Investments of Operating Entities and Consolidated Funds - Operating Entities - Securities Sold, Not Yet Purchased (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Investments Sold, Not yet Purchased [Line Items]
Securities sold, not yet purchased, at fair value	$ 1,201,448,000	$ 728,115,000
Common Stock
Investments Sold, Not yet Purchased [Line Items]
Securities sold, not yet purchased, at fair value	1,192,396,000	699,894,000
Corporate Bonds
Investments Sold, Not yet Purchased [Line Items]
Securities sold, not yet purchased, at fair value	37,000	11,358,000
Government Debt Securities
Investments Sold, Not yet Purchased [Line Items]
Securities sold, not yet purchased, at fair value	0	1,500,000
Preferred Stock
Investments Sold, Not yet Purchased [Line Items]
Securities sold, not yet purchased, at fair value	9,009,000	6,589,000
Warrants and Rights
Investments Sold, Not yet Purchased [Line Items]
Securities sold, not yet purchased, at fair value	$ 6,000	$ 8,774,000