XML 103 R51.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Goodwill and Acquired Client Relationships (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2012
Goodwill and Acquired Client Relationships |
Schedule of changes in goodwill |
|  | Institutional |  | Mutual Fund |  | High Net Worth |  | Total |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Balance, as of December 31, 2010 |  | $ | 1,073.6 |  | $ | 786.7 |  | $ | 261.6 |  | $ | 2,121.9 |
Goodwill acquired |  |  | 0.1 |  |  | — |  |  | 1.3 |  |  | 1.4 |
Foreign currency translation |  |  | (2.3 | ) |  | (1.7 | ) |  | (2.0 | ) |  | (6.0 | )
Balance, as of December 31, 2011 |  | $ | 1,071.4 |  | $ | 785.0 |  | $ | 260.9 |  | $ | 2,117.3 |
Goodwill acquired |  |  | 0.3 |  |  | 151.3 |  |  | 74.3 |  |  | 225.9 |
Foreign currency translation |  |  | 6.8 |  |  | 3.2 |  |  | 2.0 |  |  | 12.0 |
Balance, as of December 31, 2012 |  | $ | 1,078.5 |  | $ | 939.5 |  | $ | 337.2 |  | $ | 2,355.2 |
Schedule of changes in and the components of acquired client relationships |
|  | Acquired Client Relationships |
--- | --- | --- | ---
|  | Definite-lived |  | Indefinite-lived |  | Total |
|  | Gross Book Value |  | Accumulated Amortization |  | Net Book Value |  | Net Book Value |  | Net Book Value |
Balance, as of December 31, 2010 |  | $ | 971.1 |  | $ | (228.5 | ) | $ | 742.6 |  | $ | 678.0 |  | $ | 1,420.6 |
New Investments |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |
Amortization and impairments |  |  | — |  |  | (88.5 | ) |  | (88.5 | ) |  | (9.2 | ) |  | (97.7 | )
Foreign currency translation |  |  | (0.6 | ) |  | — |  |  | (0.6 | ) |  | (1.2 | ) |  | (1.8 | )
Balance, as of December 31, 2011 |  | $ | 970.5 |  | $ | (317.0 | ) | $ | 653.5 |  | $ | 667.6 |  | $ | 1,321.1 |
New Investments |  |  | 131.1 |  |  | — |  |  | 131.1 |  |  | 321.5 |  |  | 452.6 |
Amortization and impairments |  |  | — |  |  | (97.8 | ) |  | (97.8 | ) |  | (102.2 | ) |  | (200.0 | )
Foreign currency translation |  |  | 1.1 |  |  | — |  |  | 1.1 |  |  | 10.7 |  |  | 11.8 |
Transfers and other |  |  | 6.9 |  |  | 31.3 |  |  | 38.2 |  |  | (38.2 | ) |  | — |
Balance, as of December 31, 2012 |  | $ | 1,109.6 |  | $ | (383.5 | ) | $ | 726.1 |  | $ | 859.4 |  | $ | 1,585.5 |

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
- 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://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 45 -Subparagraph c -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 47 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13854-109267 Reference 4: 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 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 45 -Subparagraph e -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_ScheduleOfGoodwillTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration