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Equity Method Investments in Affiliates - Additional Information (Details) shares in Thousands, $ in Millions | 3 Months Ended | 9 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Sep. 30, 2022 USD ($) affiliate | Mar. 31, 2022 USD ($) shares | Sep. 30, 2021 USD ($) | Sep. 30, 2022 USD ($) affiliate | Sep. 30, 2021 USD ($) | Oct. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) affiliate | Dec. 31, 2016 USD ($)
Estimated Future Amortization Expense of Finite-Lived Intangibles |  |  |  |  |  |  |  |
Number of affiliates | affiliate | 21 |  |  | 21 |  |  | 21 |
Equity method investments | $ 95.5 |  |  | $ 95.5 |  |  | $ 111.4 |
Baring Private Equity Asia (“BPEA”) |  |  |  |  |  |  |  |
Estimated Future Amortization Expense of Finite-Lived Intangibles |  |  |  |  |  |  |  |
Equity method investments | 132.7 |  |  | 132.7 |  |  |  | $ 187.5
Private Markets Firm | Subsequent Event |  |  |  |  |  |  |  |
Estimated Future Amortization Expense of Finite-Lived Intangibles |  |  |  |  |  |  |  |
Assets under management |  |  |  |  |  | $ 4,000.0 |  |
Baring Private Equity Asia (“BPEA”) | EQT AB (“EQT”) |  |  |  |  |  |  |  |
Estimated Future Amortization Expense of Finite-Lived Intangibles |  |  |  |  |  |  |  |
Expected cash proceeds |  | $ 240.0 |  |  |  |  |  |
Expected equity interest issuable, number of shares (in shares) | shares |  | 28,680 |  |  |  |  |  |
Percentage of shares restricted |  | 0.25 |  |  |  |  |  |
Term of restricted shares |  | 6 months |  |  |  |  |  |
Acquired Client Relationships |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |
Amortization of Intangible Assets |  |  |  | 36.9 |  |  |  |
Estimated Future Amortization Expense of Finite-Lived Intangibles |  |  |  |  |  |  |  |
Finite-lived intangible, future amortization expense, remainder of fiscal year | 12.0 |  |  | 12.0 |  |  |  |
Finite-lived intangible, future amortization expense in year one | 50.0 |  |  | 50.0 |  |  |  |
Finite-lived intangible, future amortization expense in year two | 35.0 |  |  | 35.0 |  |  |  |
Finite-lived intangible, future amortization expense in year three | 35.0 |  |  | 35.0 |  |  |  |
Finite-lived intangible, future amortization expense in year four | 35.0 |  |  | 35.0 |  |  |  |
Finite-lived intangible, future amortization expense in year five | 35.0 |  |  | 35.0 |  |  |  |
Equity Method Investee | Acquired Client Relationships |  |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |  |
Amortization of Intangible Assets | 31.4 |  | $ 29.3 | 89.3 | $ 93.8 |  |  |
Estimated Future Amortization Expense of Finite-Lived Intangibles |  |  |  |  |  |  |  |
Finite-lived intangible, future amortization expense, remainder of fiscal year | 25.0 |  |  | 25.0 |  |  |  |
Finite-lived intangible, future amortization expense in year one | 80.0 |  |  | 80.0 |  |  |  |
Finite-lived intangible, future amortization expense in year two | 50.0 |  |  | 50.0 |  |  |  |
Finite-lived intangible, future amortization expense in year three | 50.0 |  |  | 50.0 |  |  |  |
Finite-lived intangible, future amortization expense in year four | 40.0 |  |  | 40.0 |  |  |  |
Finite-lived intangible, future amortization expense in year five | $ 40.0 |  |  | $ 40.0 |  |  |  |

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