SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of significant unobservable inputs of level 3 financial assets and liabilities (Details) $ in Thousands	Sep. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value	$ 814,715	$ 873,186
Total assets measured at fair value	2,059,789	2,613,177
Mandatorily redeemable noncontrolling interests issued after November 5, 2003	4,322	4,506
Contingent consideration	29,578	0
Total liabilities measured at fair value	52,284	46,067
Significant unobservable inputs (Level 3)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value	814,715	873,186
Total assets measured at fair value	1,154,071	1,250,735
Mandatorily redeemable noncontrolling interests issued after November 5, 2003	4,322	4,506
Contingent consideration	29,578
Total liabilities measured at fair value	$ 33,900	$ 4,506
Significant unobservable inputs (Level 3) | Market interest rate
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent earnout, measurement input	0.085
Significant unobservable inputs (Level 3) | Weighted Average | Market interest rate
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent earnout, measurement input	0.085
Significant unobservable inputs (Level 3) | Market approach
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value	$ 267,745
Mandatorily redeemable noncontrolling interests issued after November 5, 2003	$ 4,322
Significant unobservable inputs (Level 3) | Market approach | Operating income multiple
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Mandatorily redeemable noncontrolling interesting, measurement input	6.0
Significant unobservable inputs (Level 3) | Market approach | Minimum | Multiple of EBITDA
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity securities, measurement input	1.80
Significant unobservable inputs (Level 3) | Market approach | Minimum | Multiple of Sales
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity securities, measurement input	1.00
Significant unobservable inputs (Level 3) | Market approach | Minimum | Market price of related security
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity securities, measurement input	10.03
Significant unobservable inputs (Level 3) | Market approach | Maximum | Multiple of EBITDA
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity securities, measurement input	13.00
Significant unobservable inputs (Level 3) | Market approach | Maximum | Market price of related security
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity securities, measurement input	16.81
Significant unobservable inputs (Level 3) | Market approach | Weighted Average | Multiple of EBITDA
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity securities, measurement input	6.49
Significant unobservable inputs (Level 3) | Market approach | Weighted Average | Multiple of Sales
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity securities, measurement input	1.00
Significant unobservable inputs (Level 3) | Market approach | Weighted Average | Market price of related security
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity securities, measurement input	13.72
Significant unobservable inputs (Level 3) | Market approach | Weighted Average | Operating income multiple
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Mandatorily redeemable noncontrolling interesting, measurement input	6.0
Significant unobservable inputs (Level 3) | Discounted cash flow
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value	$ 65,044
Fair value	814,715
Contingent consideration	$ 29,578
Significant unobservable inputs (Level 3) | Discounted cash flow | Market interest rate
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity securities, measurement input	0.178
Significant unobservable inputs (Level 3) | Discounted cash flow | EBITDA volatility
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent earnout, measurement input	0.650
Significant unobservable inputs (Level 3) | Discounted cash flow | Minimum | Market interest rate
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans receivable at fair value, measurement input	0.060
Significant unobservable inputs (Level 3) | Discounted cash flow | Maximum | Market interest rate
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans receivable at fair value, measurement input	0.335
Significant unobservable inputs (Level 3) | Discounted cash flow | Weighted Average | Market interest rate
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity securities, measurement input	0.178
Loans receivable at fair value, measurement input	0.219
Significant unobservable inputs (Level 3) | Discounted cash flow | Weighted Average | EBITDA volatility
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent earnout, measurement input	0.650
Significant unobservable inputs (Level 3) | Option pricing model
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value	$ 6,567
Significant unobservable inputs (Level 3) | Option pricing model | Minimum | Annualized volatility
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity securities, measurement input	0.300
Significant unobservable inputs (Level 3) | Option pricing model | Maximum | Annualized volatility
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity securities, measurement input	2.000
Significant unobservable inputs (Level 3) | Option pricing model | Weighted Average | Annualized volatility
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity securities, measurement input	0.574