INVESTMENTS - Net Gains (Losses) from Investment Activities of Consolidated Funds (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Gain (Loss) on Securities [Line Items]
Net Realized Gain (Loss) on Investments	$ (89,225)	$ 6,044
Net Change in Unrealized Appreciation (Depreciation) on Investments	128,359	53,868
Consolidated Funds | Not Designated as Hedging Instrument
Gain (Loss) on Securities [Line Items]
Net Realized Gain (Loss) on Investments	(89,225)	6,044
Net Change in Unrealized Appreciation (Depreciation) on Investments	128,359	53,868
Consolidated Funds | Investments and other financial instruments | Not Designated as Hedging Instrument
Gain (Loss) on Securities [Line Items]
Net Realized Gain (Loss) on Investments	(90,055)	4,967
Net Change in Unrealized Appreciation (Depreciation) on Investments	201,267	47,372
Consolidated Funds | CLO liabilities | Not Designated as Hedging Instrument
Gain (Loss) on Securities [Line Items]
Net Realized Gain (Loss) on Investments	(2,115)	1,928
Net Change in Unrealized Appreciation (Depreciation) on Investments	(45,844)	4,563
Consolidated Funds | Foreign-currency forward contracts | Not Designated as Hedging Instrument
Gain (Loss) on Securities [Line Items]
Net Realized Gain (Loss) on Investments	956	(1,373)
Net Change in Unrealized Appreciation (Depreciation) on Investments	2,928	2,706
Consolidated Funds | Total-return and interest-rate swaps | Not Designated as Hedging Instrument
Gain (Loss) on Securities [Line Items]
Net Realized Gain (Loss) on Investments	(3,984)	0
Net Change in Unrealized Appreciation (Depreciation) on Investments	(32,833)	(34)
Consolidated Funds | Options and futures | Not Designated as Hedging Instrument
Gain (Loss) on Securities [Line Items]
Net Realized Gain (Loss) on Investments	5,973	522
Net Change in Unrealized Appreciation (Depreciation) on Investments	1,983	199
Consolidated Funds | Warrants | Not Designated as Hedging Instrument
Gain (Loss) on Securities [Line Items]
Net Realized Gain (Loss) on Investments	0	0
Net Change in Unrealized Appreciation (Depreciation) on Investments	$ 858	$ (938)