COST OF REVENUE (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Cost of Revenue [Abstract]
Compensation and benefits	$ 24,913	$ 36,806	$ 50,829	$ 78,174
Outside fees and services	41,761	58,588	89,901	121,169
Technology and telecommunications	9,074	9,060	18,306	18,538
Reimbursable expenses	3,840	4,775	11,685	9,271
Depreciation and amortization	3,040	3,209	6,488	7,407
Cost of real estate sold	0	40,276	0	42,370
Total	$ 82,628	$ 152,714	$ 177,209	$ 276,929