XML 27 R47.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Business Combinations Schedule of purchase price allocation for investments (Details) (USD $) In Millions, unless otherwise specified |  |  | 0 Months Ended
--- | --- | --- | ---
Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 Southern Sun Asset Management, LLC [Member]
Business Acquisition [Line Items] |  |  |
Consideration paid |  |  | $ 109.9
Non-controlling interests |  |  | 78.9
Enterprise value |  |  | 188.8
Acquired client relationships |  |  | 126.9
Tangible assets, net |  |  | 6.2
Goodwill | 2,385.9 | 2,341.7 | 55.7
Total |  |  | $ 188.8

X
- Definition Represents the amount of Consideration Paid, Deferred Consideration, noncontrolling interest and Contingent payment obligations related to acquisition. + References No definition available. + Details
Name: | amg_BusinessAcquisitionEnterpriseValue
Namespace Prefix: | amg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Business Combination, Recognized Identifiable Assets Acquired, Tangible Assets + References No definition available. + Details
Name: | amg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredTangibleAssets
Namespace Prefix: | amg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents the fair value of the noncontrolling interest in the acquiree at the acquisition date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (e)(1) -URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of identifiable intangible assets recognized as of the acquisition date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 55 -Paragraph 37 -URI http://asc.fasb.org/extlink&oid=25498275&loc=d3e2207-128464 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 + Details
Name: | us-gaap_Goodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireBusinessesGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration