GOODWILL AND INTANGIBLE ASSETS (Carrying Value of Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Finite-lived intangible assets, net
Total intangible assets	$ 84,135		$ 109,106
Less: accumulated amortization	(46,957)		(68,641)
Intangible assets, net	37,178		40,465
Fully-amortized intangibles, amount removed during the period	25,000
General, administrative and other expense
Finite-lived intangible assets, net
Amortization expense	$ 3,300	$ 5,300
Management contracts
Finite-lived intangible assets, net
Weighted average amortization period	2 years 2 months 12 days
Intangible assets	$ 42,335		67,306
Client relationships
Finite-lived intangible assets, net
Weighted average amortization period	10 years 3 months 18 days
Intangible assets	$ 38,600		38,600
Trade name
Finite-lived intangible assets, net
Weighted average amortization period	4 years 3 months 18 days
Intangible assets	$ 3,200		$ 3,200