XML 64 R48.htm IDEA: XBRL DOCUMENT
v3.19.1

Investments in Affiliates and Affiliate Sponsored Investment Products - Affiliated Sponsored Investment Products (Details) - Affiliate sponsored investment products - USD ($) $ in Millions | Mar. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Variable Interest Entities |  |
Unconsolidated VIE Net Assets | $ 2,208.5 | $ 2,216.5
Carrying Value and Maximum Exposure to Loss | $ 0.6 | $ 1.1

X
- Definition The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=108788376&loc=d3e5747-111685 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph b -URI http://asc.fasb.org/extlink&oid=108788376&loc=d3e5728-111685 + Details
Name: | us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_VariableInterestEntityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Net carrying amount of the assets and liabilities in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), when the reporting entity is not the VIE's primary beneficiary. + References No definition available. + Details
Name: | us-gaap_VariableInterestEntityNonconsolidatedCarryingAmountAssetsAndLiabilitiesNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=amg_SponsoredInvestmentFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |