FAIR VALUE - Consolidated Funds Valuation of Investments and Other Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total derivatives	$ 11,014	$ 24,077
Derivative liabilities	(23,379)	(35,862)
Consolidated Funds
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	4,527,442	3,908,613
Total derivatives	9,116	10,737
Derivative liabilities	(21,242)	(24,022)
Consolidated Funds | Options and futures
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total derivatives	797	279
Derivative liabilities	(1,428)
Consolidated Funds | Level III
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	2,956,992	2,390,273
Consolidated Funds | Fair Value, Measurements, Recurring
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	4,527,442	3,908,613
Total derivatives	9,116	10,737
Total assets	4,536,558	3,919,350
Derivative liabilities	(21,242)	(24,022)
Total liabilities	(21,242)	(24,022)
Consolidated Funds | Fair Value, Measurements, Recurring | Foreign-currency forward contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total derivatives	2,189	9,758
Derivative liabilities	(19,486)	(16,356)
Consolidated Funds | Fair Value, Measurements, Recurring | Swaps
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total derivatives	6,130	700
Derivative liabilities	(328)	(7,666)
Consolidated Funds | Fair Value, Measurements, Recurring | Options and futures
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total derivatives	797	279
Derivative liabilities	(1,428)	0
Consolidated Funds | Fair Value, Measurements, Recurring | Corporate debt – bank debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	1,722,409	1,114,494
Consolidated Funds | Fair Value, Measurements, Recurring | Corporate debt – all other
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	1,050,358	984,344
Consolidated Funds | Fair Value, Measurements, Recurring | Equities – common stock
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	1,046,176	1,038,449
Consolidated Funds | Fair Value, Measurements, Recurring | Equities – preferred stock
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	619,824	696,855
Consolidated Funds | Fair Value, Measurements, Recurring | Real estate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	88,675	74,471
Consolidated Funds | Fair Value, Measurements, Recurring | Level I
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	207,274	307,113
Total derivatives	6,340	279
Total assets	213,614	307,392
Derivative liabilities	(1,428)	(7,666)
Total liabilities	(1,428)	(7,666)
Consolidated Funds | Fair Value, Measurements, Recurring | Level I | Foreign-currency forward contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total derivatives	0	0
Derivative liabilities	0	0
Consolidated Funds | Fair Value, Measurements, Recurring | Level I | Swaps
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total derivatives	5,543	0
Derivative liabilities	0	(7,666)
Consolidated Funds | Fair Value, Measurements, Recurring | Level I | Options and futures
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total derivatives	797	279
Derivative liabilities	(1,428)	0
Consolidated Funds | Fair Value, Measurements, Recurring | Level I | Corporate debt – bank debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	0	0
Consolidated Funds | Fair Value, Measurements, Recurring | Level I | Corporate debt – all other
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	0	0
Consolidated Funds | Fair Value, Measurements, Recurring | Level I | Equities – common stock
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	206,134	226,862
Consolidated Funds | Fair Value, Measurements, Recurring | Level I | Equities – preferred stock
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	1,140	80,251
Consolidated Funds | Fair Value, Measurements, Recurring | Level I | Real estate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	0	0
Consolidated Funds | Fair Value, Measurements, Recurring | Level II
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	1,363,176	1,211,227
Total derivatives	2,776	10,458
Total assets	1,365,952	1,221,685
Derivative liabilities	(19,814)	(16,356)
Total liabilities	(19,814)	(16,356)
Consolidated Funds | Fair Value, Measurements, Recurring | Level II | Foreign-currency forward contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total derivatives	2,189	9,758
Derivative liabilities	(19,486)	(16,356)
Consolidated Funds | Fair Value, Measurements, Recurring | Level II | Swaps
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total derivatives	587	700
Derivative liabilities	(328)	0
Consolidated Funds | Fair Value, Measurements, Recurring | Level II | Options and futures
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total derivatives	0	0
Derivative liabilities	0	0
Consolidated Funds | Fair Value, Measurements, Recurring | Level II | Corporate debt – bank debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	459,775	411,997
Consolidated Funds | Fair Value, Measurements, Recurring | Level II | Corporate debt – all other
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	873,035	764,841
Consolidated Funds | Fair Value, Measurements, Recurring | Level II | Equities – common stock
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	30,366	34,389
Consolidated Funds | Fair Value, Measurements, Recurring | Level II | Equities – preferred stock
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	0	0
Consolidated Funds | Fair Value, Measurements, Recurring | Level II | Real estate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	0	0
Consolidated Funds | Fair Value, Measurements, Recurring | Level III
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	2,956,992	2,390,273
Total derivatives	0	0
Total assets	2,956,992	2,390,273
Derivative liabilities	0	0
Total liabilities	0	0
Consolidated Funds | Fair Value, Measurements, Recurring | Level III | Foreign-currency forward contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total derivatives	0	0
Derivative liabilities	0	0
Consolidated Funds | Fair Value, Measurements, Recurring | Level III | Swaps
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total derivatives	0	0
Derivative liabilities	0	0
Consolidated Funds | Fair Value, Measurements, Recurring | Level III | Options and futures
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total derivatives	0	0
Derivative liabilities	0	0
Consolidated Funds | Fair Value, Measurements, Recurring | Level III | Corporate debt – bank debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	1,262,634	702,497
Consolidated Funds | Fair Value, Measurements, Recurring | Level III | Corporate debt – all other
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	177,323	219,503
Consolidated Funds | Fair Value, Measurements, Recurring | Level III | Equities – common stock
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	809,676	777,198
Consolidated Funds | Fair Value, Measurements, Recurring | Level III | Equities – preferred stock
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	618,684	616,604
Consolidated Funds | Fair Value, Measurements, Recurring | Level III | Real estate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total investments	$ 88,675	$ 74,471