Segment Reporting - Segment Breakout (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Information
Total revenues		$ 2,112,799	$ 1,755,926	$ 1,163,570
Depreciation and Amortization		19,004	22,677	20,460
Income tax expense (benefit)		102,039	90,373	14,853
Interest and Dividend Expense		211,387	187,725	168,628
Dividend expense		6,800	8,100	8,800
Dividend revenue		26,000	17,300	9,200
Consolidated Funds
Segment Information
Interest and Dividend Expense		0	2,064	4,602
Dividend expense		0	700	1,000
Dividend revenue		0	2,500	3,000
Operating Segments
Segment Information
Non-Interest Revenue	[1]	1,919,569	1,583,106	991,088
Interest Revenue		193,221	170,128	165,727
Total revenues		2,112,799	1,755,926	1,163,570
Operating Segments | Consolidated Funds
Segment Information
Interest Revenue		9	2,692	6,755
OpCo | Operating Segments
Segment Information
Non-Interest Revenue		1,917,406	1,564,710	981,131
Interest Revenue		192,756	169,358	165,443
Total revenues		2,110,162	1,736,751	1,153,320
Interest Expense		199,570	173,537	155,974
Depreciation and Amortization		18,982	22,655	20,424
Income tax expense (benefit)		103,149	90,373	14,853
OpCo | Operating Segments | Consolidated Funds
Segment Information
Interest Revenue		0	2,683	6,746
Interest Expense		0	1,376	3,553
Asset Co | Operating Segments
Segment Information
Non-Interest Revenue		2,163	18,396	9,957
Interest Revenue		465	770	284
Total revenues		2,637	19,175	10,250
Interest Expense		5,035	6,120	3,835
Depreciation and Amortization		22	22	36
Income tax expense (benefit)		(1,110)	0	0
Asset Co | Operating Segments | Consolidated Funds
Segment Information
Interest Revenue		9	9	9
Interest Expense		$ 0	$ 0	$ 0

[1] Includes dividend revenue of $26.0 million, $17.3 million and $9.2 million for the years ended December 31, 2021, 2020, and 2019, respectively. In addition, includes dividend revenue, consolidated funds, of $0.0 million and $2.5 million and $3.0 million for the years ended December 31, 2021, 2020, and 2019, respectively.