XML 58 R32.htm IDEA: XBRL DOCUMENT
v3.20.2

Goodwill and Acquired Client Relationships (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract] |
Schedule of Changes in Goodwill | The following tables present the changes in the Company’s consolidated Affiliates’ Goodwill and components of Acquired client relationships (net):
|  | Goodwill
Balance, as of December 31, 2019 |  | $ | 2,651.7 |
Foreign currency translation |  | (24.1 | )
Balance, as of June 30, 2020 |  | $ | 2,627.6 |
Schedule of Changes in the Components of Acquired Client Relationships |
| 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, 2019 | $ | 1,248.8 |  |  | $ | (1,039.0 | ) |  | $ | 209.8 |  |  | $ | 972.2 |  |  | $ | 1,182.0 |
Intangible amortization and impairments | — |  |  | (55.7 | ) |  | (55.7 | ) |  | (45.8 | ) |  | (101.5 | )
Foreign currency translation | (7.3 | ) |  | 4.7 |  |  | (2.6 | ) |  | (25.6 | ) |  | (28.2 | )
Balance, as of June 30, 2020 | $ | 1,241.5 |  |  | $ | (1,090.0 | ) |  | $ | 151.5 |  |  | $ | 900.8 |  |  | $ | 1,052.3 |

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: | nonnum: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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=121556970&loc=d3e13854-109267 + Details
Name: | us-gaap_ScheduleOfGoodwillTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration