COST OF REVENUE (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Cost of Revenue [Abstract]
Compensation and benefits	$ 60,332	$ 66,357	$ 186,090	$ 201,193
Outside fees and services	83,670	77,445	250,883	222,574
Cost of real estate sold	4,411	0	16,461	0
Reimbursable expenses	9,866	12,080	31,786	41,317
Technology and telecommunications	10,389	11,502	32,681	32,145
Depreciation and amortization	6,230	6,618	20,343	20,007
Cost of revenue	$ 174,898	$ 174,002	$ 538,244	$ 517,236