XML 68 R56.htm IDEA: XBRL DOCUMENT
v3.25.1

Note 7 - Goodwill and Intangible Assets - Intangible Assets and Goodwill (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2025 | Mar. 31, 2024
Intangible assets, amortization | $ (2.8) | $ (0.1)
Accumulated amortization, balance | (62.8) | (62.1)
Foreign currency translation, accumulated amortization | (1.2) | (1.0)
Accumulated amortization, balance | (66.8) | (61.2)
Net intangible assets, balance | 2,473.3 | 2,431.3
Net intangible assets | 0.0 |
Foreign currency translation, Net intangible assets | 9.9 | (4.5)
Net intangible assets, balance | 2,480.4 | 2,426.7
Goodwill, balance | 1,550.4 | 1,290.3
Goodwill, addition | 16.0 |
Foreign currency translation, Goodwill | 20.8 | (8.1)
Goodwill, balance | 1,587.2 | 1,282.2
Balance | 54.1 |
Foreign currency translation, accumulated amortization | 1.2 | 1.0
Client Relationships [Member] |  |
Balance | 86.1 |
Intangible assets, amortization | 0.0 | 0.0
Additions | 0.0 |
Foreign currency translation, definite-lived intangible assets | 1.3 | (1.3)
Balance | 87.4 |
Balance |  | 68.6
Foreign currency translation, definite-lived intangible assets | 1.3 | (1.3)
Balance |  | 67.3
Investment Management Agreements [Member] |  |
Balance | 28.0 |
Additions | 0.0 |
Foreign currency translation, definite-lived intangible assets | 0.0 |
Balance | 28.0 |
Foreign currency translation, definite-lived intangible assets | 0.0 |
Definite Lived Trademarks [Member] |  |
Balance | 5.5 |
Additions | 0.0 |
Foreign currency translation, definite-lived intangible assets | 0.0 |
Balance | 5.5 |
Foreign currency translation, definite-lived intangible assets | 0.0 |
Investment Management Agreements [Member] |  |
Balance | 2,056.5 | 2,064.8
Foreign currency translation, indefinite-lived intangible assets | 9.8 | (4.2)
Balance | 2,066.3 | 2,060.6
Foreign currency translation | 9.8 | (4.2)
Trademarks [Member] |  |
Balance | 360.0 | 360.0
Foreign currency translation, indefinite-lived intangible assets | 0.0 | 0.0
Balance | 360.0 | 360.0
Foreign currency translation | $ 0.0 | $ 0.0

X
- Definition It represents the amount of accumulated amortization related to foreign currency translation gain loss. + References No definition available. + Details
Name: | jhg_AccumulatedAmortizationRelatedToForeignCurrencyTranslationGainLoss
Namespace Prefix: | jhg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of increase in assets, excluding financial assets. + References No definition available. + Details
Name: | jhg_IntangibleAssetsAcquired
Namespace Prefix: | jhg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase (decrease) to intangible assets, excluding financial assets and goodwill, lacking physical substance for foreign currency translation adjustments. + References No definition available. + Details
Name: | jhg_IntangibleAssetsTranslationAdjustments
Namespace Prefix: | jhg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 220 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 18 -Publisher FASB -URI https://asc.fasb.org/1943274/2147476153/220-40-55-18 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 220 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org/1943274/2147476153/220-40-55-11 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 220 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 24 -Publisher FASB -URI https://asc.fasb.org/1943274/2147476153/220-40-55-24 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 220 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 12 -Publisher FASB -URI https://asc.fasb.org/1943274/2147476148/220-40-50-12 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Name Accounting Standards Codification -Section 55 -Paragraph 40 -SubTopic 30 -Topic 350 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482640/350-30-55-40 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482686/350-30-45-2 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147476148/220-40-50-6 + Details
Name: | us-gaap_AmortizationOfIntangibleAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Name Accounting Standards Codification -Section 55 -Paragraph 40 -SubTopic 30 -Topic 350 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482640/350-30-55-40 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 10 -Name Accounting Standards Codification -Section S45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480265/350-10-S45-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(16)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of foreign currency translation gain (loss) which increases (decreases) assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References No definition available. + Details
Name: | us-gaap_FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Name Accounting Standards Codification -Section 55 -Paragraph 40 -SubTopic 30 -Topic 350 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482640/350-30-55-40 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 10 -Name Accounting Standards Codification -Section S45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480265/350-10-S45-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 928 -SubTopic 340 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478859/928-340-50-1 + Details
Name: | us-gaap_FiniteLivedIntangibleAssetsGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 926 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483154/926-20-50-5 + Details
Name: | us-gaap_FiniteLivedIntangibleAssetsNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, from an acquisition. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 805 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478072/944-805-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-1 + Details
Name: | us-gaap_FinitelivedIntangibleAssetsAcquired1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 24 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482548/350-20-55-24 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 805 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479328/805-10-50-8 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 805 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 41 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479303/805-10-55-41 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 805 -SubTopic 740 -Name Accounting Standards Codification -Section 55 -Paragraph 13 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478064/805-740-55-13 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 805 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 39 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479303/805-10-55-39 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 49 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482785/280-10-55-49 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 100 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-100 Reference 8: http://www.xbrl.org/2003/role/exampleRef -Topic 852 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481372/852-10-55-10 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(15)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482598/350-20-45-1 Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-1 Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (h) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-1 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(10)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 Reference 14: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 805 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479581/805-30-50-4 + Details
Name: | us-gaap_Goodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 24 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482548/350-20-55-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 805 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479581/805-30-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 805 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479581/805-30-50-4 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 805 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479581/805-30-50-1 + Details
Name: | us-gaap_GoodwillAcquiredDuringPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of foreign currency translation gain (loss) which increases (decreases) asset representing future economic benefit from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 805 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479581/805-30-50-4 + Details
Name: | us-gaap_GoodwillForeignCurrencyTranslationGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Name Accounting Standards Codification -Section 55 -Paragraph 40 -SubTopic 30 -Topic 350 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482640/350-30-55-40 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 10 -Name Accounting Standards Codification -Section S45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480265/350-10-S45-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 + Details
Name: | us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of foreign currency translation gain (loss) which increases (decreases) an asset, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 + Details
Name: | us-gaap_IndefiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482686/350-30-45-1 + Details
Name: | us-gaap_IntangibleAssetsNetExcludingGoodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=jhg_ClientRelationshipsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=jhg_InvestmentManagementAgreementsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=jhg_DefiniteLivedTrademarksMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis=jhg_InvestmentManagementAgreementsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_TrademarksMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |