Fair Value Measurements for Operating Entities and Consolidated Funds - Unobservable Input Roll Forward (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021		Dec. 31, 2021	Dec. 31, 2020
Preferred Stock
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Asset Value		$ 169,701	$ 56,477		$ 122,631	$ 59,967
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases		3,441	1,859
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales		1,100	4,651
Realized and unrealized gains (losses), asset		44,729	(698)
Change in Unrealized Gain (Loss), instruments still held, asset	[1]	44,729	(698)
Common Stock
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Asset Value		39,831	22,706		32,658	23,786
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		0	5,353	[2]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases		2,018	3,226
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales		33	1,387
Realized and unrealized gains (losses), asset		5,188	2,434
Change in Unrealized Gain (Loss), instruments still held, asset	[1]	5,188	1,679
Convertible Bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Asset Value		5,250	3,137		5,250	6,040
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases		0	1,050
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales		0	3,930
Realized and unrealized gains (losses), asset		0	(23)
Change in Unrealized Gain (Loss), instruments still held, asset	[1]	0	(23)
Corporate Bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Asset Value		2,426	136		2,419	135
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases		0	70
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales		0	49
Realized and unrealized gains (losses), asset		7	(20)
Change in Unrealized Gain (Loss), instruments still held, asset	[1]	7	(49)
Options (held long)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Asset Value		228	241		234	251
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales		0	0
Realized and unrealized gains (losses), asset		(6)	(10)
Change in Unrealized Gain (Loss), instruments still held, asset	[1]	(6)	(10)
Warrants and Rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Asset Value		18,557	7,924		15,403	6,547
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases		414	3,406
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales		0	1,206
Realized and unrealized gains (losses), asset		2,740	(823)
Change in Unrealized Gain (Loss), instruments still held, asset	[1]	2,740	(895)
Trade Claims
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Asset Value		4,840	5,905		3,496	8,713
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases		1,666	1,378
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales		615	4,216
Realized and unrealized gains (losses), asset		293	30
Change in Unrealized Gain (Loss), instruments still held, asset	[1]	293	(1,021)
Term Loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Asset Value			12,424			12,623
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3			0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3			0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases			322
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales			0
Realized and unrealized gains (losses), asset			(521)
Change in Unrealized Gain (Loss), instruments still held, asset			(521)
Private Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Asset Value		550	1,085		410	642
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases		353	443
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales		250	0
Realized and unrealized gains (losses), asset		37	0
Change in Unrealized Gain (Loss), instruments still held, asset		37	0
Consolidated Funds | Common Stock
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Asset Value			2,951			2,951
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3			0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3			0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases			0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales			0
Realized and unrealized gains (losses), asset			0
Change in Unrealized Gain (Loss), instruments still held, asset	[1]		0
Consolidated Funds | Warrants and Rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Asset Value			5,329			5,806
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3			0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3			0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases			0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales			670
Realized and unrealized gains (losses), asset			193
Change in Unrealized Gain (Loss), instruments still held, asset	[1]		(477)
Options (held short)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Liability Value		3,079	3,297		3,419	3,915
Liability, Transfers In		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3		0	0
Liability, Purchases		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Sales		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings		340	618
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss)	[1]	(340)	(618)
Contingent liability payable
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Liability Value		57,339	19,579		$ 62,223	37,952
Liability, Transfers In		0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3		0	0
Liability, Purchases		0	(11,312)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Sales		10,076	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings		(5,192)	7,061
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss)	[1]	$ 5,192	(7,061)
Corporate Bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Asset Value			415
Balance Liability Value						704
Liability, Transfers In			0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3			0
Liability, Purchases			0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Sales			(289)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings			0
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss)	[1]		0
Government Debt Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance Asset Value			522
Balance Liability Value						$ 1,500
Liability, Transfers In			0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3			0
Liability, Purchases			0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Sales			(1,278)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings			300
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss)	[1]		$ 87

[1] Unrealized gains/losses are reported in Investment income - Securities principal transactions, net in the accompanying condensed consolidated statements of operations

[2] The entity in which the Company is invested completed an initial public offering