COMMITMENTS AND CONTINGENCIES - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
COMMITMENTS AND CONTINGENCIES
Unfunded capital commitments	$ 720,800,000	$ 677,300,000
Maximum exposure from guarantees	17,300,000	209,700,000
Performance Income
Carried interest, contingent repayment obligations	0	0
Performance income
Performance Income
Performance income subject to potential clawback provision	185,500,000	194,600,000
Performance income subject to potential claw back provision that are reimbursable by professionals	146,300,000	153,300,000
Landmark Acquisition
COMMITMENTS AND CONTINGENCIES
Commitment, maximum amount	$ 300,000,000
Business combination, percentage	15.00%
Business combination equity awards percentage	85.00%
Vesting period	4 years
Estimated fair value of the contingent consideration liability	$ 145,700,000	145,700,000
Compensation expense	8,900,000
Accrued compensation	29,900,000	21,000,000
Black Creek Acquisition
COMMITMENTS AND CONTINGENCIES
Commitment, maximum amount	275,000,000
Compensation expense	37,700,000
Fair value of contingent liability	253,200,000	229,500,000
Accrued compensation	83,600,000	$ 45,900,000
Infrastructure Debt Acquisition
COMMITMENTS AND CONTINGENCIES
Commitment, maximum amount	$ 48,500,000
Business combination, percentage	15.00%
Business combination equity awards percentage	85.00%
Estimated fair value of the contingent consideration liability	$ 39,800,000
Compensation expense	$ 1,400,000
Recognition period	4 years