XML 69 R41.htm IDEA: XBRL DOCUMENT v3.3.0.814

Fair Value Measurements - Schedule of Quantitative Information used in Valuing Level 3 Liabilities (Details) - Discounted Cash Flow - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Contingent Payment Arrangements
Quantitative information for Level 3 Fair Value Measurements Liabilities
Fair value Liabilities	$ 7.1	$ 59.3
Contingent Payment Arrangements | Minimum
Quantitative information for Level 3 Fair Value Measurements Liabilities
Growth rate (as a percent)	(1.00%)	6.00%
Discount rate (as a percent)	16.00%	15.00%
Contingent Payment Arrangements | Maximum
Quantitative information for Level 3 Fair Value Measurements Liabilities
Growth rate (as a percent)	9.00%	6.00%
Discount rate (as a percent)	16.00%	15.00%
Affiliate Equity Repurchase Obligations
Quantitative information for Level 3 Fair Value Measurements Liabilities
Fair value Liabilities	$ 31.8	$ 21.5
Affiliate Equity Repurchase Obligations | Minimum
Quantitative information for Level 3 Fair Value Measurements Liabilities
Growth rate (as a percent)	3.00%	5.00%
Discount rate (as a percent)	15.00%	15.00%
Affiliate Equity Repurchase Obligations | Maximum
Quantitative information for Level 3 Fair Value Measurements Liabilities
Growth rate (as a percent)	10.00%	9.00%
Discount rate (as a percent)	16.00%	16.00%

X

- Definition

Represents percentage of assumed growth rates, used as an input to measure fair value.

+ References

No definition available.

+ Details

Name:	amg_FairValueInputsGrowthRates
Namespace Prefix:	amg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 820



-SubTopic 10



-Section 50



-Paragraph 2



-Subparagraph (bbb)



-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueInputsDiscountRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

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_FairValueInputsLiabilitiesQuantitativeInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Fair value of financial and nonfinancial obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 820



-SubTopic 10



-Section 50



-Paragraph 2



-Subparagraph (a)



-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

Name:	us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Details

Name:	us-gaap_ValuationTechniqueAxis=amg_DiscountedCashFlowValuationTechniqueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=amg_ContingentPaymentArrangementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=amg_ObligationsToRelatedPartiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: