{ "instance": { "d175612d485bpos.htm": { "axisCustom": 0, "axisStandard": 4, "contextCount": 819, "dts": { "calculationLink": { "local": [ "jif-20220128_cal.xml" ] }, "definitionLink": { "local": [ "jif-20220128_def.xml" ] }, "inline": { "local": [ "d175612d485bpos.htm" ] }, "labelLink": { "local": [ "jif-20220128_lab.xml" ] }, "presentationLink": { "local": [ "jif-20220128_pre.xml" ] }, "schema": { "local": [ "jif-20220128.xsd" ], "remote": [ "https://xbrl.sec.gov/rr/2021/rr-2021.xsd", "http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd", "http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd", "http://www.xbrl.org/2003/xl-2003-12-31.xsd", "http://www.xbrl.org/2003/xlink-2003-12-31.xsd", "https://www.xbrl.org/dtr/type/2020-01-21/types.xsd", "http://www.xbrl.org/2005/xbrldt-2005.xsd", "https://xbrl.sec.gov/dei/2021/dei-2021.xsd", "http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd" ] } }, "elementCount": 402, "entityCount": 1, "hidden": { "http://xbrl.sec.gov/dei/2021": 159, "http://xbrl.sec.gov/rr/2021": 3876, "total": 4035 }, "keyCustom": 0, "keyStandard": 204, "memberCustom": 198, "memberStandard": 0, "nsprefix": "jif", "nsuri": "http://www.janushenderson.com/20220128", "report": { "R1": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "document", "isDefault": "false", "longName": "000000 - Document - Document and Entity Information {Elements}", "role": "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements", "shortName": "Document and Entity Information", "subGroupType": "", "uniqueAnchor": null }, "R10": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000099 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Balanced Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Balanced Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010464", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R11": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000109 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Contrarian Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Contrarian Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010475", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R12": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000119 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Enterprise Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Enterprise Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010490", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R13": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000129 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Forty Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Forty Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000025893", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R14": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000139 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Growth and Income Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Growth and Income Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010467", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R15": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000149 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Research Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Research Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010470", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R16": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000159 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Triton Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Triton Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010485", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R17": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000169 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Venture Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Venture Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010488", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R18": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000179 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Asia Equity Fund (Class A C S I N T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Asia Equity Fund (Class A C S I N T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000033204", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R19": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000189 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Emerging Markets Fund (Class A C S I N T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Emerging Markets Fund (Class A C S I N T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000057600", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R2": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000019 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Balanced Fund (Class A C S I N R T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Balanced Fund (Class A C S I N R T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010464", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R20": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000199 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson European Focus Fund (Class A C S I N T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "shortName": "Risk/Return Detail Data- Janus Henderson European Focus Fund (Class A C S I N T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000057603", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R21": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000209 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Global Equity Income Fund (Class A C S I N T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Global Equity Income Fund (Class A C S I N T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000057602", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R22": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000219 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Global Life Sciences Fund (Class A C S I N T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Global Life Sciences Fund (Class A C S I N T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000010494", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R23": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000229 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Global Real Estate Fund (Class A C S I N T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Global Real Estate Fund (Class A C S I N T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000025889", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R24": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000239 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Global Research Fund (Class A C S I N R T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Global Research Fund (Class A C S I N R T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010489", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R25": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000249 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Global Select Fund (Class A C S I N R T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Global Select Fund (Class A C S I N R T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010474", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R26": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000259 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Global Sustainable Equity Fund (Class A C S I N R T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Global Sustainable Equity Fund (Class A C S I N R T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000068819", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R27": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000269 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Global Technology and Innovation Fund (Class A C S I N T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Global Technology and Innovation Fund (Class A C S I N T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000010465", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R28": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000279 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson International Opportunities Fund (Class A C S I N R T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "shortName": "Risk/Return Detail Data- Janus Henderson International Opportunities Fund (Class A C S I N R T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000057601", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R29": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000289 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Overseas Fund (Class A C S I N R T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Overseas Fund (Class A C S I N R T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010476", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R3": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000029 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Contrarian Fund (Class A C S I N R T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Contrarian Fund (Class A C S I N R T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010475", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R30": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000299 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Asia Equity Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Asia Equity Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000033204", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R31": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000309 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Emerging Markets Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Emerging Markets Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000057600", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R32": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000319 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson European Focus Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson European Focus Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000057603", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R33": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000329 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Global Equity Income Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Global Equity Income Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000057602", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R34": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000339 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Global Life Sciences Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Global Life Sciences Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010494", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R35": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000349 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Global Real Estate Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Global Real Estate Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000025889", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R36": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000359 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Global Research Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Global Research Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010489", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R37": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000369 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Global Select Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Global Select Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010474", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R38": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000379 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Global Sustainable Equity Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Global Sustainable Equity Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000068819", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R39": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000389 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Global Technology and Innovation Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Global Technology and Innovation Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010465", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R4": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000039 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Enterprise Fund (Class A C S I N R T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Enterprise Fund (Class A C S I N R T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010490", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R40": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000399 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson International Opportunities Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson International Opportunities Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000057601", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R41": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000409 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Overseas Fund (Class D Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "shortName": "Risk/Return Detail Data- Janus Henderson Overseas Fund (Class D Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010476", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R42": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "040000 - Disclosure - Risk/Return Detail Data {Elements}", "role": "http://xbrl.sec.gov/rr/role/RiskReturnDetailData", "shortName": "Risk/Return Detail Data", "subGroupType": "", "uniqueAnchor": null }, "R5": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000049 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Forty Fund (Class A C S I N R T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Forty Fund (Class A C S I N R T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000025893", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R6": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000059 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Growth and Income Fund (Class A C S I N R T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Growth and Income Fund (Class A C S I N R T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010467", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R7": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000069 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Research Fund (Class A C S I N R T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Research Fund (Class A C S I N R T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010470", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R8": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000079 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Triton Fund (Class A C S I N R T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Triton Fund (Class A C S I N R T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010485", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "R9": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "first": true, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "disclosure", "isDefault": "false", "longName": "000089 - Disclosure - Risk/Return Detail Data {Elements} - Janus Henderson Venture Fund (Class A C S I N T Shares)", "role": "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "shortName": "Risk/Return Detail Data- Janus Henderson Venture Fund (Class A C S I N T Shares)", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000010488", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unique": true, "unitRef": null, "xsiNil": "false" } }, "S1": { "firstAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "true", "longName": "000013095 - Disclosure - Document and Entity Information", "section": 0, "shortName": "Document and Entity Information", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "span", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "D_28Jan2022_28Jan2022", "decimals": null, "lang": "en-US", "name": "dei:EntityRegistrantName", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S10": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010464", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000066076 - Disclosure - Class D Shares, S000010464 [Member]", "section": 9, "shortName": "Class D Shares, S000010464 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010464", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S11": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010475", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000067055 - Disclosure - Class D Shares, S000010475 [Member]", "section": 10, "shortName": "Class D Shares, S000010475 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010475", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S12": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010490", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000067881 - Disclosure - Class D Shares, S000010490 [Member]", "section": 11, "shortName": "Class D Shares, S000010490 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010490", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S13": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000025893", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000068622 - Disclosure - Class D Shares, S000025893 [Member]", "section": 12, "shortName": "Class D Shares, S000025893 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000025893", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S14": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010467", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000069416 - Disclosure - Class D Shares, S000010467 [Member]", "section": 13, "shortName": "Class D Shares, S000010467 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010467", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S15": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010470", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000070178 - Disclosure - Class D Shares, S000010470 [Member]", "section": 14, "shortName": "Class D Shares, S000010470 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010470", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S16": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010485", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000070946 - Disclosure - Class D Shares, S000010485 [Member]", "section": 15, "shortName": "Class D Shares, S000010485 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010485", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S17": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010488", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000071741 - Disclosure - Class D Shares, S000010488 [Member]", "section": 16, "shortName": "Class D Shares, S000010488 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010488", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S18": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000033204", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000080927 - Disclosure - Class A C S I N T Shares, S000033204 [Member]", "section": 17, "shortName": "Class A C S I N T Shares, S000033204 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000033204", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S19": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000057600", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000083342 - Disclosure - Class A C S I N T Shares, S000057600 [Member]", "section": 18, "shortName": "Class A C S I N T Shares, S000057600 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000057600", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S2": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010464", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000013935 - Disclosure - Class A C S I N R T Shares, S000010464 [Member]", "section": 1, "shortName": "Class A C S I N R T Shares, S000010464 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010464", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S20": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000057603", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000085648 - Disclosure - Class A C S I N T Shares, S000057603 [Member]", "section": 19, "shortName": "Class A C S I N T Shares, S000057603 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000057603", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S21": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000057602", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000087923 - Disclosure - Class A C S I N T Shares, S000057602 [Member]", "section": 20, "shortName": "Class A C S I N T Shares, S000057602 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000057602", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S22": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000010494", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000090275 - Disclosure - Class A C S I N T Shares, S000010494 [Member]", "section": 21, "shortName": "Class A C S I N T Shares, S000010494 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000010494", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S23": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000025889", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000092554 - Disclosure - Class A C S I N T Shares, S000025889 [Member]", "section": 22, "shortName": "Class A C S I N T Shares, S000025889 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000025889", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S24": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010489", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000094811 - Disclosure - Class A C S I N R T Shares, S000010489 [Member]", "section": 23, "shortName": "Class A C S I N R T Shares, S000010489 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010489", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S25": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010474", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000097365 - Disclosure - Class A C S I N R T Shares, S000010474 [Member]", "section": 24, "shortName": "Class A C S I N R T Shares, S000010474 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010474", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S26": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000068819", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000099852 - Disclosure - Class A C S I N R T Shares, S000068819 [Member]", "section": 25, "shortName": "Class A C S I N R T Shares, S000068819 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000068819", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S27": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000010465", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000102176 - Disclosure - Class A C S I N T Shares, S000010465 [Member]", "section": 26, "shortName": "Class A C S I N T Shares, S000010465 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000010465", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S28": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000057601", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000104475 - Disclosure - Class A C S I N R T Shares, S000057601 [Member]", "section": 27, "shortName": "Class A C S I N R T Shares, S000057601 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000057601", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S29": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010476", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000106972 - Disclosure - Class A C S I N R T Shares, S000010476 [Member]", "section": 28, "shortName": "Class A C S I N R T Shares, S000010476 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010476", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S3": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010475", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000016771 - Disclosure - Class A C S I N R T Shares, S000010475 [Member]", "section": 2, "shortName": "Class A C S I N R T Shares, S000010475 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010475", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S30": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000033204", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000155689 - Disclosure - Class D Shares, S000033204 [Member]", "section": 29, "shortName": "Class D Shares, S000033204 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000033204", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S31": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000057600", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000156582 - Disclosure - Class D Shares, S000057600 [Member]", "section": 30, "shortName": "Class D Shares, S000057600 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000057600", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S32": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000057603", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000157468 - Disclosure - Class D Shares, S000057603 [Member]", "section": 31, "shortName": "Class D Shares, S000057603 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000057603", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S33": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000057602", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000158306 - Disclosure - Class D Shares, S000057602 [Member]", "section": 32, "shortName": "Class D Shares, S000057602 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000057602", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S34": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010494", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000159180 - Disclosure - Class D Shares, S000010494 [Member]", "section": 33, "shortName": "Class D Shares, S000010494 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010494", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S35": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000025889", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000160000 - Disclosure - Class D Shares, S000025889 [Member]", "section": 34, "shortName": "Class D Shares, S000025889 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000025889", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S36": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010489", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000160807 - Disclosure - Class D Shares, S000010489 [Member]", "section": 35, "shortName": "Class D Shares, S000010489 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010489", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S37": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010474", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000161632 - Disclosure - Class D Shares, S000010474 [Member]", "section": 36, "shortName": "Class D Shares, S000010474 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010474", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S38": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000068819", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000162427 - Disclosure - Class D Shares, S000068819 [Member]", "section": 37, "shortName": "Class D Shares, S000068819 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000068819", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S39": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010465", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000163338 - Disclosure - Class D Shares, S000010465 [Member]", "section": 38, "shortName": "Class D Shares, S000010465 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010465", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S4": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010490", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000019273 - Disclosure - Class A C S I N R T Shares, S000010490 [Member]", "section": 3, "shortName": "Class A C S I N R T Shares, S000010490 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010490", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S40": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000057601", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000164173 - Disclosure - Class D Shares, S000057601 [Member]", "section": 39, "shortName": "Class D Shares, S000057601 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000057601", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S41": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010476", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000164999 - Disclosure - Class D Shares, S000010476 [Member]", "section": 40, "shortName": "Class D Shares, S000010476 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassDSharesMember_S000010476", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S5": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000025893", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000021563 - Disclosure - Class A C S I N R T Shares, S000025893 [Member]", "section": 4, "shortName": "Class A C S I N R T Shares, S000025893 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000025893", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S6": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010467", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000024073 - Disclosure - Class A C S I N R T Shares, S000010467 [Member]", "section": 5, "shortName": "Class A C S I N R T Shares, S000010467 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010467", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S7": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010470", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000026375 - Disclosure - Class A C S I N R T Shares, S000010470 [Member]", "section": 6, "shortName": "Class A C S I N R T Shares, S000010470 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010470", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S8": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010485", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000028954 - Disclosure - Class A C S I N R T Shares, S000010485 [Member]", "section": 7, "shortName": "Class A C S I N R T Shares, S000010485 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINRTSharesMember_S000010485", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } }, "S9": { "firstAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000010488", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" }, "groupType": "RR_Summaries", "isDefault": "false", "longName": "000031417 - Disclosure - Class A C S I N T Shares, S000010488 [Member]", "section": 8, "shortName": "Class A C S I N T Shares, S000010488 [Member]", "subGroupType": "", "uniqueAnchor": { "ancestors": [ "div", "div", "div", "div", "div", "div", "body", "html" ], "baseRef": "d175612d485bpos.htm", "contextRef": "ClassACSINTSharesMember_S000010488", "decimals": null, "lang": "en-US", "name": "rr:RiskReturnHeading", "reportCount": 1, "unitRef": null, "xsiNil": "false" } } }, "segmentCount": 198, "tag": { "dei_AmendmentDescription": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Description of changes contained within amended document.", "label": "Amendment Description" } } }, "localname": "AmendmentDescription", "nsuri": "http://xbrl.sec.gov/dei/2021", "presentation": [ "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "stringItemType" }, "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/2021", "presentation": [ "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "booleanItemType" }, "dei_DocumentCreationDate": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "The date the document was made available and submitted, in YYYY-MM-DD format. The date of submission, date of acceptance by the recipient, and the document effective date are all potentially different.", "label": "Document Creation Date", "verboseLabel": "Document Created Date" } } }, "localname": "DocumentCreationDate", "nsuri": "http://xbrl.sec.gov/dei/2021", "presentation": [ "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements", "http://xbrl.sec.gov/rr/role/RiskReturnDetailData" ], "xbrltype": "dateItemType" }, "dei_DocumentDomain": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Type of the document as assigned by the filer, corresponding to SEC document naming convention standards.", "label": "Prospectus" } } }, "localname": "DocumentDomain", "nsuri": "http://xbrl.sec.gov/dei/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "domainItemType" }, "dei_DocumentEffectiveDate": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "The date when a document, upon receipt and acceptance, becomes officially effective, in YYYY-MM-DD format. Usually it is a system-assigned date time value, but it may be declared by the submitter in some cases.", "label": "Document Effective Date" } } }, "localname": "DocumentEffectiveDate", "nsuri": "http://xbrl.sec.gov/dei/2021", "presentation": [ "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "dateItemType" }, "dei_DocumentInformationDocumentAxis": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "The axis of a table defines the relationship between the domain members or categories in the table and the line items or concepts that complete the table.", "label": "Document [Axis]" } } }, "localname": "DocumentInformationDocumentAxis", "nsuri": "http://xbrl.sec.gov/dei/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "dei_DocumentPeriodEndDate": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.", "label": "Document Period End Date", "verboseLabel": "Period End Date" } } }, "localname": "DocumentPeriodEndDate", "nsuri": "http://xbrl.sec.gov/dei/2021", "presentation": [ "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "dateItemType" }, "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/2021", "presentation": [ "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "submissionTypeItemType" }, "dei_EntityCentralIndexKey": { "auth_ref": [ "r78" ], "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", "verboseLabel": "CIK" } } }, "localname": "EntityCentralIndexKey", "nsuri": "http://xbrl.sec.gov/dei/2021", "presentation": [ "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "centralIndexKeyItemType" }, "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": "Series" } } }, "localname": "EntityDomain", "nsuri": "http://xbrl.sec.gov/dei/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "dei_EntityInvCompanyType": { "auth_ref": [ "r79" ], "lang": { "en-us": { "role": { "documentation": "One of: N-1A (Mutual Fund), N-1 (Open-End Separate Account with No Variable Annuities), N-2 (Closed-End Investment Company), N-3 (Separate Account Registered as Open-End Management Investment Company), N-4 (Variable Annuity UIT Separate Account), N-5 (Small Business Investment Company), N-6 (Variable Life UIT Separate Account), S-1 or S-3 (Face Amount Certificate Company), S-6 (UIT, Non-Insurance Product).", "label": "Entity Inv Company Type" } } }, "localname": "EntityInvCompanyType", "nsuri": "http://xbrl.sec.gov/dei/2021", "presentation": [ "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "invCompanyType" }, "dei_EntityRegistrantName": { "auth_ref": [ "r78" ], "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": "Registrant Name" } } }, "localname": "EntityRegistrantName", "nsuri": "http://xbrl.sec.gov/dei/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements", "http://xbrl.sec.gov/rr/role/RiskReturnDetailData" ], "xbrltype": "normalizedStringItemType" }, "dei_LegalEntityAxis": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "The set of legal entities associated with a report.", "label": "Series [Axis]" } } }, "localname": "LegalEntityAxis", "nsuri": "http://xbrl.sec.gov/dei/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "stringItemType" }, "dei_LegalEntityIdentifier": { "auth_ref": [ "r0" ], "lang": { "en-us": { "role": { "documentation": "A globally unique ISO 17442 value to identify entities, commonly abbreviated as LEI.", "label": "Legal Entity Identifier" } } }, "localname": "LegalEntityIdentifier", "nsuri": "http://xbrl.sec.gov/dei/2021", "presentation": [ "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "legalEntityIdentifierItemType" }, "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/2021", "presentation": [ "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "tradingSymbolItemType" }, "jif_BalancedIndexMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Balanced Index Member", "label": "Balanced Index [Member]", "verboseLabel": "Balanced Index\u00a0(reflects no deduction for expenses, fees, or taxes)" } } }, "localname": "BalancedIndexMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_BloombergUSAggregateBondIndexMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Bloomberg U S Aggregate Bond Index Member", "label": "Bloomberg U S Aggregate Bond Index [Member]", "verboseLabel": "Bloomberg U.S. Aggregate Bond Index\u00a0(reflects no deduction for expenses, fees, or taxes)" } } }, "localname": "BloombergUSAggregateBondIndexMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_C000028918Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000028918 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000028918Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000028919Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000028919 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000028919Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000028923Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000028923 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000028923Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000028926Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000028926 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000028926Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000028933Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000028933 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000028933Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000028934Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000028934 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000028934Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000028935Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000028935 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000028935Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000028947Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000028947 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000028947Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000028950Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000028950 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000028950Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000028951Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000028951 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000028951Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000028952Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000028952 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000028952Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000028956Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000028956 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000028956Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077597Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000077597 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000077597Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077598Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000077598 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000077598Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077599Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000077599 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000077599Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077600Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000077600 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000077600Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077601Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000077601 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000077601Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077618Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000077618 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000077618Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077619Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000077619 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000077619Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077620Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000077620 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000077620Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077621Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class R", "label": "C000077621 [Member]", "verboseLabel": "Class R" } } }, "localname": "C000077621Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077622Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000077622 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000077622Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077623Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000077623 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000077623Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077650Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000077650 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000077650Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077651Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000077651 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000077651Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077652Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000077652 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000077652Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077653Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class R", "label": "C000077653 [Member]", "verboseLabel": "Class R" } } }, "localname": "C000077653Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077654Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000077654 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000077654Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077655Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000077655 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000077655Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077656Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000077656 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000077656Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077657Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000077657 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000077657Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077658Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000077658 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000077658Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077659Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000077659 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000077659Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077660Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000077660 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000077660Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077661Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000077661 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000077661Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077662Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class R", "label": "C000077662 [Member]", "verboseLabel": "Class R" } } }, "localname": "C000077662Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077663Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000077663 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000077663Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077669Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000077669 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000077669Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077670Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000077670 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000077670Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077671Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000077671 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000077671Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077672Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000077672 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000077672Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077678Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000077678 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000077678Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077679Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000077679 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000077679Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077680Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000077680 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000077680Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077681Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class R", "label": "C000077681 [Member]", "verboseLabel": "Class R" } } }, "localname": "C000077681Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077682Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000077682 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000077682Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077683Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000077683 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000077683Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077684Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000077684 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000077684Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077685Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000077685 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000077685Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077686Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class R", "label": "C000077686 [Member]", "verboseLabel": "Class R" } } }, "localname": "C000077686Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077687Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000077687 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000077687Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077688Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000077688 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000077688Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077689Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000077689 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000077689Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077690Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000077690 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000077690Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077691Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class R", "label": "C000077691 [Member]", "verboseLabel": "Class R" } } }, "localname": "C000077691Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077692Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000077692 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000077692Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077722Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000077722 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000077722Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077723Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000077723 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000077723Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077724Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000077724 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000077724Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077725Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class R", "label": "C000077725 [Member]", "verboseLabel": "Class R" } } }, "localname": "C000077725Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077726Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000077726 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000077726Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077732Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000077732 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000077732Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077733Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000077733 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000077733Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077734Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000077734 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000077734Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077735Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class R", "label": "C000077735 [Member]", "verboseLabel": "Class R" } } }, "localname": "C000077735Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077736Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000077736 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000077736Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077737Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000077737 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000077737Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077738Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000077738 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000077738Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077739Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000077739 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000077739Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077740Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class R", "label": "C000077740 [Member]", "verboseLabel": "Class R" } } }, "localname": "C000077740Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077741Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000077741 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000077741Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077752Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000077752 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000077752Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077753Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000077753 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000077753Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077754Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000077754 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000077754Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000077755Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000077755 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000077755Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000083512Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000083512 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000083512Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000083513Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000083513 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000083513Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000083515Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000083515 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000083515Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000083517Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000083517 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000083517Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000083520Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000083520 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000083520Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000083521Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000083521 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000083521Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000083522Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000083522 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000083522Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000083530Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000083530 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000083530Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000083533Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000083533 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000083533Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000083534Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000083534 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000083534Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000083535Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000083535 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000083535Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000083538Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000083538 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000083538Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000083540Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000083540 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000083540Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000100475Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000100475 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000100475Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000100476Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000100476 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000100476Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000100477Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000100477 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000100477Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000100478Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000100478 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000100478Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000102172Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000102172 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000102172Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000102173Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000102173 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000102173Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000102174Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000102174 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000102174Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000102175Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000102175 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000102175Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000102176Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000102176 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000102176Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000102177Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000102177 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000102177Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000114869Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000114869 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000114869Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000114870Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000114870 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000114870Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000114872Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000114872 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000114872Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000114874Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000114874 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000114874Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000114875Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000114875 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000114875Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000114876Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000114876 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000114876Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000114880Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000114880 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000114880Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000114881Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000114881 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000114881Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000114882Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000114882 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000114882Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000114883Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000114883 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000114883Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000114888Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000114888 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000114888Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000177052Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000177052 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000177052Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000177053Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class R", "label": "C000177053 [Member]", "verboseLabel": "Class R" } } }, "localname": "C000177053Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000177054Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000177054 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000177054Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183873Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000183873 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000183873Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183875Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000183875 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000183875Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183876Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000183876 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000183876Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183877Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000183877 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000183877Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183878Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000183878 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000183878Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183880Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000183880 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000183880Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183881Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000183881 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000183881Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183883Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000183883 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000183883Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183884Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000183884 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000183884Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183885Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000183885 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000183885Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183886Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000183886 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000183886Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183887Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000183887 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000183887Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183888Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class R", "label": "C000183888 [Member]", "verboseLabel": "Class R" } } }, "localname": "C000183888Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183889Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000183889 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000183889Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183890Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000183890 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000183890Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183893Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000183893 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000183893Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183894Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000183894 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000183894Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183895Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000183895 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000183895Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183896Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000183896 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000183896Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183897Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000183897 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000183897Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183899Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000183899 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000183899Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183900Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000183900 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000183900Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183903Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000183903 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000183903Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183904Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000183904 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000183904Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183905Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000183905 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000183905Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183906Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000183906 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000183906Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183907Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000183907 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000183907Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183909Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000183909 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000183909Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000183910Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000183910 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000183910Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000198286Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000198286 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000198286Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000198287Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000198287 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000198287Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000198288Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000198288 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000198288Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000219906Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class S", "label": "C000219906 [Member]", "verboseLabel": "Class S" } } }, "localname": "C000219906Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000219907Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class T", "label": "C000219907 [Member]", "verboseLabel": "Class T" } } }, "localname": "C000219907Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000219908Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class N", "label": "C000219908 [Member]", "verboseLabel": "Class N" } } }, "localname": "C000219908Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000219909Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class A", "label": "C000219909 [Member]", "verboseLabel": "Class A" } } }, "localname": "C000219909Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000219910Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D", "label": "C000219910 [Member]", "verboseLabel": "Class D" } } }, "localname": "C000219910Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000219911Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class C", "label": "C000219911 [Member]", "verboseLabel": "Class C" } } }, "localname": "C000219911Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000219912Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class I", "label": "C000219912 [Member]", "verboseLabel": "Class I" } } }, "localname": "C000219912Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C000225293Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class R", "label": "C000225293 [Member]", "verboseLabel": "Class R" } } }, "localname": "C000225293Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_C85MSCIACWIexUSHighDivYld15MSCIUSAHighDivYldIndexMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "C8 Five M S C I A C W Iex U S High Div Yld One Five M S C I U S A High Div Yld Index Member", "label": "C8 Five M S C I A C W Iex U S High Div Yld One Five M S C I U S A High Div Yld Index [Member]", "verboseLabel": "85% MSCI ACWI ex-US High Div Yld/15% MSCI USA High Div Yld Index\u00a0(reflects no deduction for expenses, fees, or taxes, except\u00a0foreign withholding taxes)" } } }, "localname": "C85MSCIACWIexUSHighDivYld15MSCIUSAHighDivYldIndexMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_ClassACSINRTSharesMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class ACSINRT Shares [Member]", "label": "Class ACSINRT Shares [Member]", "terseLabel": "Class A C S I N R T Shares", "verboseLabel": "Class A C S I N R T Shares" } } }, "localname": "ClassACSINRTSharesMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares" ], "xbrltype": "domainItemType" }, "jif_ClassACSINTSharesMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class ACSINT Shares [Member]", "label": "Class ACSINT Shares [Member]", "terseLabel": "Class A C S I N T Shares", "verboseLabel": "Class A C S I N T Shares" } } }, "localname": "ClassACSINTSharesMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares" ], "xbrltype": "domainItemType" }, "jif_ClassDSharesMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Class D Shares [Member]", "label": "Class D Shares [Member]", "terseLabel": "Class D Shares", "verboseLabel": "Class D Shares" } } }, "localname": "ClassDSharesMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_FTSEEPRANareitGlobalIndexMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "F T S E E P R A Nareit Global Index Member", "label": "F T S E E P R A Nareit Global Index [Member]", "verboseLabel": "FTSE EPRA Nareit Global Index\u00a0(reflects no deduction for expenses, fees, or taxes)" } } }, "localname": "FTSEEPRANareitGlobalIndexMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_FTSEEPRANareitGlobalNetIndexMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "F T S E E P R A Nareit Global Net Index Member", "label": "F T S E E P R A Nareit Global Net Index [Member]", "verboseLabel": "FTSE EPRA Nareit Global Net Index\u00a0(reflects no deduction for expenses, fees, or taxes, except\u00a0foreign withholding taxes)" } } }, "localname": "FTSEEPRANareitGlobalNetIndexMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_MSCIAllCountryAsiaPacificexJapanIndexMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "M S C I All Country Asia Pacificex Japan Index Member", "label": "M S C I All Country Asia Pacificex Japan Index [Member]", "verboseLabel": "MSCI All Country Asia-Pacific ex-Japan Index\u00a0(reflects no deduction for expenses, fees, or taxes, except\u00a0foreign withholding taxes)" } } }, "localname": "MSCIAllCountryAsiaPacificexJapanIndexMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_MSCIAllCountryAsiaexJapanIndexMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "M S C I All Country Asiaex Japan Index Member", "label": "M S C I All Country Asiaex Japan Index [Member]", "verboseLabel": "MSCI All Country Asia ex-Japan Index\u00a0(reflects no deduction for expenses, fees, or taxes, except foreign withholding taxes)" } } }, "localname": "MSCIAllCountryAsiaexJapanIndexMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_MSCIAllCountryWorldIndexSMMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "M S C I All Country World Index S M Member", "label": "M S C I All Country World Index S M [Member]", "terseLabel": "MSCI All Country World Index\u00a0(reflects no deduction for expenses, fees, or taxes, except foreign withholding taxes)", "verboseLabel": "MSCI All Country World Index\u00a0(reflects no deduction for expenses, fees, or taxes, except\u00a0foreign withholding taxes)" } } }, "localname": "MSCIAllCountryWorldIndexSMMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_MSCIAllCountryWorldInformationTechnologyIndexSMMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "M S C I All Country World Information Technology Index S M Member", "label": "M S C I All Country World Information Technology Index S M [Member]", "verboseLabel": "MSCI All Country World Information Technology Index\u00a0(reflects no deduction for expenses, fees, or taxes, except\u00a0foreign withholding taxes)" } } }, "localname": "MSCIAllCountryWorldInformationTechnologyIndexSMMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_MSCIAllCountryWorldexUSAIndexSMMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "M S C I All Country