GOODWILL AND INTANGIBLE ASSETS - Narrative (Details) - USD ($)			3 Months Ended		9 Months Ended
	Jul. 01, 2021	Jun. 02, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Acquired Finite-Lived Intangible Assets [Line Items]
Acquisition and merger-related expense		$ 4,900,000
Goodwill impairment					$ 0	$ 0
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			$ 32,800,000	$ 11,100,000	$ 60,700,000	$ 13,700,000
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