as other.",
        "label": "Other Nonoperating Income (Expense)",
        "verboseLabel": "Other non-operating income, net"
       }
      }
     },
     "localname": "OtherNonoperatingIncomeExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities": {
     "auth_ref": [
      "r80"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash outflow, not made soon after acquisition date of business combination, to settle contingent consideration liability up to amount recognized at acquisition date, including, but not limited to, measurement period adjustment and less amount paid soon after acquisition date.",
        "label": "Payment for Contingent Consideration Liability, Financing Activities",
        "negatedLabel": "Payment of contingent consideration"
       }
      }
     },
     "localname": "PaymentForContingentConsiderationLiabilityFinancingActivities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentForContingentConsiderationLiabilityInvestingActivities": {
     "auth_ref": [
      "r78"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash outflow, made soon after acquisition date of business combination, to settle contingent consideration liability.",
        "label": "Payment for Contingent Consideration Liability, Investing Activities",
        "terseLabel": "Contingent cash consideration paid, for revenue target achieved"
       }
      }
     },
     "localname": "PaymentForContingentConsiderationLiabilityInvestingActivities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsAcquisitionOfKapstreamDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsForProceedsFromHedgeInvestingActivities": {
     "auth_ref": [
      "r96"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash outflow or inflow for a financial contract that meets the hedge criteria as either a cash flow hedge, fair value hedge, or hedge of a net investment in a foreign operation.",
        "label": "Payments for (Proceeds from) Hedge, Investing Activities",
        "negatedLabel": "Cash received (paid) on settled hedges, net"
       }
      }
     },
     "localname": "PaymentsForProceedsFromHedgeInvestingActivities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsOfDividendsCommonStock": {
     "auth_ref": [
      "r79"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 7.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.",
        "label": "Payments of Ordinary Dividends, Common Stock",
        "negatedLabel": "Dividends paid to shareholders",
        "terseLabel": "Cash dividends paid"
       }
      }
     },
     "localname": "PaymentsOfDividendsCommonStock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsOfDividendsMinorityInterest": {
     "auth_ref": [
      "r79"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash outflow in the form of ordinary dividends provided by the non-wholly owned subsidiary to noncontrolling interests.",
        "label": "Payments of Ordinary Dividends, Noncontrolling Interest",
        "negatedLabel": "Distributions to noncontrolling interests"
       }
      }
     },
     "localname": "PaymentsOfDividendsMinorityInterest",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireProductiveAssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Payments to Acquire Productive Assets [Abstract]",
        "verboseLabel": "Proceeds from (purchase of):"
       }
      }
     },
     "localname": "PaymentsToAcquireProductiveAssetsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PaymentsToAcquirePropertyPlantAndEquipment": {
     "auth_ref": [
      "r77"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "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": "Property, equipment and software"
       }
      }
     },
     "localname": "PaymentsToAcquirePropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock": {
     "auth_ref": [
      "r214"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for pension and other postretirement benefits.",
        "label": "Pension and Other Postretirement Benefits Disclosure [Text Block]",
        "terseLabel": "Retirement Benefit Plans"
       }
      }
     },
     "localname": "PensionAndOtherPostretirementBenefitsDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureRetirementBenefitPlans"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_PortionAtFairValueFairValueDisclosureMember": {
     "auth_ref": [
      "r298"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Measured at fair value for financial reporting purposes.",
        "label": "Portion At Fair Value Fair Value Disclosure [Member]",
        "terseLabel": "Portion at Fair Value Measurement [Member]"
       }
      }
     },
     "localname": "PortionAtFairValueFairValueDisclosureMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PostemploymentBenefitsLiabilityNoncurrent": {
     "auth_ref": [
      "r197"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 5.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "For a classified balance sheet, the carrying amount as of the balance sheet date of the portion of the obligations recognized for the various benefits provided to former or inactive employees, their beneficiaries, and covered dependents after employment but before retirement that is payable after one year (or beyond the operating cycle if longer).",
        "label": "Postemployment Benefits Liability, Noncurrent",
        "terseLabel": "Retirement benefit obligations, net"
       }
      }
     },
     "localname": "PostemploymentBenefitsLiabilityNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital": {
     "auth_ref": [
      "r76",
      "r83"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of distribution received from equity method investee for return of investment, classified as investing activities. Excludes distribution for return on investment, classified as operating activities.",
        "label": "Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital",
        "terseLabel": "Dividends received from equity-method investments"
       }
      }
     },
     "localname": "ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProductAndServiceOtherMember": {
     "auth_ref": [
      "r195"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Article or substance produced by nature, labor or machinery and act of providing assistance, classified as other.",
        "label": "Product And Service Other [Member]",
        "terseLabel": "Performance fees"
       }
      }
     },
     "localname": "ProductAndServiceOtherMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ProfitLoss": {
     "auth_ref": [
      "r59",
      "r62",
      "r82",
      "r124",
      "r125",
      "r255",
      "r258",
      "r260",
      "r271",
      "r272"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      },
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 1.0,
       "parentTag": "us-gaap_UndistributedEarnings",
       "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 (loss)",
        "totalLabel": "Net income (loss)"
       }
      }
     },
     "localname": "ProfitLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentNet": {
     "auth_ref": [
      "r19",
      "r20",
      "r169",
      "r357"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 2.0,
       "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",
        "verboseLabel": "Property, equipment and software, net"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PutOptionMember": {
     "auth_ref": [
      "r368"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A financial contract between two parties, the buyer and the seller (writer) of the option, where the buyer has the right but not the obligation to sell a commodity or financial instrument (the underlying instrument) to the seller (writer) at a certain time for a certain price (the strike price). The seller (writer) has the obligation to purchase the underlying asset at that strike price, if the buyer exercises the option.",
        "label": "Put Option [Member]",
        "terseLabel": "Options"
       }
      }
     },
     "localname": "PutOptionMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent": {
     "auth_ref": [
      "r57",
      "r65"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after tax of reclassification adjustments of other comprehensive income (loss) attributable to parent.",
        "label": "Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent",
        "negatedLabel": "Amounts reclassified from accumulated other comprehensive loss"
       }
      }
     },
     "localname": "ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RedeemableNoncontrollingInterestByLegalEntityTable": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule of redeemable noncontrolling interest (as defined) included in the statement of financial position as either a liability or temporary equity. As of the date of the statement of financial position, such redeemable noncontrolling interest is currently redeemable, as defined, for cash or other assets of the entity at (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the entity.",
        "label": "Redeemable Noncontrolling Interest, by Legal Entity [Table]"
       }
      }
     },
     "localname": "RedeemableNoncontrollingInterestByLegalEntityTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RedeemableNoncontrollingInterestEquityFairValue": {
     "auth_ref": [
      "r181",
      "r182",
      "r183",
      "r184"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The aggregate fair value as of the reporting date of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity.",
        "label": "Redeemable Noncontrolling Interest, Equity, Fair Value",
        "periodEndLabel": "Closing balance",
        "periodStartLabel": "Opening balance",
        "terseLabel": "REDEEMABLE NONCONTROLLING INTERESTS",
        "verboseLabel": "Total redeemable noncontrolling interests"
       }
      }
     },
     "localname": "RedeemableNoncontrollingInterestEquityFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RedeemableNoncontrollingInterestLineItems": {
     "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": "Redeemable Noncontrolling Interest [Line Items]",
        "terseLabel": "Redeemable Noncontrolling Interests"
       }
      }
     },
     "localname": "RedeemableNoncontrollingInterestLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsRedeemableDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RedeemableNoncontrollingInterestTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of redeemable noncontrolling interest (as defined) included in the statement of financial position as either a liability or temporary equity. As of the date of the statement of financial position, such redeemable noncontrolling interest is currently redeemable, as defined, for cash or other assets of the entity at (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the entity.",
        "label": "Redeemable Noncontrolling Interest [Table Text Block]",
        "terseLabel": "Summary of redeemable noncontrolling interests"
       }
      }
     },
     "localname": "RedeemableNoncontrollingInterestTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureNoncontrollingInterestsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_RetainedEarningsAccumulatedDeficit": {
     "auth_ref": [
      "r27",
      "r190",
      "r354"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 5.0,
       "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RetainedEarningsMember": {
     "auth_ref": [],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax": {
     "auth_ref": [
      "r193",
      "r194"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 1.0,
       "parentTag": "us-gaap_OperatingIncomeLoss",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.",
        "label": "Revenue from Contract with Customer, Including Assessed Tax",
        "terseLabel": "Total revenue"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerIncludingAssessedTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RevenuesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Revenues [Abstract]",
        "terseLabel": "Revenue:"
       }
      }
     },
     "localname": "RevenuesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock": {
     "auth_ref": [
      "r57"
     ],
     "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 the changes in accumulated other comprehensive loss, net of tax"
       }
      }
     },
     "localname": "ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable": {
     "auth_ref": [
      "r118"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock": {
     "auth_ref": [
      "r118"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of 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 Text Block]",
        "terseLabel": "Schedule of anti-dilutive securities that have not been included in the calculation of weighted average diluted shares outstanding"
       }
      }
     },
     "localname": "ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable": {
     "auth_ref": [
      "r251"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule of information about a contingent payment arrangement including the terms that will result in payment and the accounting treatment that will be followed if such contingency occurs, including the potential impact on earnings per share if the contingency is to be settled in shares of common stock of the entity. The description also may include the period over which amounts are expected to be paid, and changes in the amount since the previous reporting period. This also includes contingent options and commitments.",
        "label": "Schedule of Business Acquisitions by Acquisition, Contingent Consideration [Table]"
       }
      }
     },
     "localname": "ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsContingentConsiderationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable": {
     "auth_ref": [
      "r243",
      "r244"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule reflecting each material business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities.",
        "label": "Schedule of Business Acquisitions, by Acquisition [Table]"
       }
      }
     },
     "localname": "ScheduleOfBusinessAcquisitionsByAcquisitionTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsAcquisitionOfKapstreamDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock": {
     "auth_ref": [
      "r49"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of components of comprehensive income (loss). Includes, but is not limited to, foreign currency translation adjustments, foreign currency transactions  designated as economic hedges of a net investment in foreign entity, gain (loss) and prior service cost (credit) for pension plans and other postretirement benefit plans.",
        "label": "Comprehensive Income (Loss) [Table Text Block]",
        "terseLabel": "Components of other comprehensive income (loss), net of tax"
       }
      }
     },
     "localname": "ScheduleOfComprehensiveIncomeLossTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfDebtInstrumentsTextBlock": {
     "auth_ref": [
      "r39",
      "r94",
      "r186",
      "r187",
      "r188",
      "r189",
      "r312",
      "r313",
      "r315",
      "r350"
     ],
     "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": "Components of debt"
       }
      }
     },
     "localname": "ScheduleOfDebtInstrumentsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDebtTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock": {
     "auth_ref": [
      "r1",
      "r3",
      "r4",
      "r5",
      "r6",
      "r7",
      "r8",
      "r10",
      "r12",
      "r13",
      "r14",
      "r172",
      "r173"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of information related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component.",
        "label": "Disposal Groups, Including Discontinued Operations [Table Text Block]",
        "terseLabel": "Schedule of gain on sale"
       }
      }
     },
     "localname": "ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureDispositionsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock": {
     "auth_ref": [
      "r119"
     ],
     "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": "Summary of earnings (loss) per share calculation"
       }
      }
     },
     "localname": "ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable": {
     "auth_ref": [
      "r216",
      "r218",
      "r220"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about amount recognized for award under share-based payment arrangement. Includes, but is not limited to, amount expensed in statement of income or comprehensive income, amount capitalized in statement of financial position, and corresponding reporting line item in financial statements.",
        "label": "Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table]"
       }
      }
     },
     "localname": "ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureLongTermIncentiveAndEmployeeCompensationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock": {
     "auth_ref": [
      "r285",
      "r286"
     ],
     "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": "Schedule of assets and liabilities presented in the financial statements or disclosed in the notes to the financial statements at fair value on a recurring basis"
       }
      }
     },
     "localname": "ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable": {
     "auth_ref": [
      "r154",
      "r158"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.",
        "label": "Schedule of Finite-Lived Intangible Assets [Table]"
       }
      }
     },
     "localname": "ScheduleOfFiniteLivedIntangibleAssetsTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsTables"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock": {
     "auth_ref": [
      "r150"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of goodwill and intangible assets, which may be broken down by segment or major class.",
        "label": "Schedule of Intangible Assets and Goodwill [Table Text Block]",
        "verboseLabel": "Summary of goodwill and intangible assets"
       }
      }
     },
     "localname": "ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfNetBenefitCostsTableTextBlock": {
     "auth_ref": [
      "r202"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments.",
        "label": "Schedule of Net Benefit Costs [Table Text Block]",
        "terseLabel": "Schedule of components of net periodic benefit credit"
       }
      }
     },
     "localname": "ScheduleOfNetBenefitCostsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureRetirementBenefitPlansTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock": {
     "auth_ref": [
      "r275"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the notional amounts of outstanding derivative positions.",
        "label": "Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]",
        "terseLabel": "Schedule of derivative instruments"
       }
      }
     },
     "localname": "ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock": {
     "auth_ref": [
      "r158"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the amount of amortization expense expected to be recorded in succeeding fiscal years for finite-lived intangible assets.",
        "label": "Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]",
        "verboseLabel": "Schedule of expected future amortization"
       }
      }
     },
     "localname": "ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SecuritiesAssetsMember": {
     "auth_ref": [