Worldex U S A Index S M Member", "label": "M S C I All Country Worldex U S A Index S M [Member]", "verboseLabel": "MSCI All Country World ex-USA Index\u00a0(reflects no deduction for expenses, fees, or taxes, except foreign withholding taxes)" } } }, "localname": "MSCIAllCountryWorldexUSAIndexSMMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_MSCIEmergingMarketsIndexMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "M S C I Emerging Markets Index Member", "label": "M S C I Emerging Markets Index [Member]", "verboseLabel": "MSCI Emerging Markets Index\u00a0(reflects no deduction for expenses, fees, or taxes, except foreign withholding taxes)" } } }, "localname": "MSCIEmergingMarketsIndexMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_MSCIEuropeIndexSMMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "M S C I Europe Index S M Member", "label": "M S C I Europe Index S M [Member]", "verboseLabel": "MSCI Europe Index\u00a0(reflects no deduction for expenses, fees, or taxes, except foreign withholding taxes)" } } }, "localname": "MSCIEuropeIndexSMMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_MSCIWorldHealthCareIndexSMMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "M S C I World Health Care Index S M Member", "label": "M S C I World Health Care Index S M [Member]", "terseLabel": "MSCI World Health Care Index\u00a0(reflects no deduction for expenses, fees, or taxes, except\u00a0foreign withholding taxes)", "verboseLabel": "MSCI World Health Care Index\u00a0(reflects no deduction for expenses, fees, or taxes, except foreign withholding taxes)" } } }, "localname": "MSCIWorldHealthCareIndexSMMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_MSCIWorldIndexSMMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "M S C I World Index S M Member", "label": "M S C I World Index S M [Member]", "verboseLabel": "MSCI World Index\u00a0(reflects no deduction for expenses, fees, or taxes, except foreign withholding taxes)" } } }, "localname": "MSCIWorldIndexSMMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_ReturnAfterTaxesonDistributionsMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Return After Taxeson Distributions Member", "label": "Return After Taxeson Distributions [Member]", "verboseLabel": "Return After Taxes on Distributions" } } }, "localname": "ReturnAfterTaxesonDistributionsMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_ReturnAfterTaxesonDistributionsandSaleofFundSharesMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Return After Taxeson Distributionsand Saleof Fund Shares Member", "label": "Return After Taxeson Distributionsand Saleof Fund Shares [Member]", "verboseLabel": "Return After Taxes on Distributions and Sale of Fund Shares" } } }, "localname": "ReturnAfterTaxesonDistributionsandSaleofFundSharesMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_ReturnBeforeTaxesMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Return Before Taxes Member", "label": "Return Before Taxes [Member]", "verboseLabel": "Return Before Taxes" } } }, "localname": "ReturnBeforeTaxesMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_Russell1000GrowthIndexMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Russell One Thousand Growth Index Member", "label": "Russell One Thousand Growth Index [Member]", "verboseLabel": "Russell 1000\u00ae Growth Index\u00a0(reflects no deduction for expenses, fees, or taxes)" } } }, "localname": "Russell1000GrowthIndexMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_Russell2000GrowthIndexMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Russell Two Thousand Growth Index Member", "label": "Russell Two Thousand Growth Index [Member]", "verboseLabel": "Russell 2000\u00ae Growth Index\u00a0(reflects no deduction for expenses, fees, or taxes)" } } }, "localname": "Russell2000GrowthIndexMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_Russell2000IndexMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Russell Two Thousand Index Member", "label": "Russell Two Thousand Index [Member]", "verboseLabel": "Russell 2000\u00ae Index\u00a0(reflects no deduction for expenses, fees, or taxes)" } } }, "localname": "Russell2000IndexMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_Russell2500TMGrowthIndexMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Russell Two Five Hundred T M Growth Index Member", "label": "Russell Two Five Hundred T M Growth Index [Member]", "verboseLabel": "Russell 2500TM Growth Index\u00a0(reflects no deduction for expenses, fees, or taxes)" } } }, "localname": "Russell2500TMGrowthIndexMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_RussellMidcapGrowthIndexMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Russell Midcap Growth Index Member", "label": "Russell Midcap Growth Index [Member]", "verboseLabel": "Russell Midcap\u00ae Growth Index\u00a0(reflects no deduction for expenses, fees, or taxes)" } } }, "localname": "RussellMidcapGrowthIndexMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares" ], "xbrltype": "domainItemType" }, "jif_S000010464Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Balanced Fund Member", "label": "S000010464 [Member]", "verboseLabel": "Janus Henderson Balanced Fund" } } }, "localname": "S000010464Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000010465Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Global Technology and Innovation Fund Member", "label": "S000010465 [Member]", "verboseLabel": "Janus Henderson Global Technology and Innovation Fund" } } }, "localname": "S000010465Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000010467Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Growth and Income Fund Member", "label": "S000010467 [Member]", "verboseLabel": "Janus Henderson Growth and Income Fund" } } }, "localname": "S000010467Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000010470Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Research Fund Member", "label": "S000010470 [Member]", "verboseLabel": "Janus Henderson Research Fund" } } }, "localname": "S000010470Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000010474Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Global Select Fund Member", "label": "S000010474 [Member]", "verboseLabel": "Janus Henderson Global Select Fund" } } }, "localname": "S000010474Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000010475Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Contrarian Fund Member", "label": "S000010475 [Member]", "verboseLabel": "Janus Henderson Contrarian Fund" } } }, "localname": "S000010475Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000010476Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Overseas Fund Member", "label": "S000010476 [Member]", "verboseLabel": "Janus Henderson Overseas Fund" } } }, "localname": "S000010476Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000010485Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Triton Fund Member", "label": "S000010485 [Member]", "verboseLabel": "Janus Henderson Triton Fund" } } }, "localname": "S000010485Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000010488Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Venture Fund Member", "label": "S000010488 [Member]", "verboseLabel": "Janus Henderson Venture Fund" } } }, "localname": "S000010488Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000010489Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Global Research Fund Member", "label": "S000010489 [Member]", "verboseLabel": "Janus Henderson Global Research Fund" } } }, "localname": "S000010489Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000010490Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Enterprise Fund Member", "label": "S000010490 [Member]", "verboseLabel": "Janus Henderson Enterprise Fund" } } }, "localname": "S000010490Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000010494Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Global Life Sciences Fund Member", "label": "S000010494 [Member]", "verboseLabel": "Janus Henderson Global Life Sciences Fund" } } }, "localname": "S000010494Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000025889Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Global Real Estate Fund Member", "label": "S000025889 [Member]", "verboseLabel": "Janus Henderson Global Real Estate Fund" } } }, "localname": "S000025889Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000025893Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Forty Fund Member", "label": "S000025893 [Member]", "verboseLabel": "Janus Henderson Forty Fund" } } }, "localname": "S000025893Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000033204Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Asia Equity Fund Member", "label": "S000033204 [Member]", "verboseLabel": "Janus Henderson Asia Equity Fund" } } }, "localname": "S000033204Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000057600Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Emerging Markets Fund Member", "label": "S000057600 [Member]", "verboseLabel": "Janus Henderson Emerging Markets Fund" } } }, "localname": "S000057600Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000057601Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson International Opportunities Fund Member", "label": "S000057601 [Member]", "verboseLabel": "Janus Henderson International Opportunities Fund" } } }, "localname": "S000057601Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000057602Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Global Equity Income Fund Member", "label": "S000057602 [Member]", "verboseLabel": "Janus Henderson Global Equity Income Fund" } } }, "localname": "S000057602Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000057603Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson European Focus Fund Member", "label": "S000057603 [Member]", "verboseLabel": "Janus Henderson European Focus Fund" } } }, "localname": "S000057603Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_S000068819Member": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Janus Henderson Global Sustainable Equity Fund Member", "label": "S000068819 [Member]", "verboseLabel": "Janus Henderson Global Sustainable Equity Fund" } } }, "localname": "S000068819Member", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "jif_SP500IndexMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "S P Five Hundred Index Member", "label": "S P Five Hundred Index [Member]", "verboseLabel": "S&P 500\u00ae Index\u00a0(reflects no deduction for expenses, fees, or taxes)" } } }, "localname": "SP500IndexMember", "nsuri": "http://www.janushenderson.com/20220128", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares" ], "xbrltype": "domainItemType" }, "rr_AcquiredFundFeesAndExpensesBasedOnEstimates": { "auth_ref": [ "r29" ], "lang": { "en-us": { "role": { "documentation": "This element represents a statement that \"Acquired Fund\" (as defined) fees and expenses for the current year are based on estimates.", "label": "Acquired Fund Fees and Expenses, Based on Estimates [Text]" } } }, "localname": "AcquiredFundFeesAndExpensesBasedOnEstimates", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_AcquiredFundFeesAndExpensesOverAssets": { "auth_ref": [ "r38" ], "calculation": { "http://www.janushenderson.com/role/ScheduleAnnualFundOperatingExpenses000013": { "order": 50.0, "parentTag": "rr_ExpensesOverAssets", "weight": 1.0 } }, "lang": { "en-us": { "role": { "documentation": "Total Annual Fund Operating Expenses.", "label": "Acquired Fund Fees and Expenses" } } }, "localname": "AcquiredFundFeesAndExpensesOverAssets", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_AfterTaxesOnDistributionsAndSalesMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Calculate the taxes due on any distributions by the Fund by applying the tax rates specified in Instruction 4 to each component of the distributions on the reinvestment date (e.g., ordinary income, short-term capital gain, long-term capital gain). The taxable amount and tax character of each distribution should be as specified by the Fund on the dividend declaration date, but may be adjusted to reflect subsequent recharacterizations of distributions. Distributions should be adjusted to reflect the federal tax impact the distribution would have on an individual taxpayer on the reinvestment date. For example, assume no taxes are due on the portion of any distribution that would not result in federal income tax on an individual, e.g., tax-exempt interest or non-taxable returns of capital. The effect of applicable tax credits, such as the foreign tax credit, should be taken into account in accordance with federal tax law.", "label": "After Taxes on Distributions and Sales" } } }, "localname": "AfterTaxesOnDistributionsAndSalesMember", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "domainItemType" }, "rr_AfterTaxesOnDistributionsMember": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Calculate the taxes due on any distributions by the Fund by applying the tax rates specified in Instruction 4 to each component of the distributions on the reinvestment date (e.g., ordinary income, short-term capital gain, long-term capital gain). The taxable amount and tax character of each distribution should be as specified by the Fund on the dividend declaration date, but may be adjusted to reflect subsequent recharacterizations of distributions. Distributions should be adjusted to reflect the federal tax impact the distribution would have on an individual taxpayer on the reinvestment date. For example, assume no taxes are due on the portion of any distribution that would not result in federal income tax on an individual, e.g., tax-exempt interest or non-taxable returns of capital. The effect of applicable tax credits, such as the foreign tax credit, should be taken into account in accordance with federal tax law.", "label": "After Taxes on Distributions" } } }, "localname": "AfterTaxesOnDistributionsMember", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "domainItemType" }, "rr_AnnualReturn1990": { "auth_ref": [ "r68" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 1990" } } }, "localname": "AnnualReturn1990", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn1991": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 1991" } } }, "localname": "AnnualReturn1991", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn1992": { "auth_ref": [ "r68" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 1992" } } }, "localname": "AnnualReturn1992", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn1993": { "auth_ref": [ "r68" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 1993" } } }, "localname": "AnnualReturn1993", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn1994": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 1994" } } }, "localname": "AnnualReturn1994", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn1995": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 1995" } } }, "localname": "AnnualReturn1995", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn1996": { "auth_ref": [ "r68" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 1996" } } }, "localname": "AnnualReturn1996", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn1997": { "auth_ref": [ "r68" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 1997" } } }, "localname": "AnnualReturn1997", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn1998": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 1998" } } }, "localname": "AnnualReturn1998", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn1999": { "auth_ref": [ "r68" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 1999" } } }, "localname": "AnnualReturn1999", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2000": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2000" } } }, "localname": "AnnualReturn2000", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2001": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2001" } } }, "localname": "AnnualReturn2001", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2002": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2002" } } }, "localname": "AnnualReturn2002", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2003": { "auth_ref": [ "r68" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2003" } } }, "localname": "AnnualReturn2003", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2004": { "auth_ref": [ "r68" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2004" } } }, "localname": "AnnualReturn2004", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2005": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2005" } } }, "localname": "AnnualReturn2005", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2006": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2006" } } }, "localname": "AnnualReturn2006", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2007": { "auth_ref": [ "r68" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2007" } } }, "localname": "AnnualReturn2007", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2008": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2008" } } }, "localname": "AnnualReturn2008", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2009": { "auth_ref": [ "r68" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2009" } } }, "localname": "AnnualReturn2009", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2010": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2010" } } }, "localname": "AnnualReturn2010", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2011": { "auth_ref": [ "r68" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2011" } } }, "localname": "AnnualReturn2011", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2012": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2012", "verboseLabel": "2012" } } }, "localname": "AnnualReturn2012", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2013": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2013", "verboseLabel": "2013" } } }, "localname": "AnnualReturn2013", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2014": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2014", "verboseLabel": "2014" } } }, "localname": "AnnualReturn2014", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2015": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2015", "verboseLabel": "2015" } } }, "localname": "AnnualReturn2015", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2016": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2016", "verboseLabel": "2016" } } }, "localname": "AnnualReturn2016", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2017": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2017", "verboseLabel": "2017" } } }, "localname": "AnnualReturn2017", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2018": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2018", "verboseLabel": "2018" } } }, "localname": "AnnualReturn2018", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2019": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2019", "verboseLabel": "2019" } } }, "localname": "AnnualReturn2019", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2020": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2020", "verboseLabel": "2020" } } }, "localname": "AnnualReturn2020", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2021": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2021", "verboseLabel": "2021" } } }, "localname": "AnnualReturn2021", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2022": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2022" } } }, "localname": "AnnualReturn2022", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2023": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2023" } } }, "localname": "AnnualReturn2023", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2024": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2024" } } }, "localname": "AnnualReturn2024", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturn2025": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).", "label": "Annual Return 2025" } } }, "localname": "AnnualReturn2025", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AnnualReturnCaption": { "auth_ref": [ "r69" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. Provide annual total returns beginning with the earliest calendar year. Calculate annual returns using the Instructions to Item 8(a), except that the calculations should be based on calendar years. If a Fund's shares are sold subject to a sales load or account fees, state that sales loads or account fees are not reflected in the bar chart and that, if these amounts were reflected, returns would be less than those shown. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets). When a Multiple Class Fund offering one or more Classes offers a new Class in a prospectus that does not offer the shares of any other Class, include the bar chart with annual total returns for any other existing Class for the first year that the Class is offered. Explain in a footnote that the returns are for a Class that is not offered in the prospectus that would have substantially similar annual returns because the shares are invested in the same portfolio of securities and the annual returns would differ only to the extent that the Classes do not have the same expenses. Include return information for the other Class reflected in the bar chart in the performance table.", "label": "Annual Return Caption [Text]", "terseLabel": "Caption" } } }, "localname": "AnnualReturnCaption", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_AnnualReturnColumnName": { "auth_ref": [ "r62" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. Provide annual total returns beginning with the earliest calendar year. Calculate annual returns using the Instructions to Item 8(a), except that the calculations should be based on calendar years. If a Fund's shares are sold subject to a sales load or account fees, state that sales loads or account fees are not reflected in the bar chart and that, if these amounts were reflected, returns would be less than those shown. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets). When a Multiple Class Fund offering one or more Classes offers a new Class in a prospectus that does not offer the shares of any other Class, include the bar chart with annual total returns for any other existing Class for the first year that the Class is offered. Explain in a footnote that the returns are for a Class that is not offered in the prospectus that would have substantially similar annual returns because the shares are invested in the same portfolio of securities and the annual returns would differ only to the extent that the Classes do not have the same expenses. Include return information for the other Class reflected in the bar chart in the performance table.", "label": "Annual Return, Column [Text]", "terseLabel": "Column" } } }, "localname": "AnnualReturnColumnName", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_AnnualReturnInceptionDate": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. Provide annual total returns beginning with the earliest calendar year. Calculate annual returns using the Instructions to Item 8(a), except that the calculations should be based on calendar years. If a Fund's shares are sold subject to a sales load or account fees, state that sales loads or account fees are not reflected in the bar chart and that, if these amounts were reflected, returns would be less than those shown. