GOODWILL AND INTANGIBLE ASSETS (Carrying Value of Intangible Assets) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Feb. 21, 2020 contract	Dec. 31, 2019 USD ($)
Finite-lived intangible assets, net
Intangible assets	$ 49,266			$ 19,217
Less: accumulated amortization	(7,592)			(11,242)
Intangible assets, net	41,674			7,975
Number of collateral management contracts acquired | contract			7
Fully-amortized intangibles, amount removed during the period	$ 4,700
Crestline Denali
Finite-lived intangible assets, net
Estimated useful lives, intangible assets	6 years 6 months
Finite-lived intangible assets acquired	$ 34,700
General, administrative and other expense
Finite-lived intangible assets, net
Amortization expense	$ 1,000	$ 1,200
Management contracts
Finite-lived intangible assets, net
Estimated useful lives, intangible assets	6 years 3 months 18 days
Intangible assets	$ 42,547			12,498
Client relationships
Finite-lived intangible assets, net
Estimated useful lives, intangible assets	8 years 3 months 18 days
Intangible assets	$ 6,341			6,341
Trade name
Finite-lived intangible assets, net
Estimated useful lives, intangible assets	2 years 3 months 18 days
Intangible assets	$ 378			$ 378