      "r131"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A share, participation, or other interest in property or in an enterprise of the issuer or an obligation of the issuer that (a) either is represented by an instrument issued in bearer or registered form or, if not represented by an instrument, is registered in books maintained to record transfers by or on behalf of the issuer, (b) is of a type commonly dealt in on securities exchanges or markets or, when represented by an instrument, is commonly recognized in any area in which it is issued or dealt in as a medium for investment, and (c) either is one of a class or series or by its terms is divisible into a class or series of shares, participations, interest, or obligations.",
        "label": "Securities Assets [Member]",
        "terseLabel": "Securities"
       }
      }
     },
     "localname": "SecuritiesAssetsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SecuritiesInvestmentMember": {
     "auth_ref": [
      "r365",
      "r369"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This member categorizes all investments in securities to segregate them from other than security investments.",
        "label": "Securities Investment [Member]",
        "terseLabel": "Investment securities"
       }
      }
     },
     "localname": "SecuritiesInvestmentMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SellingExpense": {
     "auth_ref": [
      "r72"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": 5.0,
       "parentTag": "us-gaap_CostsAndExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Expenses recognized in the period that are directly related to the selling and distribution of products or services.",
        "label": "Selling Expense",
        "terseLabel": "Distribution expenses"
       }
      }
     },
     "localname": "SellingExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensation": {
     "auth_ref": [
      "r87"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 6.0,
       "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 Compensation",
        "terseLabel": "Stock-based compensation plan expense"
       }
      }
     },
     "localname": "ShareBasedCompensation",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1": {
     "auth_ref": [
      "r217"
     ],
     "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 period"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureLongTermIncentiveAndEmployeeCompensationDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_ShareholderServiceMember": {
     "auth_ref": [
      "r195"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Shareholder assistance, including, but not limited to, answering shareholder inquiry and providing shareholder with information about investment.",
        "label": "Shareholder Service [Member]",
        "terseLabel": "Shareowner servicing fees"
       }
      }
     },
     "localname": "ShareholderServiceMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShortTermInvestmentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Short-term Investments [Abstract]",
        "terseLabel": "Short-term investments:"
       }
      }
     },
     "localname": "ShortTermInvestmentsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShortTermInvestmentsMember": {
     "auth_ref": [
      "r377"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Investments which are not otherwise included in another category or item that the entity has the intent to sell or dispose of within one year from the date of the balance sheet.",
        "label": "Short Term Investments [Member]",
        "terseLabel": "Investment securities"
       }
      }
     },
     "localname": "ShortTermInvestmentsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_StatementEquityComponentsAxis": {
     "auth_ref": [
      "r43",
      "r185"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by component of equity.",
        "label": "Equity Components [Axis]"
       }
      }
     },
     "localname": "StatementEquityComponentsAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails",
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossOciDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Statement [Line Items]",
        "terseLabel": "Statement"
       }
      }
     },
     "localname": "StatementLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossOciDetails",
      "http://www.janus.com/role/DisclosureConsolidationViesDetails",
      "http://www.janus.com/role/DisclosureConsolidationVresDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables",
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfCashFlowsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS"
       }
      }
     },
     "localname": "StatementOfCashFlowsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfFinancialPositionAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "CONDENSED CONSOLIDATED BALANCE SHEETS"
       }
      }
     },
     "localname": "StatementOfFinancialPositionAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfStockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY"
       }
      }
     },
     "localname": "StatementOfStockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementTable": {
     "auth_ref": [],
     "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidationViesDetails",
      "http://www.janus.com/role/DisclosureConsolidationVresDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesTables",
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StockRepurchasedDuringPeriodShares": {
     "auth_ref": [
      "r24",
      "r25",
      "r185",
      "r190"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.",
        "label": "Stock Repurchased During Period, Shares",
        "negatedLabel": "Share buyback program (in shares)"
       }
      }
     },
     "localname": "StockRepurchasedDuringPeriodShares",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockRepurchasedDuringPeriodValue": {
     "auth_ref": [
      "r24",
      "r25",
      "r185",
      "r190"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.",
        "label": "Stock Repurchased During Period, Value",
        "negatedLabel": "Share buyback program"
       }
      }
     },
     "localname": "StockRepurchasedDuringPeriodValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockholdersEquity": {
     "auth_ref": [
      "r25",
      "r28",
      "r29",
      "r128"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest",
       "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/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureAccumulatedOtherComprehensiveLossDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest": {
     "auth_ref": [
      "r253",
      "r254",
      "r270"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.",
        "label": "Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest",
        "periodEndLabel": "Balance",
        "periodStartLabel": "Balance",
        "totalLabel": "Total equity"
       }
      }
     },
     "localname": "StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]",
        "terseLabel": "EQUITY"
       }
      }
     },
     "localname": "StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SummaryOfCreditDerivativesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Seeded investment products, credit protection"
       }
      }
     },
     "localname": "SummaryOfCreditDerivativesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SummaryOfInvestmentHoldingsLineItems": {
     "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": "Summary of Investment Holdings [Line Items]",
        "terseLabel": "Investments"
       }
      }
     },
     "localname": "SummaryOfInvestmentHoldingsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SupplementalCashFlowInformationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Supplemental Cash Flow Information [Abstract]",
        "terseLabel": "Supplemental cash flow information:"
       }
      }
     },
     "localname": "SupplementalCashFlowInformationAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_TotalReturnSwapMember": {
     "auth_ref": [
      "r274"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Contracts in which one party makes payments at a fixed or variable rate while the counterparty makes payments based on an asset, including the income and capital gains derived therefrom.",
        "label": "Total Return Swap [Member]",
        "terseLabel": "Total return swaps"
       }
      }
     },
     "localname": "TotalReturnSwapMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_TrademarksMember": {
     "auth_ref": [
      "r245"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Rights acquired through registration of a trademark to gain or protect exclusive use of a business name, symbol or other device or style.",
        "label": "Trademarks [Member]",
        "terseLabel": "Trademarks"
       }
      }
     },
     "localname": "TrademarksMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureGoodwillAndIntangibleAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain": {
     "auth_ref": [
      "r325"
     ],
     "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": "Transfers And Servicing Of Financial Instruments Types Of Financial Instruments [Domain]",
        "terseLabel": "Financial Instruments [Domain]"
       }
      }
     },
     "localname": "TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesOffsettingDerivativesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_TreasuryStockMember": {
     "auth_ref": [
      "r42",
      "r191"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Shares of an entity that have been repurchased by the entity. This stock has no voting rights and receives no dividends. Note that treasury stock may be recorded at its total cost or separately as par (or stated) value and additional paid in capital. Classified within stockholders' equity if nonredeemable or redeemable solely at the option of the issuer. Classified within temporary equity if redemption is outside the control of the issuer.",