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets). When a Multiple Class Fund offering one or more Classes offers a new Class in a prospectus that does not offer the shares of any other Class, include the bar chart with annual total returns for any other existing Class for the first year that the Class is offered. Explain in a footnote that the returns are for a Class that is not offered in the prospectus that would have substantially similar annual returns because the shares are invested in the same portfolio of securities and the annual returns would differ only to the extent that the Classes do not have the same expenses. Include return information for the other Class reflected in the bar chart in the performance table.", "label": "Annual Return, Inception Date", "terseLabel": "Inception Date" } } }, "localname": "AnnualReturnInceptionDate", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "dateItemType" }, "rr_AverageAnnualReturnCaption": { "auth_ref": [ "r73" ], "lang": { "en-us": { "role": { "documentation": "This item represents Average Annual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.", "label": "Average Annual Return, Caption" } } }, "localname": "AverageAnnualReturnCaption", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_AverageAnnualReturnColumnName": { "auth_ref": [ "r59" ], "lang": { "en-us": { "role": { "documentation": "This item represents Average Annual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.", "label": "Average Annual Return, Column Name" } } }, "localname": "AverageAnnualReturnColumnName", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_AverageAnnualReturnInceptionDate": { "auth_ref": [ "r72" ], "lang": { "en-us": { "role": { "documentation": "Return Before Taxes.", "label": "Inception Date" } } }, "localname": "AverageAnnualReturnInceptionDate", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "dateItemType" }, "rr_AverageAnnualReturnLabel": { "auth_ref": [ "r60" ], "lang": { "en-us": { "role": { "documentation": "This item represents Average Annual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.", "label": "Label" } } }, "localname": "AverageAnnualReturnLabel", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_AverageAnnualReturnSinceInception": { "auth_ref": [ "r60" ], "lang": { "en-us": { "role": { "documentation": "Return Before Taxes.", "label": "Since Inception" } } }, "localname": "AverageAnnualReturnSinceInception", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AverageAnnualReturnYear01": { "auth_ref": [ "r60" ], "lang": { "en-us": { "role": { "documentation": "Return Before Taxes.", "label": "1 Year" } } }, "localname": "AverageAnnualReturnYear01", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AverageAnnualReturnYear05": { "auth_ref": [ "r60" ], "lang": { "en-us": { "role": { "documentation": "Return Before Taxes.", "label": "5 Years" } } }, "localname": "AverageAnnualReturnYear05", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_AverageAnnualReturnYear10": { "auth_ref": [ "r60" ], "lang": { "en-us": { "role": { "documentation": "Return Before Taxes.", "label": "10 Years" } } }, "localname": "AverageAnnualReturnYear10", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_BarChartAndPerformanceTableHeading": { "auth_ref": [ "r55" ], "lang": { "en-us": { "role": { "documentation": "Risk/Return Bar Chart and Table.", "label": "Bar Chart and Performance Table [Heading]" } } }, "localname": "BarChartAndPerformanceTableHeading", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_BarChartClosingTextBlock": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.", "label": "Bar Chart Closing [Text Block]" } } }, "localname": "BarChartClosingTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_BarChartDoesNotReflectSalesLoads": { "auth_ref": [ "r56" ], "lang": { "en-us": { "role": { "documentation": "Include the bar chart and table required by Item 4 (b)(2)(ii) and (iii) of this section. Provide a brief explanation of how the information illustrates the variability of the Fund's returns (e.g., by stating that the information provides some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance). Provide a statement to the effect that the Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Provide annual total returns beginning with the earliest calendar year. Calculate annual returns using the Instructions to Item 8(a), except that the calculations should be based on calendar years. If a Fund's shares are sold subject to a sales load or account fees, state that sales loads or account fees are not reflected in the bar chart and that, if these amounts were reflected, returns would be less than those shown.", "label": "Bar Chart Does Not Reflect Sales Loads [Text]" } } }, "localname": "BarChartDoesNotReflectSalesLoads", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_BarChartFootnotesTextBlock": { "auth_ref": [ "r67" ], "lang": { "en-us": { "role": { "documentation": "Multiple Class Funds.", "label": "Bar Chart Footnotes [Text Block]" } } }, "localname": "BarChartFootnotesTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_BarChartHeading": { "auth_ref": [ "r55" ], "lang": { "en-us": { "role": { "documentation": "Risk/Return Bar Chart and Table.", "label": "Bar Chart [Heading]" } } }, "localname": "BarChartHeading", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_BarChartHighestQuarterlyReturn": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.", "label": "Highest Quarterly Return" } } }, "localname": "BarChartHighestQuarterlyReturn", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_BarChartHighestQuarterlyReturnDate": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.", "label": "Highest Quarterly Return, Date" } } }, "localname": "BarChartHighestQuarterlyReturnDate", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "dateItemType" }, "rr_BarChartLowestQuarterlyReturn": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.", "label": "Lowest Quarterly Return" } } }, "localname": "BarChartLowestQuarterlyReturn", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_BarChartLowestQuarterlyReturnDate": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.", "label": "Lowest Quarterly Return, Date" } } }, "localname": "BarChartLowestQuarterlyReturnDate", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "dateItemType" }, "rr_BarChartNarrativeTextBlock": { "auth_ref": [ "r56" ], "lang": { "en-us": { "role": { "documentation": "Provide a brief explanation of how the information illustrates the variability of the Fund's returns (e.g., by stating that the information provides some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance). Provide a statement to the effect that the Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.", "label": "Bar Chart Narrative [Text Block]" } } }, "localname": "BarChartNarrativeTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_BarChartReasonSelectedClassDifferentFromImmediatelyPrecedingPeriod": { "auth_ref": [ "r71" ], "lang": { "en-us": { "role": { "documentation": "If the Fund provides annual total returns in the bar chart for a Class that is different from the Class selected for the most immediately preceding period, explain in a footnote to the bar chart the reasons for the selection of a different Class.", "label": "Bar Chart, Reason Selected Class Different from Immediately Preceding Period [Text]" } } }, "localname": "BarChartReasonSelectedClassDifferentFromImmediatelyPrecedingPeriod", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_BarChartReturnsForClassNotOfferedInProspectus": { "auth_ref": [ "r69" ], "lang": { "en-us": { "role": { "documentation": "When a Multiple Class Fund offering one or more Classes offers a new Class in a prospectus that does not offer the shares of any other Class, include the bar chart with annual total returns for any other existing Class for the first year that the Class is offered. Explain in a footnote that the returns are for a Class that is not offered in the prospectus that would have substantially similar annual returns because the shares are invested in the same portfolio of securities and the annual returns would differ only to the extent that the Classes do not have the same expenses. Include return information for the other Class reflected in the bar chart in the performance table.", "label": "Bar Chart, Returns for Class Not Offered in Prospectus [Text]" } } }, "localname": "BarChartReturnsForClassNotOfferedInProspectus", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_BarChartYearToDateReturn": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.", "label": "Bar Chart, Year to Date Return" } } }, "localname": "BarChartYearToDateReturn", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_BarChartYearToDateReturnDate": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.", "label": "Bar Chart, Year to Date Return, Date" } } }, "localname": "BarChartYearToDateReturnDate", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "dateItemType" }, "rr_Component1OtherExpensesOverAssets": { "auth_ref": [ "r25" ], "calculation": { "http://www.janushenderson.com/role/ScheduleAnnualFundOperatingExpenses000013": { "order": 10.0, "parentTag": "rr_OtherExpensesOverAssets", "weight": 1.0 } }, "lang": { "en-us": { "role": { "documentation": "The Fund may subdivide this caption into no more than three subcaptions that identify the largest expense or expenses comprising \"Other Expenses,\" but must include a total of all \"Other Expenses.\" Alternatively, the Fund may include the components of \"Other Expenses\" in a parenthetical to the caption.", "label": "Component1 Other Expenses" } } }, "localname": "Component1OtherExpensesOverAssets", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_Component2OtherExpensesOverAssets": { "auth_ref": [ "r37" ], "calculation": { "http://www.janushenderson.com/role/ScheduleAnnualFundOperatingExpenses000013": { "order": 20.0, "parentTag": "rr_OtherExpensesOverAssets", "weight": 1.0 } }, "lang": { "en-us": { "role": { "documentation": "The Fund may subdivide this caption into no more than three subcaptions that identify the largest expense or expenses comprising \"Other Expenses,\" but must include a total of all \"Other Expenses.\" Alternatively, the Fund may include the components of \"Other Expenses\" in a parenthetical to the caption.", "label": "Component2 Other Expenses" } } }, "localname": "Component2OtherExpensesOverAssets", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_Component3OtherExpensesOverAssets": { "auth_ref": [ "r25" ], "calculation": { "http://www.janushenderson.com/role/ScheduleAnnualFundOperatingExpenses000013": { "order": 30.0, "parentTag": "rr_OtherExpensesOverAssets", "weight": 1.0 } }, "lang": { "en-us": { "role": { "documentation": "The Fund may subdivide this caption into no more than three subcaptions that identify the largest expense or expenses comprising \"Other Expenses,\" but must include a total of all \"Other Expenses.\" Alternatively, the Fund may include the components of \"Other Expenses\" in a parenthetical to the caption.", "label": "Component3 Other Expenses" } } }, "localname": "Component3OtherExpensesOverAssets", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_CoregistrantAxis": { "auth_ref": [ "r2" ], "lang": { "en-us": { "role": { "documentation": "The Coregistrant Axis may be used to distinguish disclosures that belong to registrants having different Central Index Key (CIK) values that nevertheless all present in the same filing.", "label": "Coregistrant [Axis]" } } }, "localname": "CoregistrantAxis", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_CoregistrantDomain": { "auth_ref": [ "r3" ], "lang": { "en-us": { "role": { "documentation": "The default member of the Coregistrant axis. It represents any disclosure that applies to the registrant whose Central Index Key (CIK) is that of the default context.", "label": "Coregistrant [Domain]" } } }, "localname": "CoregistrantDomain", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "domainItemType" }, "rr_DistributionAndService12b1FeesOverAssets": { "auth_ref": [ "r44" ], "calculation": { "http://www.janushenderson.com/role/ScheduleAnnualFundOperatingExpenses000013": { "order": 20.0, "parentTag": "rr_ExpensesOverAssets", "weight": 1.0 } }, "lang": { "en-us": { "role": { "documentation": "Distribution [and/or Service] (12b-1) Fees\" include all distribution or other expenses incurred during the most recent fiscal year under a plan adopted pursuant to rule 12b-1 [17 CFR 270.12b-1]. Under an appropriate caption or a subcaption of \"Other Expenses,\" disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.", "label": "Distribution and Service (12b-1) Fees", "verboseLabel": "Distribution/Service (12b-1) Fees" } } }, "localname": "DistributionAndService12b1FeesOverAssets", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_DistributionOrSimilarNon12b1FeesOverAssets": { "auth_ref": [ "r22" ], "calculation": { "http://www.janushenderson.com/role/ScheduleAnnualFundOperatingExpenses000013": { "order": 30.0, "parentTag": "rr_ExpensesOverAssets", "weight": 1.0 } }, "lang": { "en-us": { "role": { "documentation": "Distribution [and/or Service] (12b-1) Fees\" include all distribution or other expenses incurred during the most recent fiscal year under a plan adopted pursuant to rule 12b-1 [17 CFR 270.12b-1]. Under an appropriate caption or a subcaption of \"Other Expenses,\" disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.", "label": "Distribution or Similar (Non 12b-1) Fees" } } }, "localname": "DistributionOrSimilarNon12b1FeesOverAssets", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_ExchangeFee": { "auth_ref": [ "r41" ], "lang": { "en-us": { "role": { "documentation": "Exchange Fee includes the maximum fee charged for any exchange or transfer of interest from the Fund to another fund. The Fund may include in a footnote to the table, if applicable, a tabular presentation of the range of exchange fees or a narrative explanation of the fees.", "label": "Exchange Fee" } } }, "localname": "ExchangeFee", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativeMonetaryType" }, "rr_ExchangeFeeOverRedemption": { "auth_ref": [ "r19" ], "lang": { "en-us": { "role": { "documentation": "Exchange Fee includes the maximum fee charged for any exchange or transfer of interest from the Fund to another fund. The Fund may include in a footnote to the table, if applicable, a tabular presentation of the range of exchange fees or a narrative explanation of the fees.", "label": "Exchange Fee (as a percentage of Amount Redeemed)" } } }, "localname": "ExchangeFeeOverRedemption", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_ExpenseBreakpointDiscounts": { "auth_ref": [ "r12" ], "lang": { "en-us": { "role": { "documentation": "Include the narrative explanations in the order indicated. A Fund may modify the narrative explanations if the explanation contains comparable information to that shown. The narrative explanation regarding sales charge discounts is only required by a Fund that offers such discounts and should specify the minimum level of investment required to qualify for a discount.", "label": "Expense Breakpoint Discounts [Text]" } } }, "localname": "ExpenseBreakpointDiscounts", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ExpenseBreakpointMinimumInvestmentRequiredAmount": { "auth_ref": [ "r12" ], "lang": { "en-us": { "role": { "documentation": "This element represents the minimum level of investment required to qualify for discounted sales charges or fund expenses (SEC Form N-1A 2006-09-14 A.3.instructions.1.b).", "label": "Expense Breakpoint, Minimum Investment Required [Amount]" } } }, "localname": "ExpenseBreakpointMinimumInvestmentRequiredAmount", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "monetaryItemType" }, "rr_ExpenseExampleByYearCaption": { "auth_ref": [ "r8" ], "lang": { "en-us": { "role": { "documentation": "The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.", "label": "Expense Example by, Year, Caption [Text]" } } }, "localname": "ExpenseExampleByYearCaption", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ExpenseExampleByYearHeading": { "auth_ref": [ "r8" ], "lang": { "en-us": { "role": { "documentation": "The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.", "label": "Expense Example by Year [Heading]" } } }, "localname": "ExpenseExampleByYearHeading", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ExpenseExampleClosingTextBlock": { "auth_ref": [ "r31" ], "lang": { "en-us": { "role": { "documentation": "The Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher.", "label": "Expense Example Closing [Text Block]" } } }, "localname": "ExpenseExampleClosingTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_ExpenseExampleFootnotesTextBlock": { "auth_ref": [ "r10" ], "lang": { "en-us": { "role": { "documentation": "The Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher.", "label": "Expense Example Footnotes [Text Block]" } } }, "localname": "ExpenseExampleFootnotesTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_ExpenseExampleHeading": { "auth_ref": [ "r31" ], "lang": { "en-us": { "role": { "documentation": "Heading for Expense Example.", "label": "Expense Example [Heading]" } } }, "localname": "ExpenseExampleHeading", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ExpenseExampleNarrativeTextBlock": { "auth_ref": [ "r7" ], "lang": { "en-us": { "role": { "documentation": "The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.", "label": "Expense Example Narrative [Text Block]" } } }, "localname": "ExpenseExampleNarrativeTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_ExpenseExampleNoRedemptionByYearCaption": { "auth_ref": [ "r9" ], "lang": { "en-us": { "role": { "documentation": "You would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.", "label": "Expense Example, No Redemption, By Year, Caption [Text]" } } }, "localname": "ExpenseExampleNoRedemptionByYearCaption", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ExpenseExampleNoRedemptionNarrativeTextBlock": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "Contains a command for the SEC Viewer for the role corresponding to ExpenseExampleNoRedemption.", "label": "Expense Example, No Redemption Narrative [Text Block]" } } }, "localname": "ExpenseExampleNoRedemptionNarrativeTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_ExpenseExampleNoRedemptionYear01": { "auth_ref": [ "r9" ], "lang": { "en-us": { "role": { "documentation": "You would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.", "label": "Expense Example, No Redemption, 1 Year", "terseLabel": "1 Year" } } }, "localname": "ExpenseExampleNoRedemptionYear01", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativeMonetaryType" }, "rr_ExpenseExampleNoRedemptionYear03": { "auth_ref": [ "r9" ], "lang": { "en-us": { "role": { "documentation": "You would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.", "label": "Expense Example, No Redemption, 3 Years", "terseLabel": "3 Years" } } }, "localname": "ExpenseExampleNoRedemptionYear03", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativeMonetaryType" }, "rr_ExpenseExampleNoRedemptionYear05": { "auth_ref": [ "r32" ], "lang": { "en-us": { "role": { "documentation": "You would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.", "label": "Expense Example, No Redemption, 5 Years", "terseLabel": "5 Years" } } }, "localname": "ExpenseExampleNoRedemptionYear05", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativeMonetaryType" }, "rr_ExpenseExampleNoRedemptionYear10": { "auth_ref": [ "r32" ], "lang": { "en-us": { "role": { "documentation": "You would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.", "label": "Expense Example, No Redemption, 10 Years", "terseLabel": "10 Years" } } }, "localname": "ExpenseExampleNoRedemptionYear10", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativeMonetaryType" }, "rr_ExpenseExampleYear01": { "auth_ref": [ "r31" ], "lang": { "en-us": { "role": { "documentation": "The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.", "label": "Expense Example, with Redemption, 1 Year", "terseLabel": "1 Year" } } }, "localname": "ExpenseExampleYear01", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativeMonetaryType" }, "rr_ExpenseExampleYear03": { "auth_ref": [ "r8" ], "lang": { "en-us": { "role": { "documentation": "The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.", "label": "Expense Example, with Redemption, 3 Years", "terseLabel": "3 Years" } } }, "localname": "ExpenseExampleYear03", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativeMonetaryType" }, "rr_ExpenseExampleYear05": { "auth_ref": [ "r8" ], "lang": { "en-us": { "role": { "documentation": "The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.", "label": "Expense Example, with Redemption, 5 Years", "terseLabel": "5 Years" } } }, "localname": "ExpenseExampleYear05", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativeMonetaryType" }, "rr_ExpenseExampleYear10": { "auth_ref": [ "r8" ], "lang": { "en-us": { "role": { "documentation": "The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.", "label": "Expense Example, with Redemption, 10 Years", "terseLabel": "10 Years" } } }, "localname": "ExpenseExampleYear10", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativeMonetaryType" }, "rr_ExpenseFootnotesTextBlock": { "auth_ref": [ "r16" ], "lang": { "en-us": { "role": { "documentation": "Shareholder Fees.", "label": "Expense Footnotes [Text Block]" } } }, "localname": "ExpenseFootnotesTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_ExpenseHeading": { "auth_ref": [ "r14" ], "lang": { "en-us": { "role": { "documentation": "Risk/Return Summary Fee Table Includes the following information, in plain English under rule 421(d) under the Securities Act, after Item 2 Fees and expenses of the Fund This table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Shareholder Fees (fees paid directly from your investment) Example This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be You would pay the following expenses if you did not redeem your shares The Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher. Portfolio Turnover The Fund pays transaction costs, such as commissions, when it buys and sells securities (or \"turns over\" its portfolio). A higher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was __% of the average value of its whole portfolio. Instructions. A.3.instructions.6 New Funds. For purposes of this Item, a \"New Fund\" is a Fund that does not include in Form N-1A financial statements reporting operating results or that includes financial statements for the Fund's initial fiscal year reporting operating results for a period of 6 months or less. The following Instructions apply to New Funds.", "label": "Expense [Heading]" } } }, "localname": "ExpenseHeading", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ExpenseNarrativeTextBlock": { "auth_ref": [ "r12" ], "lang": { "en-us": { "role": { "documentation": "This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[ ] in [name of fund family] funds. More information about these and other discounts is available from your financial intermediary and in [identify section heading and page number] of the Fund's prospectus and [identify section heading and page number] of the Fund's statement of additional information", "label": "Expense Narrative [Text Block]" } } }, "localname": "ExpenseNarrativeTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_ExpensesDeferredChargesTextBlock": { "auth_ref": [ "r17" ], "lang": { "en-us": { "role": { "documentation": "A Fund may include in a footnote to the table, if applicable, a tabular presentation showing the amount of deferred sales charges (loads) over time or a narrative explanation of the sales charges (loads) (e.g., __% in the first year after purchase, declining to __% in the __ year and eliminated thereafter).", "label": "Expenses Deferred Charges [Text Block]" } } }, "localname": "ExpensesDeferredChargesTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_ExpensesExplanationOfNonrecurringAccountFee": { "auth_ref": [ "r20" ], "lang": { "en-us": { "role": { "documentation": "The Fund may include an explanation of any non-recurring account fee in a parenthetical to the caption or in a footnote to the table.", "label": "Expenses Explanation of Nonrecurring Account Fee [Text]" } } }, "localname": "ExpensesExplanationOfNonrecurringAccountFee", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees": { "auth_ref": [ "r30" ], "lang": { "en-us": { "role": { "documentation": "The Fund may clarify in a footnote to the fee table that the total annual fund operating expenses under Item 3 do not correlate to the ratio of expenses to average net assets given in response to Item 8, which reflects the operating expenses of the Fund and does not include Acquired Fund fees and expenses.", "label": "Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]" } } }, "localname": "ExpensesNotCorrelatedToRatioDueToAcquiredFundFees", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ExpensesOtherExpensesHadExtraordinaryExpensesBeenIncluded": { "auth_ref": [ "r24" ], "lang": { "en-us": { "role": { "documentation": "\"Other Expenses\" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's \"Other Expenses,\" disclose in a footnote to the table what \"Other Expenses\" would have been had the extraordinary expenses been included.", "label": "Expenses Other Expenses Had Extraordinary Expenses Been Included [Text]" } } }, "localname": "ExpensesOtherExpensesHadExtraordinaryExpensesBeenIncluded", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ExpensesOverAssets": { "auth_ref": [ "r26" ], "calculation": { "http://www.janushenderson.com/role/ScheduleAnnualFundOperatingExpenses000013": { "order": 10.0, "parentTag": "rr_NetExpensesOverAssets", "weight": 1.0 } }, "lang": { "en-us": { "role": { "documentation": "Total Annual Fund Operating Expenses. If the Fund is a Feeder Fund, reflect the aggregate expenses of the Feeder Fund and the Master Fund in a single fee table using the captions provided. In a footnote to the fee table, state that the table and Example reflect the expenses of both the Feeder and Master Funds. If the prospectus offers more than one Class of a Multiple Class Fund or more than one Feeder Fund that invests in the same Master Fund, provide a separate response for each Class or Feeder Fund. Base the percentages of \"Annual Fund Operating Expenses\" on amounts incurred during the Fund's most recent fiscal year, but include in expenses amounts that would have been incurred absent expense reimbursement or fee waiver arrangements. If the Fund has changed its fiscal year and, as a result, the most recent fiscal year is less than three months, use the fiscal year prior to the most recent fiscal year as the basis for determining \"Annual Fund Operating Expenses.