Segment Reporting (Details) $ in Thousands		3 Months Ended
		Mar. 31, 2021 USD ($) segment	Mar. 31, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment		2
Reconciliation to U.S. GAAP Company's Economic Income (Loss)
Preferred stock dividends		$ 1,698	$ 1,698
Amortization of (discount)/premium on convertible debt		776	1,109
Bargain Purchase Gain, net of tax		3,855	0
Income tax expense (benefit)		54,428	(1,173)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest		206,494	(73,284)
Segment Information
Total revenues		754,323	196,723
Depreciation and Amortization		4,354	5,442
Income tax expense (benefit)		54,428	(1,173)
Interest and Dividend Expense		57,641	38,792
Dividend expense		2,600	3,500
Dividend revenue		8,100	8,300
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		152,066	(72,111)
Consolidated Funds
Segment Information
Interest and Dividend Expense		0	1,252
Dividend expense			200
Dividend revenue		2,600	3,500
Operating Segments
Segment Information
Non-Interest Revenue	[1]	703,014	162,428
Interest Revenue		51,307	33,716
Total revenues		754,323	196,723
Operating Segments | Consolidated Funds
Segment Information
Interest Revenue		2	579
Adjustments
Reconciliation to U.S. GAAP Company's Economic Income (Loss)
Noncontrolling Interest (Adjusted)		4,562	(62,188)
Preferred stock dividends		1,698	1,698
Amortization of (discount)/premium on convertible debt		(776)	(1,110)
Acquisition related amounts		(238)	0
Contingent Consideration Payable		6,798	895
Debt extinguishment gain (loss)		(4,538)	0
Bargain Purchase Gain, net of tax		3,855	0
Income tax expense (benefit)		(1,677)	1,173
Segment Information
Income tax expense (benefit)		(1,677)	1,173
OpCo | Operating Segments
Reconciliation to U.S. GAAP Company's Economic Income (Loss)
Economic Income		143,858	3,650
Income tax expense (benefit)		55,085
Segment Information
Non-Interest Revenue		704,682	173,123
Interest Revenue		51,104	33,666
Total revenues		755,786	207,366
Interest Expense		53,803	33,639
Depreciation and Amortization		4,349	5,436
Income tax expense (benefit)		55,085
OpCo | Operating Segments | Consolidated Funds
Segment Information
Interest Revenue		0	577
Interest Expense		0	1,061
Asset Co | Operating Segments
Reconciliation to U.S. GAAP Company's Economic Income (Loss)
Economic Income		(1,476)	(16,229)
Income tax expense (benefit)		(657)
Segment Information
Non-Interest Revenue		(1,668)	(10,695)
Interest Revenue		203	50
Total revenues		(1,463)	(10,643)
Interest Expense		1,275	1,689
Depreciation and Amortization		5	6
Income tax expense (benefit)		(657)
Asset Co | Operating Segments | Consolidated Funds
Segment Information
Interest Revenue		2	2
Interest Expense		$ 0	$ 0

[1] Includes dividend revenue of $8.1 million and $8.3 million for the three months ended March 31, 2021 and 2020, respectively. In addition, includes dividend revenue, consolidated funds, of $2.6 million and $3.5 million for the three months ended March 31, 2021 and 2020, respectively.