        "label": "Treasury Stock [Member]",
        "terseLabel": "Treasury shares"
       }
      }
     },
     "localname": "TreasuryStockMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfChangesInEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_TreasuryStockShares": {
     "auth_ref": [
      "r42",
      "r191"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.",
        "label": "Treasury Stock, Shares",
        "terseLabel": "Treasury shares (in shares)"
       }
      }
     },
     "localname": "TreasuryStockShares",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_TreasuryStockValue": {
     "auth_ref": [
      "r42",
      "r191",
      "r192"
     ],
     "calculation": {
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount allocated to treasury stock. Treasury stock is common and preferred shares of an entity that were issued, repurchased by the entity, and are held in its treasury.",
        "label": "Treasury Stock, Value",
        "negatedLabel": "Treasury shares (2,739,678 and 3,545,812 shares held, respectively)"
       }
      }
     },
     "localname": "TreasuryStockValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TypeOfAdoptionMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Adoption and early adoption of sources of change to generally accepted accounting principles (GAAP) in the United States. The FASB released the FASB Accounting Standards Codification as the authoritative source of literature effective for interim and annual periods ending after September 15, 2009. As part of the Codification process, the FASB issues Accounting Standards Updates to amend the Codification but otherwise the Accounting Standards Updates are not authoritative in their own right. All previous accounting standards (such as FASB Statements of Financial Accounting Standards, FASB Interpretations, FASB Staff Positions, Emerging Issues Task Force Consensuses, other pronouncements of the FASB or other designated bodies, or other forms of GAAP are considered accounting pronouncements) were superseded upon the adoption of the Codification. For an interim period, references to the superseded standards are included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.",
        "label": "Type Of Adoption [Member]",
        "terseLabel": "Type of Adoption [Domain]"
       }
      }
     },
     "localname": "TypeOfAdoptionMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureBasisOfPresentationAndSignificantAccountingPoliciesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_UndistributedEarnings": {
     "auth_ref": [
      "r109",
      "r110",
      "r113",
      "r114",
      "r115"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic",
       "weight": 1.0
      },
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The earnings that is allocated to common stock and participating securities to the extent that each security may share in earnings as if all of the earnings for the period had been distributed.",
        "label": "Net Income (Loss) Attributable to Parent",
        "terseLabel": "Net income (loss) attributable to JHG",
        "totalLabel": "Net income (loss) attributable to JHG"
       }
      }
     },
     "localname": "UndistributedEarnings",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic": {
     "auth_ref": [
      "r111"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic",
       "weight": -1.0
      }
     },
     "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": "Allocation of earnings to participating stock-based awards"
       }
      }
     },
     "localname": "UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecognizedTaxBenefits": {
     "auth_ref": [
      "r224",
      "r230"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of unrecognized tax benefits.",
        "label": "Unrecognized Tax Benefits",
        "terseLabel": "Unrecognized tax liability"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefits",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis": {
     "auth_ref": [
      "r264",
      "r265",
      "r267"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by category of Variable Interest Entity (VIE).",
        "label": "Variable Interest Entities [Axis]"
       }
      }
     },
     "localname": "VariableInterestEntitiesByClassificationOfEntityAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidationViesDetails",
      "http://www.janus.com/role/DisclosureConsolidationVresDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_VariableInterestEntityNotPrimaryBeneficiaryAggregatedDisclosureMember": {
     "auth_ref": [
      "r268"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Aggregated disclosures of similar Variable Interest Entities (VIE) which are not included in the consolidated financial statements of the entity because the entity does not have a controlling financial interest (not the primary beneficiary). Such disclosures may include how similar entities are aggregated, if separate reporting would not provide more useful information.",
        "label": "Variable Interest Entity Not Primary Beneficiary Aggregated Disclosure [Member]",
        "terseLabel": "Unconsolidated VIEs"
       }
      }
     },
     "localname": "VariableInterestEntityNotPrimaryBeneficiaryAggregatedDisclosureMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureConsolidationViesDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_VariableInterestEntityPrimaryBeneficiaryAggregatedDisclosureMember": {
     "auth_ref": [
      "r269"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosures of similar consolidated Variable Interest Entities (VIE),in aggregate, including how similar entities are aggregated, if separate reporting would not provide more useful information.",
        "label": "Variable Interest Entity Primary Beneficiary Aggregated Disclosure [Member]",
        "terseLabel": "Consolidated VIEs"
       }
      }
     },
     "localname": "VariableInterestEntityPrimaryBeneficiaryAggregatedDisclosureMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails",
      "http://www.janus.com/role/DisclosureInvestmentSecuritiesGeneralDisclosureDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_VariableInterestEntityPrimaryBeneficiaryMember": {
     "auth_ref": [
      "r264"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Variable Interest Entities (VIE) in which the entity has a controlling financial interest (as defined) and of which it is therefore the primary beneficiary. A controlling financial interest is determined based on both: (a) the entity's power to direct activities of the VIE that most significantly impact the VIE's economic performance and (b) the entity's obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE. VIEs of which the entity is the primary beneficiary are included in the consolidated financial statements of the entity.",
        "label": "Variable Interest Entity Primary Beneficiary [Member]",
        "terseLabel": "Consolidated VIEs"
       }
      }
     },
     "localname": "VariableInterestEntityPrimaryBeneficiaryMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevel3RollforwardDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsLevelOfFairValueDetails",
      "http://www.janus.com/role/DisclosureFairValueMeasurementsValuationTechniquesAndSignificantUnobservableInputsDetails",
      "http://www.janus.com/role/StatementCondensedConsolidatedBalanceSheets",
      "http://www.janus.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding": {
     "auth_ref": [
      "r106",
      "r117"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.",
        "label": "Weighted Average Number of Shares Outstanding, Diluted",
        "totalLabel": "Weighted-average common shares outstanding - diluted"
       }
      }
     },
     "localname": "WeightedAverageNumberOfDilutedSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_WeightedAverageNumberOfSharesOutstandingBasic": {
     "auth_ref": [
      "r104",
      "r117"
     ],
     "calculation": {
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding",
       "weight": 1.0
      }
     },
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.",
        "label": "Weighted Average Number of Shares Outstanding, Basic",
        "verboseLabel": "Weighted-average common shares outstanding - basic"
       }
      }
     },
     "localname": "WeightedAverageNumberOfSharesOutstandingBasic",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.janus.com/role/DisclosureEarningsLossAndDividendsPerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    }
   },
   "unitCount": 6
  }
 },
 "std_ref": {
  "r0": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222160&loc=d3e1107-107759"
  },
  "r1": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222160&loc=SL51721533-107759"
  },
  "r10": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760"
  },
  "r100": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22583-107794"
  },
  "r101": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22644-107794"
  },
  "r102": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22658-107794"
  },
  "r103": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22663-107794"
  },
  "r104": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1448-109256"
  },
  "r105": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1377-109256"
  },
  "r106": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1505-109256"
  },
  "r107": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1252-109256"
  },
  "r108": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1500-109256"
  },
  "r109": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e2740-109256"
  },
  "r11": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5C",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(2)",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721675-107760"
  },
  "r110": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=SL5780132-109256"
  },
  "r111": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=SL5780133-109256"
  },
  "r112": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=SL5780133-109256"
  },
  "r113": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=SL5780133-109256"
  },
  "r114": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "65",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e2793-109256"
  },
  "r115": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "66",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e2814-109256"
  },
  "r116": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1337-109256"
  },
  "r117": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257"
  },
  "r118": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257"
  },
  "r119": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257"
  },
  "r12": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5C",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721675-107760"
  },
  "r120": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "52",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117327953&loc=d3e4984-109258"
  },
  "r121": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599"
  },
  "r122": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599"
  },
  "r123": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599"
  },
  "r124": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599"
  },
  "r125": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599"
  },
  "r126": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "40",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e9031-108599"
  },
  "r127": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "41",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e9038-108599"
  },
  "r128": {
   "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=27010918&loc=d3e74512-122707"
  },
  "r129": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118939692&loc=d3e27405-111563"
  },
  "r13": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721677-107760"
  },
  "r130": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118939692&loc=d3e27357-111563"
  },
  "r131": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "320",
   "URI": "http://asc.fasb.org/topic&trid=2196928"
  },
  "r132": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "321",
   "URI": "http://asc.fasb.org/topic&trid=75115024"
  },
  "r133": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "10",
   "Topic": "323",
   "URI": "http://asc.fasb.org/extlink&oid=117311354&loc=d3e32014-111567"
  },
  "r134": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "323",
   "URI": "http://asc.fasb.org/topic&trid=2196965"
  },
  "r135": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "325",
   "URI": "http://asc.fasb.org/topic&trid=2197064"
  },
  "r136": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919244-210447"
  },
  "r137": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447"
  },
  "r138": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919253-210447"
  },
  "r139": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919258-210447"
  },
  "r14": {
   "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"
  },
  "r140": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919230-210447"
  },
  "r141": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=118955579&loc=SL82922888-210455"
  },
  "r142": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=118955579&loc=SL82922895-210455"
  },
  "r143": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=118955579&loc=SL82922900-210455"
  },
  "r144": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=118942371&loc=SL82922954-210456"
  },
  "r145": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266"
  },
  "r146": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=99380562&loc=d3e13777-109266"
  },
  "r147": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975"
  },
  "r148": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267"
  },
  "r149": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(f)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267"
  },
  "r15": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/subtopic&trid=2122178"
  },
  "r150": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267"
  },
  "r151": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=108376223&loc=d3e13854-109267"
  },
  "r152": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=6388964&loc=d3e16212-109274"
  },
  "r153": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274"
  },
  "r154": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275"
  },
  "r155": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(b)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275"
  },
  "r156": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(d)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275"
  },
  "r157": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "((a)(1),(b))",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275"
  },
  "r158": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275"
  },
  "r159": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)(1)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275"
  },
  "r16": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765"
  },
  "r160": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)(2)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275"
  },
  "r161": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)(3)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275"
  },
  "r162": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(b)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275"
  },
  "r163": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(d)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275"
  },
  "r164": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(b)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275"
  },
  "r165": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(e)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=118172025&loc=SL118172731-207502"
  },
  "r166": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(f)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=118172025&loc=SL118172731-207502"
  },
  "r167": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "350",
   "URI": "http://asc.fasb.org/topic&trid=2144416"
  },
  "r168": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=109226348&loc=d3e2443-110228"
  },
  "r169": {
   "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"
  },
  "r17": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765"
  },
  "r170": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230"
  },
  "r171": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230"
  },
  "r172": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230"
  },
  "r173": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=109226691&loc=SL51724579-110230"
  },
  "r174": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "360",
   "URI": "http://asc.fasb.org/topic&trid=2155823"
  },
  "r175": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "440",
   "URI": "http://asc.fasb.org/topic&trid=2144648"
  },
  "r176": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349"
  },
  "r177": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=118942415&loc=d3e14615-108349"
  },
  "r178": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "450",
   "URI": "http://asc.fasb.org/topic&trid=2127136"
  },
  "r179": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(3)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870"
  },
  "r18": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6801-107765"
  },
  "r180": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "470",
   "URI": "http://asc.fasb.org/topic&trid=2208564"
  },
  "r181": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(12)(c)",
   "Topic": "480",
   "URI": "http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764"
  },
  "r182": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(16)(c)",
   "Topic": "480",
   "URI": "http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764"
  },
  "r183": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "14",
   "Topic": "480",
   "URI": "http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764"
  },
  "r184": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "15",
   "Topic": "480",
   "URI": "http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764"
  },
  "r185": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644"
  },
  "r186": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644"
  },
  "r187": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644"
  },
  "r188": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21521-112644"
  },
  "r189": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21538-112644"
  },
  "r19": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r190": {
   "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=27012166&loc=d3e187085-122770"
  },
  "r191": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655"
  },
  "r192": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=6405834&loc=d3e23315-112656"
  },
  "r193": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045"
  },
  "r194": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045"
  },
  "r195": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118944142&loc=SL49130690-203046-203046"
  },
  "r196": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118944142&loc=SL49130690-203046-203046"
  },
  "r197": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "10",
   "Topic": "712",
   "URI": "http://asc.fasb.org/extlink&oid=6410138&loc=d3e79691-111665"
  },
  "r198": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(1)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r199": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(2)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r2": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222160&loc=SL51721494-107759"
  },
  "r20": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r200": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(ii)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r201": {
   "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=118255775&loc=d3e1928-114920"
  },
  "r202": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(h)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r203": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(h)(1)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r204": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(h)(2)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r205": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(h)(3)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r206": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(h)(5)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r207": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(j)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r208": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(n)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r209": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(1)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920"
  },
  "r21": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r210": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(2)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920"
  },
  "r211": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(3)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920"
  },
  "r212": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(5)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920"
  },
  "r213": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921"
  },
  "r214": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "715",
   "URI": "http://asc.fasb.org/topic&trid=2235017"
  },
  "r215": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116855982&loc=d3e4534-113899"
  },
  "r216": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901"
  },
  "r217": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r218": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r219": {
   "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=116856206&loc=d3e5070-113901"
  },
  "r22": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(20))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r220": {
   "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=115993241&loc=d3e301413-122809"
  },
  "r221": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=118258462&loc=d3e11149-113907"
  },
  "r222": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=118258462&loc=d3e11178-113907"
  },
  "r223": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "718",
   "URI": "http://asc.fasb.org/topic&trid=2228938"
  },
  "r224": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=116821951&loc=SL37586934-109318"
  },
  "r225": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=116821951&loc=d3e31931-109318"
  },
  "r226": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319"
  },
  "r227": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319"
  },
  "r228": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)(3)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319"
  },
  "r229": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319"
  },
  "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=6877327&loc=d3e13212-122682"
  },
  "r230": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319"
  },
  "r231": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319"
  },
  "r232": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "19",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32840-109319"
  },
  "r233": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319"
  },
  "r234": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319"
  },
  "r235": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319"
  },
  "r236": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "217",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=117331294&loc=d3e36027-109320"
  },
  "r237": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB TOPIC 6.I)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=116825942&loc=d3e330036-122817"
  },
  "r238": {
   "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=116825942&loc=d3e330036-122817"
  },
  "r239": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=109238882&loc=d3e39076-109324"
  },
  "r24": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r240": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=109238882&loc=d3e38679-109324"
  },
  "r241": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "740",
   "URI": "http://asc.fasb.org/topic&trid=2144680"
  },
  "r242": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463"
  },
  "r243": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463"
  },
  "r244": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=79982066&loc=d3e1486-128463"
  },
  "r245": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=77890550&loc=d3e5263-128473"
  },
  "r246": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=77890550&loc=d3e5333-128473"
  },
  "r247": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "30",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476"
  },
  "r248": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "30",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=6911189&loc=d3e6411-128476"
  },
  "r249": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "30",
   "Subparagraph": "(b)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=116859824&loc=d3e6819-128478"
  },
  "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=6877327&loc=d3e13212-122682"
  },
  "r250": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(c)(1)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479"
  },
  "r251": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "c",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479"
  },
  "r252": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)(1)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=35744584&loc=d3e7008-128479"
  },
  "r253": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4568447-111683"
  },
  "r254": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4568740-111683"
  },
  "r255": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "19",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4569616-111683"
  },
  "r256": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4569643-111683"
  },
  "r257": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4613674-111683"
  },
  "r258": {
   "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"
  },
  "r259": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(2)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684"
  },
  "r26": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r260": {
   "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"
  },
  "r261": {
   "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"
  },
  "r262": {
   "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"
  },
  "r263": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684"
  },
  "r264": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=118582676&loc=d3e5710-111685"
  },
  "r265": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=118582676&loc=d3e5728-111685"
  },
  "r266": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=118582676&loc=SL6759159-111685"
  },
  "r267": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=118582676&loc=d3e5747-111685"
  },
  "r268": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=118582676&loc=SL6228884-111685"
  },
  "r269": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=118582676&loc=SL6228884-111685"
  },
  "r27": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r270": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4I",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116874947&loc=SL4590271-111686"
  },
  "r271": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4J",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116874947&loc=SL4591551-111686"
  },
  "r272": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4K",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116874947&loc=SL4591552-111686"
  },
  "r273": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "810",
   "URI": "http://asc.fasb.org/topic&trid=2197479"
  },
  "r274": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "83",
   "Publisher": "FASB",
   "Section": "15",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=117415099&loc=d3e34841-113949"
  },
  "r275": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959"
  },
  "r276": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959"
  },
  "r277": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=d3e41620-113959"
  },
  "r278": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959"
  },
  "r279": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959"
  },
  "r28": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r280": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4C",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959"
  },
  "r281": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624177-113959"
  },
  "r282": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624177-113959"
  },
  "r283": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624177-113959"
  },
  "r284": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4E",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624181-113959"
  },
  "r285": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r286": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r287": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bb)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r288": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bbb)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r289": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bbb)(1)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r29": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r290": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bbb)(2)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r291": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r292": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r293": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r294": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19279-110258"
  },
  "r295": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19279-110258"
  },
  "r296": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=SL6742756-110258"
  },
  "r297": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=SL6742756-110258"
  },
  "r298": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=116690757&loc=d3e13220-108610"
  },
  "r299": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=118260190&loc=d3e13433-108611"
  },
  "r3": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=d3e1361-107760"
  },
  "r30": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r300": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=118260190&loc=d3e13467-108611"
  },
  "r301": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=118260190&loc=d3e13476-108611"
  },
  "r302": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "31",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=75031198&loc=d3e14210-108612"
  },
  "r303": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=109240200&loc=d3e30690-110894"
  },
  "r304": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=109240200&loc=d3e30700-110894"
  },
  "r305": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=6450222&loc=d3e30840-110895"
  },
  "r306": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "230",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=98513438&loc=d3e33268-110906"
  },
  "r307": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32022-110900"
  },
  "r308": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "18",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32157-110900"
  },
  "r309": {
   "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"
  },
  "r31": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r310": {
   "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"
  },
  "r311": {
   "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"
  },
  "r312": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399"
  },
  "r313": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399"
  },
  "r314": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399"
  },
  "r315": {
   "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"
  },
  "r316": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888419&loc=SL77918643-209977"
  },
  "r317": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(1)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r318": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "850",
   "URI": "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864"
  },
  "r319": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "850",
   "URI": "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864"
  },
  "r32": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r320": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "855",
   "URI": "http://asc.fasb.org/extlink&oid=6842918&loc=SL6314020-165662"
  },
  "r321": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=118948506&loc=d3e107207-111719"
  },
  "r322": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=118948506&loc=d3e107207-111719"
  },
  "r323": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=118948506&loc=d3e107207-111719"
  },
  "r324": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=118948506&loc=d3e107207-111719"
  },
  "r325": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122625-111746"
  },
  "r326": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "340",
   "Topic": "928",
   "URI": "http://asc.fasb.org/extlink&oid=6473545&loc=d3e61844-108004"
  },
  "r327": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "235",
   "Subparagraph": "(a)",
   "Topic": "932",
   "URI": "http://asc.fasb.org/extlink&oid=68064819&loc=d3e61929-109447"
  },
  "r328": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "235",
   "Subparagraph": "(b)",
   "Topic": "932",
   "URI": "http://asc.fasb.org/extlink&oid=68064819&loc=d3e61929-109447"
  },
  "r329": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "235",
   "Subparagraph": "(a)",
   "Topic": "932",
   "URI": "http://asc.fasb.org/extlink&oid=68064819&loc=d3e62059-109447"
  },
  "r33": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r330": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "235",
   "Subparagraph": "(b)",
   "Topic": "932",
   "URI": "http://asc.fasb.org/extlink&oid=68064819&loc=d3e62059-109447"
  },
  "r331": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "235",
   "Subparagraph": "(a)",
   "Topic": "932",
   "URI": "http://asc.fasb.org/extlink&oid=68064819&loc=d3e62395-109447"
  },
  "r332": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "235",
   "Subparagraph": "(b)",
   "Topic": "932",
   "URI": "http://asc.fasb.org/extlink&oid=68064819&loc=d3e62395-109447"
  },
  "r333": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "33",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "235",
   "Subparagraph": "(a)",
   "Topic": "932",
   "URI": "http://asc.fasb.org/extlink&oid=68064819&loc=d3e62479-109447"
  },
  "r334": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "33",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "235",
   "Subparagraph": "(b)",
   "Topic": "932",
   "URI": "http://asc.fasb.org/extlink&oid=68064819&loc=d3e62479-109447"
  },
  "r335": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "35A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "235",
   "Subparagraph": "(a)",
   "Topic": "932",
   "URI": "http://asc.fasb.org/extlink&oid=68064819&loc=SL6807758-109447"
  },
  "r336": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "35A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "235",
   "Subparagraph": "(b)",
   "Topic": "932",
   "URI": "http://asc.fasb.org/extlink&oid=68064819&loc=SL6807758-109447"
  },
  "r337": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "235",
   "Subparagraph": "(c)(1)",
   "Topic": "932",
   "URI": "http://asc.fasb.org/extlink&oid=68064819&loc=d3e61872-109447"
  },
  "r338": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "235",
   "Subparagraph": "(c)(2)",
   "Topic": "932",
   "URI": "http://asc.fasb.org/extlink&oid=68064819&loc=d3e61872-109447"
  },
  "r339": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "20",
   "Topic": "940",
   "URI": "http://asc.fasb.org/extlink&oid=68072869&loc=d3e41242-110953"
  },
  "r34": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19,20)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r340": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "320",
   "Subparagraph": "(b)",
   "Topic": "940",
   "URI": "http://asc.fasb.org/extlink&oid=35711043&loc=d3e42429-110968"
  },
  "r341": {
   "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=6876686&loc=d3e534808-122878"
  },
  "r342": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(13))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r343": {
   "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=6876686&loc=d3e534808-122878"
  },
  "r344": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(22))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r345": {
   "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=6876686&loc=d3e534808-122878"
  },
  "r346": {
   "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=6876686&loc=d3e534808-122878"
  },
  "r347": {
   "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=116637391&loc=SL114874048-224260"
  },
  "r348": {
   "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=116637391&loc=SL114874048-224260"
  },
  "r349": {
   "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=116637391&loc=SL114874048-224260"
  },
  "r35": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r350": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "470",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823"
  },
  "r351": {
   "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=119400593&loc=d3e572229-122910"
  },
  "r352": {
   "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=119400593&loc=d3e572229-122910"
  },
  "r353": {
   "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=119400593&loc=d3e572229-122910"
  },
  "r354": {
   "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=119400593&loc=d3e572229-122910"
  },
  "r355": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(24))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910"
  },
  "r356": {
   "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=119400593&loc=d3e572229-122910"
  },
  "r357": {
   "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=119400593&loc=d3e572229-122910"
  },
  "r358": {
   "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=119400593&loc=d3e572229-122910"
  },
  "r359": {
   "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=116637232&loc=SL114874131-224263"
  },
  "r36": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.20)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r360": {