\"", "label": "Expenses (as a percentage of Assets)", "totalLabel": "Total Annual Fund Operating Expenses", "verboseLabel": "Total Annual Fund Operating Expenses" } } }, "localname": "ExpensesOverAssets", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_ExpensesRangeOfExchangeFeesTextBlock": { "auth_ref": [ "r19" ], "lang": { "en-us": { "role": { "documentation": "The Fund may include in a footnote to the table, if applicable, a tabular presentation of the range of exchange fees or a narrative explanation of the fees.", "label": "Expenses Range of Exchange Fees [Text Block]" } } }, "localname": "ExpensesRangeOfExchangeFeesTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_ExpensesRepresentBothMasterAndFeeder": { "auth_ref": [ "r15" ], "lang": { "en-us": { "role": { "documentation": "If the Fund is a Feeder Fund, reflect the aggregate expenses of the Feeder Fund and the Master Fund in a single fee table using the captions provided. In a footnote to the fee table, state that the table and Example reflect the expenses of both the Feeder and Master Funds.", "label": "Expenses Represent Both Master and Feeder [Text]" } } }, "localname": "ExpensesRepresentBothMasterAndFeeder", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ExpensesRestatedToReflectCurrent": { "auth_ref": [ "r27" ], "lang": { "en-us": { "role": { "documentation": "In a footnote to the table, disclose that the expense information in the table has been restated to reflect current fees.", "label": "Expenses Restated to Reflect Current [Text]" } } }, "localname": "ExpensesRestatedToReflectCurrent", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_FeeWaiverOrReimbursementOverAssets": { "auth_ref": [ "r38" ], "calculation": { "http://www.janushenderson.com/role/ScheduleAnnualFundOperatingExpenses000013": { "order": 20.0, "parentTag": "rr_NetExpensesOverAssets", "weight": 1.0 } }, "lang": { "en-us": { "role": { "documentation": "Total Annual Fund Operating Expenses. If there were expense reimbursement or fee waiver arrangements that reduced any Fund operating expenses and will continue to reduce them for no less than one year from the effective date of the Fund's registration statement, a Fund may add two captions to the table one caption showing the amount of the expense reimbursement or fee waiver, and a second caption showing the Fund's net expenses after subtracting the fee reimbursement or expense waiver from the total fund operating expenses. The Fund should place these additional captions directly below the \"Total Annual Fund Operating Expenses\" caption of the table and should use appropriate descriptive captions, such as \"Fee Waiver [and/or Expense Reimbursement]\" and \"Total Annual Fund Operating Expenses After Fee Waiver [and/or Expense Reimbursement],\" respectively. If the Fund provides this disclosure, also disclose the period for which the expense reimbursement or fee waiver arrangement is expected to continue, and briefly describe who can terminate the arrangement and under what circumstances.", "label": "Fee Waiver or Reimbursement", "negatedLabel": "Fee Waiver" } } }, "localname": "FeeWaiverOrReimbursementOverAssets", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonPositivePure4Type" }, "rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination": { "auth_ref": [ "r28" ], "lang": { "en-us": { "role": { "documentation": "This element represents the date of expected termination of any expense reimbursement or fee waiver arrangements that reduce any Fund operating expenses (SEC Form N-1A 2006-09-14 A.3.table.1.11 Total Annual Fund Operating Expenses A.3.instructions.3.e).", "label": "Fee Waiver or Reimbursement over Assets, Date of Termination" } } }, "localname": "FeeWaiverOrReimbursementOverAssetsDateOfTermination", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_HighestQuarterlyReturnLabel": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.", "label": "Highest Quarterly Return, Label" } } }, "localname": "HighestQuarterlyReturnLabel", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_IndexNoDeductionForFeesExpensesTaxes": { "auth_ref": [ "r61" ], "lang": { "en-us": { "role": { "documentation": "The Performance Table includes a parenthetical, indicating that the Index \"(reflects no deduction for fees, expenses or taxes)\". This tag is used when this is reflected in a footnote.", "label": "Index No Deduction for Fees, Expenses, Taxes [Text]" } } }, "localname": "IndexNoDeductionForFeesExpensesTaxes", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_LowestQuarterlyReturnLabel": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.", "label": "Lowest Quarterly Return, Label" } } }, "localname": "LowestQuarterlyReturnLabel", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ManagementFeesOverAssets": { "auth_ref": [ "r21" ], "calculation": { "http://www.janushenderson.com/role/ScheduleAnnualFundOperatingExpenses000013": { "order": 10.0, "parentTag": "rr_ExpensesOverAssets", "weight": 1.0 } }, "lang": { "en-us": { "role": { "documentation": "Management Fees include investment advisory fees (including any fees based on the Fund's performance), any other management fees payable to the investment adviser or its affiliates, and administrative fees payable to the investment adviser or its affiliates that are not included as \"Other Expenses.\"", "label": "Management Fees (as a percentage of Assets)", "verboseLabel": "Management Fees" } } }, "localname": "ManagementFeesOverAssets", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_MaximumAccountFee": { "auth_ref": [ "r13" ], "lang": { "en-us": { "role": { "documentation": "Include the caption \"Maximum Account Fees\" only if the Fund charges these fees. A Fund may omit other captions if the Fund does not charge the fees or expenses covered by the captions. Disclose account fees that may be charged to a typical investor in the Fund; fees that apply to only a limited number of shareholders based on their particular circumstances need not be disclosed. Include a caption describing the maximum account fee (e.g., \"Maximum Account Maintenance Fee\" or \"Maximum Cash Management Fee\"). State the maximum annual account fee as either a fixed dollar amount or a percentage of assets. Include in a parenthetical to the caption the basis on which any percentage is calculated. If an account fee is charged only to accounts that do not meet a certain threshold (e.g., accounts under $5)", "label": "Maximum Account Fee" } } }, "localname": "MaximumAccountFee", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativeMonetaryType" }, "rr_MaximumAccountFeeOverAssets": { "auth_ref": [ "r42" ], "lang": { "en-us": { "role": { "documentation": "Include the caption \"Maximum Account Fees\" only if the Fund charges these fees. A Fund may omit other captions if the Fund does not charge the fees or expenses covered by the captions. Disclose account fees that may be charged to a typical investor in the Fund; fees that apply to only a limited number of shareholders based on their particular circumstances need not be disclosed. Include a caption describing the maximum account fee (e.g., \"Maximum Account Maintenance Fee\" or \"Maximum Cash Management Fee\"). State the maximum annual account fee as either a fixed dollar amount or a percentage of assets. Include in a parenthetical to the caption the basis on which any percentage is calculated. If an account fee is charged only to accounts that do not meet a certain threshold (e.g., accounts under $5)", "label": "Maximum Account Fee (as a percentage of Assets)" } } }, "localname": "MaximumAccountFeeOverAssets", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_MaximumCumulativeSalesChargeOverOfferingPrice": { "auth_ref": [ "r36" ], "lang": { "en-us": { "role": { "documentation": "Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price). If a sales charge (load) is imposed on shares purchased with reinvested capital gains distributions or returns of capital, include the bracketed words in the third caption.", "label": "Maximum Cumulative Sales Charge (as a percentage of Offering Price)" } } }, "localname": "MaximumCumulativeSalesChargeOverOfferingPrice", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_MaximumCumulativeSalesChargeOverOther": { "auth_ref": [ "r36" ], "lang": { "en-us": { "role": { "documentation": "Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price). If a sales charge (load) is imposed on shares purchased with reinvested capital gains distributions or returns of capital, include the bracketed words in the third caption.", "label": "Maximum Cumulative Sales Charge (as a percentage)" } } }, "localname": "MaximumCumulativeSalesChargeOverOther", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_MaximumDeferredSalesChargeOverOfferingPrice": { "auth_ref": [ "r17" ], "lang": { "en-us": { "role": { "documentation": "Maximum Deferred Sales Charge (Load) (as a percentage of ____) A.3.instructions.2.a.i \"Maximum Deferred Sales Charge (Load)\" includes the maximum total deferred sales charge (load) payable upon redemption, in installments, or both, expressed as a percentage of the amount or amounts stated in response to Item 7(a), except that, for a sales charge (load) based on net asset value at the time of purchase, show the sales charge (load) as a percentage of the offering price at the time of purchase. A Fund may include in a footnote to the table, if applicable, a tabular presentation showing the amount of deferred sales charges (loads) over time or a narrative explanation of the sales charges (loads) (e.g., __% in the first year after purchase, declining to __% in the __ year and eliminated thereafter). A.3.instructions.2.a.ii If more than one type of sales charge (load) is imposed (e.g., a deferred sales charge (load) and a front-end sales charge (load)), the first caption in the table should read \"Maximum Sales Charge (Load)\" and show the maximum cumulative percentage. Show the percentage amounts and the terms of each sales charge (load) comprising that figure on separate lines below.", "label": "Maximum Deferred Sales Charge (as a percentage of Offering Price)" } } }, "localname": "MaximumDeferredSalesChargeOverOfferingPrice", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_MaximumDeferredSalesChargeOverOther": { "auth_ref": [ "r17" ], "lang": { "en-us": { "role": { "documentation": "Maximum Deferred Sales Charge (Load) (as a percentage of ____) \"Maximum Deferred Sales Charge (Load)\" includes the maximum total deferred sales charge (load) payable upon redemption, in installments, or both, expressed as a percentage of the amount or amounts stated in response to Item 7(a), except that, for a sales charge (load) based on net asset value at the time of purchase, show the sales charge (load) as a percentage of the offering price at the time of purchase. A Fund may include in a footnote to the table, if applicable, a tabular presentation showing the amount of deferred sales charges (loads) over time or a narrative explanation of the sales charges (loads) (e.g., __% in the first year after purchase, declining to __% in the __ year and eliminated thereafter). If more than one type of sales charge (load) is imposed (e.g., a deferred sales charge (load) and a front-end sales charge (load)), the first caption in the table should read \"Maximum Sales Charge (Load)\" and show the maximum cumulative percentage. Show the percentage amounts and the terms of each sales charge (load) comprising that figure on separate lines below.", "label": "Maximum Deferred Sales Charge (as a percentage)", "verboseLabel": "Maximum Deferred Sales Charge (load) (as a percentage of the lower of original purchase price or redemption proceeds)" } } }, "localname": "MaximumDeferredSalesChargeOverOther", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice": { "auth_ref": [ "r36" ], "lang": { "en-us": { "role": { "documentation": "Maximum Deferred Sales Charge (Load) (as a percentage of ____) A.3.instructions.2.a.i \"Maximum Deferred Sales Charge (Load)\" includes the maximum total deferred sales charge (load) payable upon redemption, in installments, or both, expressed as a percentage of the amount or amounts stated in response to Item 7(a), except that, for a sales charge (load) based on net asset value at the time of purchase, show the sales charge (load) as a percentage of the offering price at the time of purchase. A Fund may include in a footnote to the table, if applicable, a tabular presentation showing the amount of deferred sales charges (loads) over time or a narrative explanation of the sales charges (loads) (e.g., __% in the first year after purchase, declining to __% in the __ year and eliminated thereafter). A.3.instructions.2.a.ii If more than one type of sales charge (load) is imposed (e.g., a deferred sales charge (load) and a front-end sales charge (load)), the first caption in the table should read \"Maximum Sales Charge (Load)\" and show the maximum cumulative percentage. Show the percentage amounts and the terms of each sales charge (load) comprising that figure on separate lines below.", "label": "Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)", "verboseLabel": "Maximum Sales Charge (load) Imposed on Purchases (as a percentage of offering price)" } } }, "localname": "MaximumSalesChargeImposedOnPurchasesOverOfferingPrice", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther": { "auth_ref": [ "r39" ], "lang": { "en-us": { "role": { "documentation": "Maximum Sales Charge (Load) Imposed on Reinvested Dividends[and other Distributions] (as a percentage of ____)", "label": "Maximum Sales Charge on Reinvested Dividends and Distributions (as a percentage)" } } }, "localname": "MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_MoneyMarketSevenDayTaxEquivalentYield": { "auth_ref": [ "r64" ], "lang": { "en-us": { "role": { "documentation": "Calculate a Money Market Fund's 7-day yield under Item 21(a); the Fund's average annual total return under Item 21(b)(1); and the Fund's average annual total return (after taxes on distributions) and average annual total return (after taxes on distributions and redemption) under Items 21(b)(2) and (3), respectively.", "label": "Money Market Seven Day Tax Equivalent Yield" } } }, "localname": "MoneyMarketSevenDayTaxEquivalentYield", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_MoneyMarketSevenDayYield": { "auth_ref": [ "r64" ], "lang": { "en-us": { "role": { "documentation": "Calculate a Money Market Fund's 7-day yield under Item 21(a); the Fund's average annual total return under Item 21(b)(1); and the Fund's average annual total return (after taxes on distributions) and average annual total return (after taxes on distributions and redemption) under Items 21(b)(2) and (3), respectively.", "label": "Money Market Seven Day Yield" } } }, "localname": "MoneyMarketSevenDayYield", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_MoneyMarketSevenDayYieldCaption": { "auth_ref": [ "r64" ], "lang": { "en-us": { "role": { "documentation": "Calculate a Money Market Fund's 7-day yield under Item 21(a); the Fund's average annual total return under Item 21(b)(1); and the Fund's average annual total return (after taxes on distributions) and average annual total return (after taxes on distributions and redemption) under Items 21(b)(2) and (3), respectively.", "label": "Money Market Seven Day Yield, Caption [Text]" } } }, "localname": "MoneyMarketSevenDayYieldCaption", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_MoneyMarketSevenDayYieldColumnName": { "auth_ref": [ "r64" ], "lang": { "en-us": { "role": { "documentation": "Calculate a Money Market Fund's 7-day yield under Item 21(a); the Fund's average annual total return under Item 21(b)(1); and the Fund's average annual total return (after taxes on distributions) and average annual total return (after taxes on distributions and redemption) under Items 21(b)(2) and (3), respectively.", "label": "Money Market Seven Day Yield Column [Text]" } } }, "localname": "MoneyMarketSevenDayYieldColumnName", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_MoneyMarketSevenDayYieldPhone": { "auth_ref": [ "r66" ], "lang": { "en-us": { "role": { "documentation": "A Fund (other than a Money Market Fund) may include the Fund's yield calculated under Item 21(b)(2). Any Fund may include its tax-equivalent yield calculated under Item 21. If a Fund's yield is included, provide a toll-free (or collect) telephone number that investors can use to obtain current yield information.", "label": "Money Market Seven Day Yield Phone" } } }, "localname": "MoneyMarketSevenDayYieldPhone", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_NetExpensesOverAssets": { "auth_ref": [ "r38" ], "calculation": { "http://www.janushenderson.com/role/ScheduleAnnualFundOperatingExpenses000013": { "order": null, "parentTag": null, "root": true, "weight": null } }, "lang": { "en-us": { "role": { "documentation": "Total Annual Fund Operating Expenses.", "label": "Net Expenses (as a percentage of Assets)", "totalLabel": "Total Annual Fund Operating Expenses After Fee Waiver", "verboseLabel": "Total Annual Fund Operating Expenses After Fee Waiver" } } }, "localname": "NetExpensesOverAssets", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_ObjectiveHeading": { "auth_ref": [ "r6" ], "lang": { "en-us": { "role": { "documentation": "Investment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).", "label": "Objective [Heading]" } } }, "localname": "ObjectiveHeading", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ObjectivePrimaryTextBlock": { "auth_ref": [ "r6" ], "lang": { "en-us": { "role": { "documentation": "Investment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).", "label": "Objective, Primary [Text Block]" } } }, "localname": "ObjectivePrimaryTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_ObjectiveSecondaryTextBlock": { "auth_ref": [ "r6" ], "lang": { "en-us": { "role": { "documentation": "Investment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).", "label": "Objective, Secondary [Text Block]" } } }, "localname": "ObjectiveSecondaryTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_OperatingExpensesCaption": { "auth_ref": [ "r43" ], "lang": { "en-us": { "role": { "documentation": "Annual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investment)", "label": "Operating Expenses Caption [Text]" } } }, "localname": "OperatingExpensesCaption", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_OperatingExpensesColumnName": { "auth_ref": [ "r43" ], "lang": { "en-us": { "role": { "documentation": "Annual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investment)", "label": "Operating Expenses Column [Text]" } } }, "localname": "OperatingExpensesColumnName", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_OtherExpensesNewFundBasedOnEstimates": { "auth_ref": [ "r34" ], "lang": { "en-us": { "role": { "documentation": "This element represents the disclosure for new funds that \"Other Expenses\" are based on estimated amounts for the current fiscal year.", "label": "Other Expenses, New Fund, Based on Estimates [Text]" } } }, "localname": "OtherExpensesNewFundBasedOnEstimates", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_OtherExpensesOverAssets": { "auth_ref": [ "r23" ], "calculation": { "http://www.janushenderson.com/role/ScheduleAnnualFundOperatingExpenses000013": { "order": 40.0, "parentTag": "rr_ExpensesOverAssets", "weight": 1.0 } }, "lang": { "en-us": { "role": { "documentation": "\"Other Expenses\" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]). \"Other Expenses\" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's \"Other Expenses,\" disclose in a footnote to the table what \"Other Expenses\" would have been had the extraordinary expenses been included.", "label": "Other Expenses (as a percentage of Assets):", "totalLabel": "Other Expenses", "verboseLabel": "Other Expenses" } } }, "localname": "OtherExpensesOverAssets", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativePure4Type" }, "rr_PerformanceAdditionalMarketIndex": { "auth_ref": [ "r56" ], "lang": { "en-us": { "role": { "documentation": "Include the bar chart and table required by paragraphs (b)(2)(ii) and (iii) of this section. Provide a brief explanation of how the information illustrates the variability of the Fund's returns (e.g., by stating that the information provides some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance). Provide a statement to the effect that the Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.", "label": "Performance Additional Market Index [Text]" } } }, "localname": "PerformanceAdditionalMarketIndex", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PerformanceAvailabilityPhone": { "auth_ref": [ "r56" ], "lang": { "en-us": { "role": { "documentation": "If applicable, include a statement explaining that updated performance information is available and providing a Web site address and/or toll-free (or collect) telephone number where the updated information may be obtained.", "label": "Performance Availability Phone [Text]" } } }, "localname": "PerformanceAvailabilityPhone", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PerformanceAvailabilityWebSiteAddress": { "auth_ref": [ "r56" ], "lang": { "en-us": { "role": { "documentation": "If applicable, include a statement explaining that updated performance information is available and providing a Website address and/or toll-free (or collect) telephone number where the updated information may be obtained.", "label": "Performance Availability Website Address [Text]" } } }, "localname": "PerformanceAvailabilityWebSiteAddress", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PerformanceInformationIllustratesVariabilityOfReturns": { "auth_ref": [ "r56" ], "lang": { "en-us": { "role": { "documentation": "Include the bar chart and table required by paragraphs (b)(2)(ii) and (iii) of this section. Provide a brief explanation of how the information illustrates the variability of the Fund's returns (e.g., by stating that the information provides some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance). Provide a statement to the effect that the Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.", "label": "Performance Information Illustrates Variability of Returns [Text]" } } }, "localname": "PerformanceInformationIllustratesVariabilityOfReturns", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PerformanceMeasureAxis": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "The Performance Measure Axis has members that distinguish different returns according to whether they are Before Taxes (the default), After Taxes on Distributions, After Taxes on Distributions and Sales, or are a pre-tax measure of returns based on a broadly available market index.", "label": "Performance Measure [Axis]" } } }, "localname": "PerformanceMeasureAxis", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PerformanceMeasureDomain": { "auth_ref": [], "lang": { "en-us": { "role": { "documentation": "The default member of the Performance Measure axis. It represents any return that is measured before taxes.", "label": "Before Taxes" } } }, "localname": "PerformanceMeasureDomain", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "domainItemType" }, "rr_PerformanceNarrativeTextBlock": { "auth_ref": [ "r55" ], "lang": { "en-us": { "role": { "documentation": "Risk/Return Bar Chart and Table.", "label": "Performance Narrative [Text Block]" } } }, "localname": "PerformanceNarrativeTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_PerformanceOneYearOrLess": { "auth_ref": [ "r56", "r63" ], "lang": { "en-us": { "role": { "documentation": "For a Fund that provides annual total returns for only one calendar year or for a Fund that does not include the bar chart because it does not have annual returns for a full calendar year, modify, as appropriate, the narrative explanation required by stating that the information gives some indication of the risks of an investment in the Fund by comparing the Fund's performance with a broad measure of market performance). Provide a brief explanation of how the information illustrates the variability of the Fund's returns (e.g., by stating that the information provides some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance). Provide a statement to the effect that the Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.", "label": "Performance One Year or Less [Text]" } } }, "localname": "PerformanceOneYearOrLess", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PerformancePastDoesNotIndicateFuture": { "auth_ref": [ "r56" ], "lang": { "en-us": { "role": { "documentation": "Include the bar chart and table required by paragraphs (b)(2)(ii) and (iii) of this section. Provide a brief explanation of how the information illustrates the variability of the Fund's returns (e.g., by stating that the information provides some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance). Provide a statement to the effect that the Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.", "label": "Performance Past Does Not Indicate Future [Text]" } } }, "localname": "PerformancePastDoesNotIndicateFuture", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PerformanceTableClosingTextBlock": { "auth_ref": [ "r58" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a table showing the Fund's (A) average annual total return; (B) average annual total return (after taxes on distributions); and (C) average annual total return (after taxes on distributions and redemption). A Money Market Fund should show only the returns described in clause (A) of the preceding sentence. All returns should be shown for 1-, 5-, and 10- calendar year periods ending on the date of the most recently completed calendar year (or for the life of the Fund, if shorter), but only for periods subsequent to the effective date of the Fund's registration statement. The table also should show the returns of an appropriate broad-based securities market index as defined in Instruction 5 to Item 22(b)(7) for the same periods. A Fund that has been in existence for more than 10 years also may include returns for the life of the Fund. A Money Market Fund may provide the Fund's 7-day yield ending on the date of the most recent calendar year or disclose a toll-free (or collect) telephone number that investors can use to obtain the Fund's current 7-day yield. For a Fund (other than a Money Market Fund or a Fund described in General Instruction C.3.(d)(iii)), provide the information in the following table with the specified captions AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, _____)", "label": "Performance Table Closing [Text Block]" } } }, "localname": "PerformanceTableClosingTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_PerformanceTableDoesReflectSalesLoads": { "auth_ref": [ "r58" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a table showing the Fund's (A) average annual total return; (B) average annual total return (after taxes on distributions); and (C) average annual total return (after taxes on distributions and redemption). A Money Market Fund should show only the returns described in clause (A) of the preceding sentence. All returns should be shown for 1-, 5-, and 10- calendar year periods ending on the date of the most recently completed calendar year (or for the life of the Fund, if shorter), but only for periods subsequent to the effective date of the Fund's registration statement. The table also should show the returns of an appropriate broad-based securities market index as defined in Instruction 5 to Item 22(b)(7) for the same periods. A Fund that has been in existence for more than 10 years also may include returns for the life of the Fund. A Money Market Fund may provide the Fund's 7-day yield ending on the date of the most recent calendar year or disclose a toll-free (or collect) telephone number that investors can use to obtain the Fund's current 7-day yield. For a Fund (other than a Money Market Fund or a Fund described in General Instruction C.3.(d)(iii)), provide the information in the following table with the specified captions AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, _____)", "label": "Performance Table Does Reflect Sales Loads" } } }, "localname": "PerformanceTableDoesReflectSalesLoads", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PerformanceTableExplanationAfterTaxHigher": { "auth_ref": [ "r77" ], "lang": { "en-us": { "role": { "documentation": "If average annual total return (after taxes on distributions and redemption) is higher than average annual total return, the reason for this result may be explained.", "label": "Performance Table Explanation after Tax Higher" } } }, "localname": "PerformanceTableExplanationAfterTaxHigher", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PerformanceTableFootnotesReasonPerformanceInformationForClassDifferentFromImmediatelyPrecedingPeriod": { "auth_ref": [ "r70" ], "lang": { "en-us": { "role": { "documentation": "This element represents disclosure when presented performance information for a class is different from the class selected for the most immediately preceding period (Form N-1A, Item 2., Instr. 3.(c).(ii).(D)).", "label": "Performance Table Footnotes, Reason Performance Information for Class Different from Immediately Preceding Period [Text]" } } }, "localname": "PerformanceTableFootnotesReasonPerformanceInformationForClassDifferentFromImmediatelyPrecedingPeriod", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PerformanceTableFootnotesTextBlock": { "auth_ref": [ "r58" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a table showing the Fund's (A) average annual total return; (B) average annual total return (after taxes on distributions); and (C) average annual total return (after taxes on distributions and redemption). A Money Market Fund should show only the returns described in clause (A) of the preceding sentence. All returns should be shown for 1-, 5-, and 10- calendar year periods ending on the date of the most recently completed calendar year (or for the life of the Fund, if shorter), but only for periods subsequent to the effective date of the Fund's registration statement. The table also should show the returns of an appropriate broad-based securities market index as defined in Instruction 5 to Item 22(b)(7) for the same periods. A Fund that has been in existence for more than 10 years also may include returns for the life of the Fund. A Money Market Fund may provide the Fund's 7-day yield ending on the date of the most recent calendar year or disclose a toll-free (or collect) telephone number that investors can use to obtain the Fund's current 7-day yield. For a Fund (other than a Money Market Fund or a Fund described in General Instruction C.3.(d)(iii)), provide the information in the following table with the specified captions AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, _____)", "label": "Performance Table Footnotes" } } }, "localname": "PerformanceTableFootnotesTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_PerformanceTableHeading": { "auth_ref": [ "r70" ], "lang": { "en-us": { "role": { "documentation": "This item represents Average Annual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.", "label": "Performance Table Heading" } } }, "localname": "PerformanceTableHeading", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PerformanceTableMarketIndexChanged": { "auth_ref": [ "r65" ], "lang": { "en-us": { "role": { "documentation": "If the Fund selects an index that is different from the index used in a table for the immediately preceding period, explain the reason(s) for the selection of a different index and provide information for both the newly selected and the former index.", "label": "Performance Table Market Index Changed" } } }, "localname": "PerformanceTableMarketIndexChanged", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PerformanceTableNarrativeTextBlock": { "auth_ref": [ "r74" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a table showing the Fund's (A) average annual total return; (B) average annual total return (after taxes on distributions); and (C) average annual total return (after taxes on distributions and redemption). A Money Market Fund should show only the returns described in clause (A) of the preceding sentence. All returns should be shown for 1-, 5-, and 10- calendar year periods ending on the date of the most recently completed calendar year (or for the life of the Fund, if shorter), but only for periods subsequent to the effective date of the Fund's registration statement. The table also should show the returns of an appropriate broad-based securities market index as defined in Instruction 5 to Item 22(b)(7) for the same periods. A Fund that has been in existence for more than 10 years also may include returns for the life of the Fund. A Money Market Fund may provide the Fund's 7-day yield ending on the date of the most recent calendar year or disclose a toll-free (or collect) telephone number that investors can use to obtain the Fund's current 7-day yield. For a Fund (other than a Money Market Fund or a Fund described in General Instruction C.3.(d)(iii)), provide the information in the following table with the specified captions AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, _____). For a Fund that provides annual total returns for only one calendar year or for a Fund that does not include the bar chart because it does not have annual returns for a full calendar year, modify, as appropriate, the narrative explanation required by paragraph (c)(2)(i) (e.g., by stating that the information gives some indication of the risks of an investment in the Fund by comparing the Fund's performance with a broad measure of market performance).", "label": "Performance Table Narrative" } } }, "localname": "PerformanceTableNarrativeTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_PerformanceTableNotRelevantToTaxDeferred": { "auth_ref": [ "r75" ], "lang": { "en-us": { "role": { "documentation": "Provide a brief explanation that the actual after-tax returns depend on an investor's tax situation and may differ from those shown, and after-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.", "label": "Performance Table Not Relevant to Tax Deferred" } } }, "localname": "PerformanceTableNotRelevantToTaxDeferred", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PerformanceTableOneClassOfAfterTaxShown": { "auth_ref": [ "r58", "r76" ], "lang": { "en-us": { "role": { "documentation": "Provide a brief explanation that if the Fund is a Multiple Class Fund that offers more than one Class in the prospectus, after-tax returns are shown for only one Class and after-tax returns for other Classes will vary.", "label": "Performance Table One Class of after Tax Shown [Text]" } } }, "localname": "PerformanceTableOneClassOfAfterTaxShown", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PerformanceTableUsesHighestFederalRate": { "auth_ref": [ "r58" ], "lang": { "en-us": { "role": { "documentation": "Provide a brief explanation that after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.", "label": "Performance Table Uses Highest Federal Rate" } } }, "localname": "PerformanceTableUsesHighestFederalRate", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PortfolioTurnoverHeading": { "auth_ref": [ "r33" ], "lang": { "en-us": { "role": { "documentation": "Disclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.", "label": "Portfolio Turnover [Heading]" } } }, "localname": "PortfolioTurnoverHeading", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_PortfolioTurnoverRate": { "auth_ref": [ "r11" ], "lang": { "en-us": { "role": { "documentation": "This element represents the rate of portfolio turnover presented as a percentage (SEC Form N-1A 2006-09-14 A.3.example.3 Portfolio Turnover A.3.instructions.5 Portfolio Turnover).", "label": "Portfolio Turnover, Rate" } } }, "localname": "PortfolioTurnoverRate", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_PortfolioTurnoverTextBlock": { "auth_ref": [ "r11" ], "lang": { "en-us": { "role": { "documentation": "Disclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.", "label": "Portfolio Turnover [Text Block]" } } }, "localname": "PortfolioTurnoverTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_ProspectusDate": { "auth_ref": [ "r4" ], "lang": { "en-us": { "role": { "documentation": "The date of the prospectus.", "label": "Prospectus Date" } } }, "localname": "ProspectusDate", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements", "http://xbrl.sec.gov/rr/role/RiskReturnDetailData" ], "xbrltype": "dateItemType" }, "rr_ProspectusShareClassAxis": { "auth_ref": [ "r2" ], "lang": { "en-us": { "role": { "documentation": "Prospectus Share Class Axis.", "label": "Share Class [Axis]" } } }, "localname": "ProspectusShareClassAxis", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "stringItemType" }, "rr_ProspectusTable": { "auth_ref": [ "r2" ], "lang": { "en-us": { "role": { "documentation": "Prospectus Table.", "label": "Prospectus:" } } }, "localname": "ProspectusTable", "nsuri": "http://xbrl.sec.gov/rr/2021", "xbrltype": "stringItemType" }, "rr_RedemptionFee": { "auth_ref": [ "r40" ], "lang": { "en-us": { "role": { "documentation": "\"Redemption Fee\" (as a percentage of amount redeemed, if applicable) If the Fund is an Exchange-Traded Fund and issues or redeems shares in creation units of not less than 25,000 shares each, exclude any fees charged for the purchase and redemption of the Fund's creation units. \"Redemption Fee\" includes a fee charged for any redemption of the Fund's shares, but does not include a deferred sales charge (load) imposed upon redemption.", "label": "Redemption Fee", "negatedLabel": "Redemption Fee" } } }, "localname": "RedemptionFee", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonPositiveMonetaryType" }, "rr_RedemptionFeeOverRedemption": { "auth_ref": [ "r18" ], "lang": { "en-us": { "role": { "documentation": "\"Redemption Fee\" (as a percentage of amount redeemed, if applicable) If the Fund is an Exchange-Traded Fund and issues or redeems shares in creation units of not less than 25,000 shares each, exclude any fees charged for the purchase and redemption of the Fund's creation units. \"Redemption Fee\" includes a fee charged for any redemption of the Fund's shares, but does not include a deferred sales charge (load) imposed upon redemption.", "label": "Redemption Fee (as a percentage of Amount Redeemed)", "negatedLabel": "Redemption Fee (as a percentage of Amount Redeemed)" } } }, "localname": "RedemptionFeeOverRedemption", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonPositivePure4Type" }, "rr_Risk": { "auth_ref": [ "r46" ], "lang": { "en-us": { "role": { "documentation": "Narrative Risk Disclosure.", "label": "Risk [Text]" } } }, "localname": "Risk", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_RiskCaption": { "auth_ref": [ "r46" ], "lang": { "en-us": { "role": { "documentation": "Narrative Risk Disclosure.", "label": "Risk Caption" } } }, "localname": "RiskCaption", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_RiskClosingTextBlock": { "auth_ref": [ "r49" ], "lang": { "en-us": { "role": { "documentation": "(ii) (A) If the Fund is a Money Market Fund that is not a government Money Market Fund, as defined in \u00a7270.2a\u2013 7(a)(16) or a retail Money Market Fund, as defined in \u00a7 270.2a\u20137(a)(25), include the following statement: You could lose money by investing in the Fund. Because the share price of the Fund will fluctuate, when you sell your shares they may be worth more or less than what you originally paid for them. The Fund may impose a fee upon sale of your shares or may temporarily suspend your ability to sell shares if the Fund's liquidity falls below required minimums because of market conditions or other factors. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Fund's sponsor has no legal obligation to provide financial support to the Fund, and you should not expect that the sponsor will provide financial support to the Fund at any time. (B) If the Fund is a Money Market Fund that is a government Money Market Fund, as defined in \u00a7 270.2a\u20137(a)(16), or a retail Money Market Fund, as defined in \u00a7 270.2a\u20137(a)(25), and that is subject to the requirements of \u00a7\u00a7 270.2a\u20137(c)(2)(i) and/or (ii) of this chapter (or is not subject to the requirements of \u00a7\u00a7 270.2a\u20137(c)(2)(i) and/or (ii) of this chapter pursuant to \u00a7 270.2a\u20137(c)(2)(iii) of this chapter, but has chosen to rely on the ability to impose liquidity fees and suspend redemptions consistent with the requirements of \u00a7\u00a7 270.2a\u20137(c)(2)(i) and/or (ii)), include the following statement: You could lose money by investing in the Fund. Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. The Fund may impose a fee upon sale of your shares or may temporarily suspend your ability to sell shares if the Fund's liquidity falls below required minimums because of market conditions or other factors. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Fund's sponsor has no legal obligation to provide financial support to the Fund, and you should not expect that the sponsor will provide financial support to the Fund at any time. (C) If the Fund is a Money Market Fund that is a government Money Market Fund, as defined in \u00a7 270.2a\u20137(a)(16), that is not subject to the requirements of \u00a7\u00a7 270.2a\u20137(c)(2)(i) and/or (ii) of this chapter pursuant to \u00a7 270.2a\u20137(c)(2)(iii) of this chapter, and that has not chosen to rely on the ability to impose liquidity fees and suspend redemptions consistent with the requirements of \u00a7\u00a7 270.2a\u20137(c)(2)(i) and/or (ii), include the following statement: You could lose money by investing in the Fund. Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Fund's sponsor has no legal obligation to provide financial support to the Fund, and you should not expect that the sponsor will provide financial support to the Fund at any time. Instruction. If an affiliated person, promoter, or principal underwriter of the Fund, or an affiliated person of such a person, has contractually committed to provide financial support to the Fund, and the term of the agreement will extend for at least one year following the effective date of the Fund's registration statement, the statement specified in Item 4(b)(1)(ii)(A), Item 4(b)(1)(ii)(B), or Item 4(b)(1)(ii)(C) may omit the last sentence (\"The Fund's sponsor has no legal obligation to provide financial support to the Fund, and you should not expect that the sponsor will provide financial support to the Fund at any time.