Investments - Summary of Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Summary of Investment Holdings [Line Items]
Investments owned	$ 273,418	$ 253,375
Seed capital
Summary of Investment Holdings [Line Items]
Investments owned	379,000	310,300
Equity securities: | Long-term incentive compensation-related
Summary of Investment Holdings [Line Items]
Investments owned	32,237	34,351
Equity securities: | Seed capital
Summary of Investment Holdings [Line Items]
Investments owned	133,992	75,766
Equity securities: | Other
Summary of Investment Holdings [Line Items]
Investments owned	18,243	55,439
Exchange-traded options
Summary of Investment Holdings [Line Items]
Investments owned	1,893	7,527
Investments in limited partnership hedge funds: | Long-term incentive compensation-related
Summary of Investment Holdings [Line Items]
Investments owned	31,602	25,762
Investments in limited partnership hedge funds: | Seed capital
Summary of Investment Holdings [Line Items]
Investments owned	19,318	16,646
Time deposits
Summary of Investment Holdings [Line Items]
Investments owned	21,024	18,602
Other
Summary of Investment Holdings [Line Items]
Investments owned	$ 15,109	$ 19,282