   "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=116637232&loc=SL114874131-224263"
  },
  "r361": {
   "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"
  },
  "r362": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13H",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "40",
   "Subparagraph": "(a)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=117419784&loc=SL117783719-158441"
  },
  "r363": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13H",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "40",
   "Subparagraph": "(b)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=117419784&loc=SL117783719-158441"
  },
  "r364": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "210",
   "Subparagraph": "(b)",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=99383244&loc=d3e12121-115841"
  },
  "r365": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12(2)(i))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611133-123010"
  },
  "r366": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12.2(ii))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611133-123010"
  },
  "r367": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12.Column C.3,4)",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611133-123010"
  },
  "r368": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12B.1)",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611197-123010"
  },
  "r369": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12C(1)(a))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611225-123010"
  },
  "r37": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.21)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r370": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12C(1)(b))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611225-123010"
  },
  "r371": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12C(2))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611225-123010"
  },
  "r372": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12C.1(b),2)",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611225-123010"
  },
  "r373": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12C.Column C.7)",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611225-123010"
  },
  "r374": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12C(2))-",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611225-123010"
  },
  "r375": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-13.Column C.6)",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611282-123010"
  },
  "r376": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-14.Column E.2,3)",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611322-123010"
  },
  "r377": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-15(Column A))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611379-123010"
  },
  "r378": {
   "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=6589523&loc=d3e617274-123014"
  },
  "r379": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Footnote 2))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024"
  },
  "r38": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r380": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Footnote 4))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024"
  },
  "r381": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b"
  },
  "r382": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "d1-1"
  },
  "r383": {
   "Name": "Form 10-Q",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "13",
   "Subsection": "a-13"
  },
  "r384": {
   "Name": "Forms 10-K, 10-Q, 20-F",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "13",
   "Subsection": "a-1-"
  },
  "r385": {
   "Name": "Regulation 12B",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b-2"
  },
  "r386": {
   "Name": "Regulation S-T",
   "Number": "232",
   "Publisher": "SEC",
   "Section": "405"
  },
  "r39": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r4": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=d3e1474-107760"
  },
  "r40": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.24)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r41": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r42": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.29,30)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r43": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r44": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r45": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r46": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.9)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r47": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312"
  },
  "r48": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313"
  },
  "r49": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e526-108580"
  },
  "r5": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721659-107760"
  },
  "r50": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a),(b),(c)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580"
  },
  "r51": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a-c)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580"
  },
  "r52": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(i),(j),(k)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580"
  },
  "r53": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580"
  },
  "r54": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e637-108580"
  },
  "r55": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e640-108580"
  },
  "r56": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e681-108580"
  },
  "r57": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669686-108580"
  },
  "r58": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL34724394-108580"
  },
  "r59": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580"
  },
  "r6": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721663-107760"
  },
  "r60": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580"
  },
  "r61": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580"
  },
  "r62": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669625-108580"
  },
  "r63": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669625-108580"
  },
  "r64": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e557-108580"
  },
  "r65": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118951672&loc=d3e1436-108581"
  },
  "r66": {
   "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=116634182&loc=SL114868664-224227"
  },
  "r67": {
   "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=116634182&loc=SL114868664-224227"
  },
  "r68": {
   "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=116634182&loc=SL114868664-224227"
  },
  "r69": {
   "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=116634182&loc=SL114868664-224227"
  },
  "r7": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721665-107760"
  },
  "r70": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r71": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.19)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r72": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.4)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r73": {
   "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=116634182&loc=SL114868664-224227"
  },
  "r74": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.9)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r75": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "220",
   "URI": "http://asc.fasb.org/topic&trid=2134417"
  },
  "r76": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585"
  },
  "r77": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585"
  },
  "r78": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585"
  },
  "r79": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585"
  },
  "r8": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721671-107760"
  },
  "r80": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585"
  },
  "r81": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3367-108585"
  },
  "r82": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3000-108585"
  },
  "r83": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21D",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=SL94080555-108585"
  },
  "r84": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "24",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3521-108585"
  },
  "r85": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3536-108585"
  },
  "r86": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3536-108585"
  },
  "r87": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585"
  },
  "r88": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585"
  },
  "r89": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585"
  },
  "r9": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760"
  },
  "r90": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3044-108585"
  },
  "r91": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=98513485&loc=d3e4297-108586"
  },
  "r92": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=98513485&loc=SL98516268-108586"
  },
  "r93": {
   "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=26873400&loc=d3e23780-122690"
  },
  "r94": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08.(e),(f))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690"
  },
  "r95": {
   "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=26873400&loc=d3e23780-122690"
  },
  "r96": {
   "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=26873400&loc=d3e24072-122690"
  },
  "r97": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "235",
   "URI": "http://asc.fasb.org/topic&trid=2122369"
  },
  "r98": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794"
  },
  "r99": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794"
  }
 },
 "version": "2.1"
}
