XML 21 R57.htm IDEA: XBRL DOCUMENT v3.2.0.727

Derivative Financial Instruments - Schedule of Foreign Currency Forward Contracts (Details) € in Millions, £ in Millions, $ in Millions		3 Months Ended	6 Months Ended
		Jun. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2015 GBP (£)	Jun. 30, 2015 EUR (€)	Dec. 31, 2014 USD ($)
Foreign Exchange Forward Expected to Settle Quarterly | Counterparty C
Derivative
Foreign currency forward liabilities at fair value	[1]	$ 1.5	$ 1.5			$ 0.3
Foreign Exchange Forward Expected to Settle Quarterly | Counterparty C | Paying
Derivative
Notional amount | €					€ 15.8
Foreign Exchange Forward Expected to Settle Quarterly | Counterparty C | Receiving
Derivative
Notional amount		19.2	19.2
Foreign Exchange Forward Expected to Settle Monthly | Counterparty C
Derivative
Foreign currency forward liabilities at fair value	[1]	(0.2)	(0.2)			(0.8)
Foreign Exchange Forward Expected to Settle Monthly | Counterparty C | Paying
Derivative
Notional amount		7.5	7.5
Foreign Exchange Forward Expected to Settle Monthly | Counterparty C | Receiving
Derivative
Notional amount | £				£ 4.7
Foreign Exchange Forward Expected To Settle July Twenty Fifteen [Member] | Counterparty C
Derivative
Foreign currency forward liabilities at fair value	[1]	0.0	0.0			$ 0.0
Foreign Exchange Forward Expected To Settle July Twenty Fifteen [Member] | Counterparty C | Paying
Derivative
Notional amount | £				£ 2.0
Foreign Exchange Forward Expected To Settle July Twenty Fifteen [Member] | Counterparty C | Receiving
Derivative
Notional amount		3.1	3.1
Revenue
Derivative
Derivative, Gain on Derivative		1.1	1.4
Operating Expenses
Derivative
Derivative, Loss on Derivative		$ 0.5	$ 1.1
[1] The fair values of receivables and payables related to outstanding hedge contracts are presented within Other assets and Other liabilities, respectively. These amounts are expected to be reclassified into earnings within the next twelve months.

X

- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

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



-Publisher SEC



-Name Regulation S-X (SX)



-Number 210



-Article 12



-Section 13



-Sentence Column B

+ Details

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

+ References

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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 815



-SubTopic 10



-Section 45



-Paragraph 5



-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

+ Details

Name:	us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of increase in the fair value of derivatives recognized in the income statement.

+ References

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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 815



-SubTopic 10



-Section 50



-Paragraph 4C



-Subparagraph (a),(c),(d),(e)



-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959



Reference 2: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 815



-SubTopic 10



-Section 50



-Paragraph 4A



-Subparagraph (b)



-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5618551-113959

+ Details

Name:	us-gaap_DerivativeGainOnDerivative
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_DerivativeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of decrease in the fair value of derivatives recognized in the income statement.

+ References

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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 815



-SubTopic 10



-Section 50



-Paragraph 4A



-Subparagraph (b)



-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5618551-113959



Reference 2: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 815



-SubTopic 10



-Section 50



-Paragraph 4C



-Subparagraph (a),(c),(d),(e)



-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959

+ Details

Name:	us-gaap_DerivativeLossOnDerivative
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=amg_ForeignExchangeForwardExpectedtoSettleQuarterlyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_CounterpartyNameAxis=amg_CounterpartyCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PositionAxis=us-gaap_ShortMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PositionAxis=us-gaap_LongMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=amg_ForeignExchangeForwardExpectedtoSettleMonthlyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=amg_ForeignExchangeForwardExpectedToSettleJulyTwentyFifteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_AssetManagementIncomeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_OperatingExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: