XML 44 R32.htm IDEA: XBRL DOCUMENT
v3.25.1

Goodwill and Acquired Client Relationships (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2025
Goodwill and Intangible Assets Disclosure [Abstract] |
Schedule of Changes in Goodwill | The following table presents the changes in the Company’s consolidated Affiliates’ Goodwill:
|  | Goodwill
Balance, as of December 31, 2024 |  | $2,504.9
Foreign currency translation |  | 7.6
Balance, as of March 31, 2025 |  | $2,512.5
Schedule of Changes in the Components of Acquired Client Relationships | The following table presents the changes in the Company’s components of Acquired client relationships (net):
| Acquired Client Relationships (Net)
| Definite-lived |  | Indefinite-lived |  | Total
| Gross Book Value |  | Accumulated Amortization |  | Net Book Value |  | Net Book Value |  | Net Book Value
Balance, as of December 31, 2024 | $1,255.5 |  | $(1,075.2) |  | $180.3 |  | $1,597.5 |  | $1,777.8
Intangible amortization and impairments | — |  | (6.3) |  | (6.3) |  | (77.0) |  | (83.3)
Foreign currency translation | 3.8 |  | (3.9) |  | (0.1) |  | 9.5 |  | 9.4
Balance, as of March 31, 2025 | $1,259.3 |  | $(1,085.4) |  | $173.9 |  | $1,530.0 |  | $1,703.9

X
- Definition Tabular disclosure of intangibles assets, in total and by major class, including the gross carrying amount and accumulated amortization. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company. + References No definition available. + Details
Name: | amg_ScheduleOfIntangibleAssetsByMajorClassTableTextBlock
Namespace Prefix: | amg_
Data Type: | dtr-types1:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule. + 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/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 3: 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 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-1 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -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 6: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-1 Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-1 Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-1 Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef -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 10: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (g) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-1 Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-1A Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 350 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482573/350-20-50-2 + Details
Name: | us-gaap_ScheduleOfGoodwillTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration