ACCRUED EXPENSES AND OTHER LIABILITIES (Accrued expenses and other liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Compensation	$ 33,404	$ 47,285
Deferred revenue	3,319	3,047
Subcontractor costs	3,317	4,360
Professional fees	2,348	2,251
Business trips	2,324	939
Facilities costs	1,534	1,538
Insurance costs	1,091	810
Acquisition related deferred consideration	0	603
Deferred tax liabilities	0	365
Other	2,558	2,598
Total	$ 49,895	$ 63,796