Investments - Summary of Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Summary of Investment Holdings [Line Items]
Investments owned	$ 211,550	$ 273,418
Long-term incentive compensation obligations	45,800	63,800
Seed capital
Summary of Investment Holdings [Line Items]
Investments owned	287,300	379,000
Equity securities | Long-term incentive compensation-related
Summary of Investment Holdings [Line Items]
Investments owned	19,602	32,237
Equity securities | Seed capital
Summary of Investment Holdings [Line Items]
Investments owned	105,872	133,992
Equity securities | Other
Summary of Investment Holdings [Line Items]
Investments owned	12,629	18,243
Exchange-traded options
Summary of Investment Holdings [Line Items]
Investments owned	4,837	1,893
Investments in limited partnership hedge funds | Long-term incentive compensation-related
Summary of Investment Holdings [Line Items]
Investments owned	26,214	31,602
Investments in limited partnership hedge funds | Seed capital
Summary of Investment Holdings [Line Items]
Investments owned	16,013	19,318
Time deposits
Summary of Investment Holdings [Line Items]
Investments owned	17,298	21,024
Other
Summary of Investment Holdings [Line Items]
Investments owned	$ 9,085	$ 15,109