GOODWILL AND INTANGIBLE ASSETS - Narrative (Details) - USD ($)			3 Months Ended		12 Months Ended
	Jul. 01, 2021	Jun. 02, 2021	Sep. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Acquisition and merger-related expense		$ 5,100,000
Goodwill, acquired during period					$ 417,753,000	$ 224,601,000
Goodwill impairment					0	0
Strategic Initiatives
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill, acquired during period			$ 224,600,000		0	224,601,000
Management contracts
Acquired Finite-Lived Intangible Assets [Line Items]
Fully-amortized intangibles, amount removed during the period					3,400,000
General, administrative and other expense
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expense					$ 91,300,000	$ 24,500,000	$ 3,400,000
Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful lives, intangible assets					8 years 4 months 24 days
Black Creek Acquisition | Management contracts
Acquired Finite-Lived Intangible Assets [Line Items]
Acquisition and merger-related expense	$ 576,200,000
Acquired finite lived intangible assets useful life	6 years 1 month 6 days
Black Creek Acquisition | Client relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Acquisition and merger-related expense	$ 7,200,000
Acquired finite lived intangible assets useful life	12 years
SSG Acquisition | Management contracts
Acquired Finite-Lived Intangible Assets [Line Items]
Acquisition and merger-related expense			$ 171,700,000
Estimated useful lives, intangible assets			5 years 9 months 18 days
SSG Acquisition | Client relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Acquisition and merger-related expense			$ 18,800,000
Estimated useful lives, intangible assets			10 years
SSG Acquisition | Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Acquisition and merger-related expense			$ 10,700,000
Estimated useful lives, intangible assets			10 years
Crestline Denali
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful lives, intangible assets				6 years 7 months 6 days
Finite-lived intangible assets acquired				$ 34,700,000
Energy Investors Funds
Acquired Finite-Lived Intangible Assets [Line Items]
Non- cash impairment charge							20,000,000
Energy Investors Funds | Client Relationships and Trade Names
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets removed							$ 35,100,000