\"). For purposes of this Instruction, the term \"financial support\" includes any capital contribution, purchase of a security from the Fund in reliance on \u00a7 270.17a\u20139, purchase of any defaulted or devalued security at par, execution of letter of credit or letter of indemnity, capital support agreement (whether or not the Fund ultimately received support), performance guarantee, or any other similar action reasonably intended to increase or stabilize the value or liquidity of the fund's portfolio; however, the term \"financial support\" excludes any routine waiver of fees or reimbursement of fund expenses, routine inter-fund lending, routine inter-fund purchases of fund shares, or any action that would qualify as financial support as defined above, that the board of directors has otherwise determined not to be reasonably intended to increase or stabilize the value or liquidity of the fund's portfolio. (iii) If the Fund is advised by or sold through an insured depository institution, state that: An investment in the Fund is not a deposit of the bank and is not insured or guaranteed by the Federal Deposit Insurance corporation or any other government agency. Instruction. A Money Market Fund that is advised by or sold through an insured depository institution should combine the disclosure required by Items 4(b)(1)(ii) and (iii) in a single statement.", "label": "Risk Closing [Text Block]" } } }, "localname": "RiskClosingTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_RiskColumnName": { "auth_ref": [ "r46" ], "lang": { "en-us": { "role": { "documentation": "Narrative Risk Disclosure.", "label": "Risk Column [Text]" } } }, "localname": "RiskColumnName", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_RiskFootnotesTextBlock": { "auth_ref": [ "r46" ], "lang": { "en-us": { "role": { "documentation": "Narrative Risk Disclosure.", "label": "Risk Footnotes [Text Block]" } } }, "localname": "RiskFootnotesTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_RiskHeading": { "auth_ref": [ "r46" ], "lang": { "en-us": { "role": { "documentation": "Narrative Risk Disclosure.", "label": "Risk [Heading]" } } }, "localname": "RiskHeading", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_RiskLoseMoney": { "auth_ref": [ "r47", "r50", "r51", "r52" ], "lang": { "en-us": { "role": { "documentation": "Summarize the principal risks of investing in the Fund, including the risks to which the Fund's portfolio as a whole is subject and the circumstances reasonably likely to affect adversely the Fund's net asset value, yield, and total return. Unless the Fund is a Money Market Fund, disclose that loss of money is a risk of investing in the Fund. If the Fund is a Money Market Fund, include the following statement: \"You could lose money by investing in the Fund.\"", "label": "Risk Lose Money [Text]" } } }, "localname": "RiskLoseMoney", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_RiskMoneyMarketFundMayImposeFeesOrSuspendSales": { "auth_ref": [ "r50", "r51" ], "lang": { "en-us": { "role": { "documentation": "Include the statement \"The Fund may impose a fee upon sale of your shares or may temporarily suspend your ability to sell shares if the Fund's liquidity falls below required minimums because of market conditions or other factors.\"", "label": "Risk Money Market Fund May Impose Fees or Suspend Sales [Text]" } } }, "localname": "RiskMoneyMarketFundMayImposeFeesOrSuspendSales", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_RiskMoneyMarketFundMayNotPreserveDollar": { "auth_ref": [ "r51", "r52" ], "lang": { "en-us": { "role": { "documentation": "Include the statement \"Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so.\"", "label": "Risk Money Market Fund May Not Preserve Dollar [Text]" } } }, "localname": "RiskMoneyMarketFundMayNotPreserveDollar", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_RiskMoneyMarketFundPriceFluctuates": { "auth_ref": [ "r50" ], "lang": { "en-us": { "role": { "documentation": "Include the statement \"Because the share price of the Fund will fluctuate, when you sell your shares they may be worth more or less than what you originally paid for them.\"", "label": "Risk Money Market Fund Price Fluctuates [Text]" } } }, "localname": "RiskMoneyMarketFundPriceFluctuates", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_RiskMoneyMarketFundSponsorMayNotProvideSupport": { "auth_ref": [ "r50", "r51", "r52" ], "lang": { "en-us": { "role": { "documentation": "Include the statement \"The Fund's sponsor has no legal obligation to provide financial support to the Fund, and you should not expect that the sponsor will provide financial support to the Fund at any time.\"", "label": "Risk Money Market Fund Sponsor May Not Provide Support [Text]" } } }, "localname": "RiskMoneyMarketFundSponsorMayNotProvideSupport", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_RiskNarrativeTextBlock": { "auth_ref": [ "r48" ], "lang": { "en-us": { "role": { "documentation": "Narrative Risk Disclosure. A Fund may, in responding to this Item, describe the types of investors for whom the Fund is intended or the types of investment goals that may be consistent with an investment in the Fund.", "label": "Risk Narrative [Text Block]" } } }, "localname": "RiskNarrativeTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_RiskNondiversifiedStatus": { "auth_ref": [ "r54" ], "lang": { "en-us": { "role": { "documentation": "If applicable, state that the Fund is non-diversified, describe the effect of non-diversification (e.g., disclose that, compared with other funds, the Fund may invest a greater percentage of its assets in a particular issuer), and summarize the risks of investing in a non-diversified fund.", "label": "Risk Nondiversified Status [Text]" } } }, "localname": "RiskNondiversifiedStatus", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_RiskNotInsured": { "auth_ref": [ "r50", "r51", "r52" ], "lang": { "en-us": { "role": { "documentation": "Include the statement \"An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.\"", "label": "RIsk Not Insured [Text]" } } }, "localname": "RiskNotInsured", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_RiskNotInsuredDepositoryInstitution": { "auth_ref": [ "r53" ], "lang": { "en-us": { "role": { "documentation": "If the Fund is advised by or sold through an insured depository institution, state that \"An investment in the Fund is not a deposit of the bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.\"", "label": "Risk Not Insured Depository Institution [Text]" } } }, "localname": "RiskNotInsuredDepositoryInstitution", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_RiskReturnAbstract": { "auth_ref": [], "localname": "RiskReturnAbstract", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "stringItemType" }, "rr_RiskReturnHeading": { "auth_ref": [ "r5" ], "lang": { "en-us": { "role": { "documentation": "Risk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicated", "label": "Risk/Return [Heading]" } } }, "localname": "RiskReturnHeading", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ShareClassDomain": { "auth_ref": [ "r3" ], "lang": { "en-us": { "role": { "documentation": "All members of this domain must be elements with name starting with \"C\" and consisting of a 9-digit Fund share class CIK.", "label": "Share Classes" } } }, "localname": "ShareClassDomain", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares", "http://www.janushenderson.com/role/DocumentDocumentandEntityInformationElements" ], "xbrltype": "domainItemType" }, "rr_ShareholderFeeOther": { "auth_ref": [ "r37" ], "lang": { "en-us": { "role": { "documentation": "Other Expenses", "label": "Shareholder Fee, Other" } } }, "localname": "ShareholderFeeOther", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "NonNegativeMonetaryType" }, "rr_ShareholderFeesCaption": { "auth_ref": [ "r35" ], "lang": { "en-us": { "role": { "documentation": "Shareholder Fees (fees paid directly from your investment).", "label": "Shareholder Fees Caption [Text]" } } }, "localname": "ShareholderFeesCaption", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ShareholderFeesColumnName": { "auth_ref": [ "r35" ], "lang": { "en-us": { "role": { "documentation": "Shareholder Fees (fees paid directly from your investment).", "label": "Shareholder Fees Column [Text]" } } }, "localname": "ShareholderFeesColumnName", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_StrategyHeading": { "auth_ref": [ "r45" ], "lang": { "en-us": { "role": { "documentation": "Principal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.", "label": "Strategy [Heading]" } } }, "localname": "StrategyHeading", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_StrategyNarrativeTextBlock": { "auth_ref": [ "r45" ], "lang": { "en-us": { "role": { "documentation": "Principal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.", "label": "Strategy Narrative [Text Block]" } } }, "localname": "StrategyNarrativeTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_StrategyPortfolioConcentration": { "auth_ref": [ "r45" ], "lang": { "en-us": { "role": { "documentation": "Principal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.", "label": "Strategy Portfolio Concentration [Text]" } } }, "localname": "StrategyPortfolioConcentration", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_SupplementToProspectusTextBlock": { "auth_ref": [ "r1" ], "lang": { "en-us": { "role": { "documentation": "This element contains the text of a prospectus supplement (submission type 497) not already contained in an element containing amended text or other data from a previous submission.", "label": "Supplement to Prospectus [Text Block]" } } }, "localname": "SupplementToProspectusTextBlock", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_ThirtyDayTaxEquivalentYield": { "auth_ref": [ "r66" ], "lang": { "en-us": { "role": { "documentation": "A Fund (other than a Money Market Fund) may include the Fund's yield calculated under Item 21(b)(2). Any Fund may include its tax-equivalent yield calculated under Item 21. If a Fund's yield is included, provide a toll-free (or collect) telephone number that investors can use to obtain current yield information.", "label": "Thirty Day Tax Equivalent Yield" } } }, "localname": "ThirtyDayTaxEquivalentYield", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_ThirtyDayYield": { "auth_ref": [ "r66" ], "lang": { "en-us": { "role": { "documentation": "A Fund (other than a Money Market Fund) may include the Fund's yield calculated under Item 21(b)(2). Any Fund may include its tax-equivalent yield calculated under Item 21. If a Fund's yield is included, provide a toll-free (or collect) telephone number that investors can use to obtain current yield information.", "label": "Thirty Day Yield" } } }, "localname": "ThirtyDayYield", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "pureItemType" }, "rr_ThirtyDayYieldCaption": { "auth_ref": [ "r66" ], "lang": { "en-us": { "role": { "documentation": "A Fund (other than a Money Market Fund) may include the Fund's yield calculated under Item 21(b)(2). Any Fund may include its tax-equivalent yield calculated under Item 21. If a Fund's yield is included, provide a toll-free (or collect) telephone number that investors can use to obtain current yield information.", "label": "Thirty Day Yield Caption" } } }, "localname": "ThirtyDayYieldCaption", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_ThirtyDayYieldColumnName": { "auth_ref": [ "r66" ], "lang": { "en-us": { "role": { "documentation": "A Fund (other than a Money Market Fund) may include the Fund's yield calculated under Item 21(b)(2). Any Fund may include its tax-equivalent yield calculated under Item 21. If a Fund's yield is included, provide a toll-free (or collect) telephone number that investors can use to obtain current yield information.", "label": "Thirty Day Yield Column [Text]" } } }, "localname": "ThirtyDayYieldColumnName", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "textBlockItemType" }, "rr_ThirtyDayYieldPhone": { "auth_ref": [ "r66" ], "lang": { "en-us": { "role": { "documentation": "A Fund (other than a Money Market Fund) may include the Fund's yield calculated under Item 21(b)(2). Any Fund may include its tax-equivalent yield calculated under Item 21. If a Fund's yield is included, provide a toll-free (or collect) telephone number that investors can use to obtain current yield information.", "label": "Thirty Day Yield Phone" } } }, "localname": "ThirtyDayYieldPhone", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" }, "rr_YearToDateReturnLabel": { "auth_ref": [ "r57" ], "lang": { "en-us": { "role": { "documentation": "If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.", "label": "Year to Date Return, Label" } } }, "localname": "YearToDateReturnLabel", "nsuri": "http://xbrl.sec.gov/rr/2021", "presentation": [ "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonAsiaEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonBalancedFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonContrarianFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEmergingMarketsFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEnterpriseFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonEuropeanFocusFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonFortyFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalEquityIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalLifeSciencesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalRealEstateFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSelectFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalSustainableEquityFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGlobalTechnologyandInnovationFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonGrowthandIncomeFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonInternationalOpportunitiesFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonOverseasFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonResearchFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassACSINRTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonTritonFundClassDShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassACSINTShares", "http://www.janushenderson.com/role/DisclosureRiskReturnDetailDataElementsJanusHendersonVentureFundClassDShares" ], "xbrltype": "stringItemType" } }, "unitCount": 2 } }, "std_ref": { "r0": { "Publisher": "Global LEI Foundation", "URI": "www.leiroc.org", "URIDate": "2013-08-21" }, "r1": { "Name": "Form", "Number": "N-1A", "Publisher": "SEC" }, "r10": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "3", "Subparagraph": "6", "Subsection": "example" }, "r11": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "3", "Publisher": "SEC", "Section": "3", "Subsection": "example" }, "r12": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "b", "Subsection": "instructions" }, "r13": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "c", "Subsection": "instructions" }, "r14": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "d", "Subsection": "instructions" }, "r15": { "Chapter": "A", "Clause": "i", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "d", "Subsection": "instructions" }, "r16": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "3", "Subsection": "instructions" }, "r17": { "Chapter": "A", "Clause": "i", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "3", "Subparagraph": "a", "Subsection": "instructions" }, "r18": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "3", "Subparagraph": "b", "Subsection": "instructions" }, "r19": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "3", "Subparagraph": "c", "Subsection": "instructions" }, "r2": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Publisher": "SEC" }, "r20": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "3", "Subparagraph": "d", "Subsection": "instructions" }, "r21": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "3", "Publisher": "SEC", "Section": "3", "Subparagraph": "a", "Subsection": "instructions" }, "r22": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "3", "Publisher": "SEC", "Section": "3", "Subparagraph": "b", "Subsection": "instructions" }, "r23": { "Chapter": "A", "Clause": "i", "Name": "Form", "Number": "N-1A", "Paragraph": "3", "Publisher": "SEC", "Section": "3", "Subparagraph": "c", "Subsection": "instructions" }, "r24": { "Chapter": "A", "Clause": "ii", "Name": "Form", "Number": "N-1A", "Paragraph": "3", "Publisher": "SEC", "Section": "3", "Subparagraph": "c", "Subsection": "instructions" }, "r25": { "Chapter": "A", "Clause": "iii", "Name": "Form", "Number": "N-1A", "Paragraph": "3", "Publisher": "SEC", "Section": "3", "Subparagraph": "c", "Subsection": "instructions" }, "r26": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "3", "Publisher": "SEC", "Section": "3", "Subparagraph": "d", "Subsection": "instructions" }, "r27": { "Chapter": "A", "Clause": "ii", "Exhibit": "B", "Name": "Form", "Number": "N-1A", "Paragraph": "3", "Publisher": "SEC", "Section": "3", "Subparagraph": "d", "Subsection": "instructions" }, "r28": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "3", "Publisher": "SEC", "Section": "3", "Subparagraph": "e", "Subsection": "instructions" }, "r29": { "Chapter": "A", "Clause": "vi", "Name": "Form", "Number": "N-1A", "Paragraph": "3", "Publisher": "SEC", "Section": "3", "Subparagraph": "f", "Subsection": "instructions" }, "r3": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "1", "Subsection": "a" }, "r30": { "Chapter": "A", "Clause": "vii", "Name": "Form", "Number": "N-1A", "Paragraph": "3", "Publisher": "SEC", "Section": "3", "Subparagraph": "f", "Subsection": "instructions" }, "r31": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "4", "Publisher": "SEC", "Section": "3", "Subsection": "instructions" }, "r32": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "4", "Publisher": "SEC", "Section": "3", "Subparagraph": "f", "Subsection": "instructions" }, "r33": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "5", "Publisher": "SEC", "Section": "3", "Subsection": "instructions" }, "r34": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "6", "Publisher": "SEC", "Section": "3", "Subparagraph": "a", "Subsection": "instructions" }, "r35": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subsection": "table" }, "r36": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "1", "Subsection": "table" }, "r37": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "10", "Subsection": "table" }, "r38": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "11", "Subsection": "table" }, "r39": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "3", "Subsection": "table" }, "r4": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "3", "Publisher": "SEC", "Section": "1", "Subsection": "a" }, "r40": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "4", "Subsection": "table" }, "r41": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "5", "Subsection": "table" }, "r42": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "6", "Subsection": "table" }, "r43": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "7", "Subsection": "table" }, "r44": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "9", "Subsection": "table" }, "r45": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Publisher": "SEC", "Section": "4", "Subsection": "a" }, "r46": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "4", "Subsection": "b" }, "r47": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "4", "Subparagraph": "i", "Subsection": "b" }, "r48": { "Chapter": "A", "Clause": "instruction", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "4", "Subparagraph": "i", "Subsection": "b" }, "r49": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "4", "Subparagraph": "ii", "Subsection": "b" }, "r5": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Publisher": "SEC", "Section": "2" }, "r50": { "Chapter": "A", "Clause": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "4", "Subparagraph": "ii", "Subsection": "b" }, "r51": { "Chapter": "A", "Clause": "B", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "4", "Subparagraph": "ii", "Subsection": "b" }, "r52": { "Chapter": "A", "Clause": "C", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "4", "Subparagraph": "ii", "Subsection": "b" }, "r53": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "4", "Subparagraph": "iii", "Subsection": "b" }, "r54": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "4", "Subparagraph": "iv", "Subsection": "b" }, "r55": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subsection": "b" }, "r56": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "i", "Subsection": "b" }, "r57": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "ii", "Subsection": "b" }, "r58": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "iii", "Subsection": "b" }, "r59": { "Chapter": "A", "Clause": "1", "Exhibit": "1", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "iii", "Subsection": "b" }, "r6": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Publisher": "SEC", "Section": "2", "Subsection": "a" }, "r60": { "Chapter": "A", "Clause": "1", "Exhibit": "2", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "iii", "Subsection": "b" }, "r61": { "Chapter": "A", "Clause": "1", "Exhibit": "5", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "iii", "Subsection": "b" }, "r62": { "Chapter": "A", "Clause": "1", "Exhibit": "a", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "instructions", "Subsection": "b" }, "r63": { "Chapter": "A", "Clause": "1", "Exhibit": "b", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "instructions", "Subsection": "b" }, "r64": { "Chapter": "A", "Clause": "2", "Exhibit": "a", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "instructions", "Subsection": "b" }, "r65": { "Chapter": "A", "Clause": "2", "Exhibit": "c", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "instructions", "Subsection": "b" }, "r66": { "Chapter": "A", "Clause": "2", "Exhibit": "d", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "instructions", "Subsection": "b" }, "r67": { "Chapter": "A", "Clause": "3", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "instructions", "Subsection": "b" }, "r68": { "Chapter": "A", "Clause": "3", "Exhibit": "a", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "instructions", "Subsection": "b" }, "r69": { "Chapter": "A", "Clause": "3", "Exhibit": "b", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "instructions", "Subsection": "b" }, "r7": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "1", "Subsection": "example" }, "r70": { "Chapter": "A", "Clause": "3", "Exhibit": "c", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "instructions", "Subsection": "b" }, "r71": { "Chapter": "A", "Clause": "3", "Example": "ii", "Exhibit": "c", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Sentence": "D", "Subparagraph": "instructions", "Subsection": "b" }, "r72": { "Chapter": "A", "Clause": "4", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "instructions", "Subsection": "b" }, "r73": { "Chapter": "A", "Clause": "5", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "instructions", "Subsection": "b" }, "r74": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "iv", "Subsection": "b" }, "r75": { "Chapter": "A", "Clause": "B", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "iv", "Subsection": "b" }, "r76": { "Chapter": "A", "Clause": "C", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "iv", "Subsection": "b" }, "r77": { "Chapter": "A", "Clause": "D", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "4", "Subparagraph": "iv", "Subsection": "b" }, "r78": { "Name": "Regulation 12B", "Number": "240", "Publisher": "SEC", "Section": "12", "Subsection": "b-2" }, "r79": { "Name": "Regulation S-T", "Number": "232", "Publisher": "SEC", "Section": "313" }, "r8": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "1", "Publisher": "SEC", "Section": "3", "Subparagraph": "2", "Subsection": "example" }, "r9": { "Chapter": "A", "Name": "Form", "Number": "N-1A", "Paragraph": "2", "Publisher": "SEC", "Section": "3", "Subparagraph": "1", "Subsection": "example" } }, "version": "2.1" }