XML 72 R50.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Affiliate Equity (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2018
Affiliate Equity |
Schedule of Affiliate Equity Compensation Expense | The following table presents Affiliate equity compensation expense:
| For the Years Ended December 31,
| 2016 |  | 2017 |  | 2018
Controlling interest | $ | 10.0 |  |  | $ | 13.2 |  |  | $ | 16.7 |
Non-controlling interests | 31.2 |  |  | 36.8 |  |  | 39.7 |
Total | $ | 41.2 |  |  | $ | 50.0 |  |  | $ | 56.4 |
Schedule of Affiliate Equity Unrecognized Compensation Expense | The following table presents unrecognized Affiliate equity compensation expense:
Year | Controlling Interest |  | Remaining Life |  | Non-controlling Interests |  | Remaining Life
2016 | $ | 31.3 |  |  | 4 years |  | $ | 70.7 |  |  | 5 years
2017 | 33.3 |  |  | 5 years |  | 95.9 |  |  | 6 years
2018 | 38.7 |  |  | 5 years |  | 118.3 |  |  | 6 years
Schedule of the Effect of Changes in the Company's Ownership Interest in its Affiliates on the Controlling Interest's Equity | While the Company presents the current redemption value of Affiliate equity within Redeemable non-controlling interests with changes in the current redemption value increasing or decreasing the controlling interest’s equity over time, the following table presents the cumulative effect that ownership changes had on the controlling interest’s equity related only to Affiliate equity transactions that settled during the periods:
|  | For the Years Ended December 31,
|  | 2016 |  | 2017 |  | 2018
Net income (controlling interest) |  | $ | 472.8 |  |  | $ | 689.5 |  |  | $ | 243.6 |
Increase (decrease) in controlling interest paid-in capital from Affiliate equity issuances |  | 1.6 |  |  | (1.0 | ) |  | (5.0 | )
Decrease in controlling interest paid-in capital from Affiliate equity repurchases |  | (38.0 | ) |  | (116.2 | ) |  | (67.9 | )
Net income (controlling interest) including the net impact of Affiliate equity transactions |  | $ | 436.4 |  |  | $ | 572.3 |  |  | $ | 170.7 |

X
- Definition -- None. No documentation exists for this element. -- + References No definition available. + Details
Name: | amg_AffiliateEquityDisclosureAbstract
Namespace Prefix: | amg_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents a schedule of net income (loss) attributable to the entity and net transfers to non-controlling interest. + References No definition available. + Details
Name: | amg_ScheduleOfNetIncomeLossAttributableToEntityAndNetTransfersWithNoncontrollingInterestTableTextBlock
Namespace Prefix: | amg_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Summary of Affiliate Equity Compensation Expense [Table Text Block] + References No definition available. + Details
Name: | amg_SummaryofAffiliateEquityCompensationExpenseTableTextBlock
Namespace Prefix: | amg_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Summary of Affiliate Equity Unrecognized Compensation Expense [Table Text Block] + References No definition available. + Details
Name: | amg_SummaryofAffiliateEquityUnrecognizedCompensationExpenseTableTextBlock
Namespace Prefix: | amg_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration