FAIR VALUE MEASUREMENTS - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	$ 690,199		$ 690,199		$ 683,496
Assets, fair value disclosure					698,050
Securities sold, not yet purchased	$ 1,550		$ 1,550		$ 4,651
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other	Other	Other	Other
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other assets		Other assets		Other assets
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	$ 715		$ 715		$ 14,554
Assets, fair value disclosure	690,914		690,914
Securities sold, not yet purchased	1,550		1,550		4,651
Contingent consideration liability	6,422		6,422
Derivative liabilities	378,300		378,300		327,160
Total of liabilities measured at fair value	386,272		386,272		331,811
Fair Value, Measurements, Recurring | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	5,022		5,022
Fair Value, Measurements, Recurring | Equities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	44,603		44,603		43,889
Fair Value, Measurements, Recurring | Alternative investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	59,817		59,817		56,947
Fair Value, Measurements, Recurring | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	183,352		183,352		178,556
Fair Value, Measurements, Recurring | Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	354,223		354,223		350,282
Fair Value, Measurements, Recurring | Private equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	43,182		43,182		53,822
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, fair value disclosure	602,278		602,278		599,110
Securities sold, not yet purchased	1,550		1,550		4,651
Derivative liabilities					115
Total of liabilities measured at fair value	1,550		1,550		4,766
Fair Value, Measurements, Recurring | Level 1 | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	5,022		5,022
Fair Value, Measurements, Recurring | Level 1 | Equities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	43,961		43,961		43,243
Fair Value, Measurements, Recurring | Level 1 | Alternative investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	15,767		15,767		27,073
Fair Value, Measurements, Recurring | Level 1 | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	183,348		183,348		178,552
Fair Value, Measurements, Recurring | Level 1 | Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	354,180		354,180		350,242
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	715		715		14,554
Assets, fair value disclosure	715		715		14,554
Derivative liabilities	378,300		378,300		327,045
Total of liabilities measured at fair value	378,300		378,300		327,045
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, fair value disclosure	910		910		19,418
Contingent consideration liability	6,422		6,422
Total of liabilities measured at fair value	6,422		6,422
Fair Value, Measurements, Recurring | Level 3 | Equities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	642		642		646
Fair Value, Measurements, Recurring | Level 3 | Private equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	268		268		18,772
Fair Value, Measurements, Recurring | NAV
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets, fair value disclosure	87,011		87,011		64,968
Fair Value, Measurements, Recurring | NAV | Alternative investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	44,050		44,050		29,874
Fair Value, Measurements, Recurring | NAV | Debt
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	4		4		4
Fair Value, Measurements, Recurring | NAV | Equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	43		43		40
Fair Value, Measurements, Recurring | NAV | Private equity
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, at fair value	$ 42,914		$ 42,914		$ 35,050