GOODWILL AND INTANGIBLE ASSETS (Carrying Value of Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-lived intangible assets, net
Intangible assets, gross	$ 153,739	$ 205,269
Foreign currency translation	(3,205)	(1,436)
Total intangible assets acquired	150,534	203,833
Less: accumulated amortization	(92,219)	(118,862)
Intangible assets, net	58,315	84,971
Fully-amortized intangibles, amount removed during the period	51,500
General, administrative and other expense
Finite-lived intangible assets, net
Amortization expense	$ 26,600	46,200	$ 27,600
Management contracts
Finite-lived intangible assets, net
Weighted average amortization period	2 years
Intangible assets, gross	$ 111,939	163,469
Client relationships
Finite-lived intangible assets, net
Weighted average amortization period	11 years 6 months
Intangible assets, gross	$ 38,600	38,600
Trade Name
Finite-lived intangible assets, net
Weighted average amortization period	5 years 6 months
Intangible assets, gross	$ 3,200	$ 3,200