FAIR VALUE MEASUREMENTS - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	$ 605,080	$ 598,048
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	$ 523	$ 3,787
Assets, fair value disclosure	635,456	632,483
Securities sold, not yet purchased	4,076	4,529
Contingent consideration liability	2,274	4,495
Derivative liabilities	222,587	274,280
Total of liabilities measured at fair value	228,937	283,304
Fair Value, Measurements, Recurring | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	1,704
Fair Value, Measurements, Recurring | Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	58,530	58,623
Fair Value, Measurements, Recurring | Alternative investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	50,001	59,230
Fair Value, Measurements, Recurring | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	116,531	147,173
Fair Value, Measurements, Recurring | Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	330,496	289,610
Fair Value, Measurements, Recurring | Private equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	47,818	43,412
Fair Value, Measurements, Recurring | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Deposits with banks and short-term investments	29,753	24,666
Fair Value, Measurements, Recurring | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents		5,982
Restricted cash	100
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	0	0
Assets, fair value disclosure	530,750	517,693
Securities sold, not yet purchased	4,076	4,529
Contingent consideration liability	0	0
Derivative liabilities	0	0
Total of liabilities measured at fair value	4,076	4,529
Fair Value, Measurements, Recurring | Level 1 | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	1,300
Fair Value, Measurements, Recurring | Level 1 | Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	57,845	58,034
Fair Value, Measurements, Recurring | Level 1 | Alternative investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	6,825	10,763
Fair Value, Measurements, Recurring | Level 1 | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	104,795	129,004
Fair Value, Measurements, Recurring | Level 1 | Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	330,132	289,244
Fair Value, Measurements, Recurring | Level 1 | Private equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring | Level 1 | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Deposits with banks and short-term investments	29,753	24,666
Fair Value, Measurements, Recurring | Level 1 | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents		5,982
Restricted cash	100
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	523	3,787
Assets, fair value disclosure	12,963	22,269
Securities sold, not yet purchased	0	0
Contingent consideration liability	0	0
Derivative liabilities	222,587	274,280
Total of liabilities measured at fair value	222,587	274,280
Fair Value, Measurements, Recurring | Level 2 | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	404
Fair Value, Measurements, Recurring | Level 2 | Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring | Level 2 | Alternative investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring | Level 2 | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	11,733	18,166
Fair Value, Measurements, Recurring | Level 2 | Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	303	316
Fair Value, Measurements, Recurring | Level 2 | Private equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring | Level 2 | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Deposits with banks and short-term investments	0	0
Fair Value, Measurements, Recurring | Level 2 | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents		0
Restricted cash	0
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	0	0
Assets, fair value disclosure	975	845
Securities sold, not yet purchased	0	0
Contingent consideration liability	2,274	4,495
Derivative liabilities	0	0
Total of liabilities measured at fair value	2,274	4,495
Fair Value, Measurements, Recurring | Level 3 | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0
Fair Value, Measurements, Recurring | Level 3 | Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	685	589
Fair Value, Measurements, Recurring | Level 3 | Alternative investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring | Level 3 | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring | Level 3 | Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring | Level 3 | Private equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	290	256
Fair Value, Measurements, Recurring | Level 3 | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Deposits with banks and short-term investments	0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents		0
Restricted cash	0
Fair Value, Measurements, Recurring | NAV
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	0	0
Assets, fair value disclosure	90,768	91,676
Securities sold, not yet purchased	0	0
Contingent consideration liability	0	0
Derivative liabilities	0	0
Total of liabilities measured at fair value	0	0
Fair Value, Measurements, Recurring | NAV | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0
Fair Value, Measurements, Recurring | NAV | Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	0	0
Fair Value, Measurements, Recurring | NAV | Alternative investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	43,176	48,467
Fair Value, Measurements, Recurring | NAV | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	3	3
Fair Value, Measurements, Recurring | NAV | Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	61	50
Fair Value, Measurements, Recurring | NAV | Private equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments	47,528	43,156
Fair Value, Measurements, Recurring | NAV | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Deposits with banks and short-term investments	0	0
Fair Value, Measurements, Recurring | NAV | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and cash equivalents		$ 0
Restricted cash	$ 0