ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Salaries, commissions and benefits	$ 29,547	$ 21,843
Sales, use, transaction and income taxes	8,872	7,438
Fees for professional services	1,601	1,148
Rent	1,716	1,920
Deferred revenue	1,231	1,024
Other accruals	2,598	2,781
Total accrued expenses and other current liabilities	$ 45,565	$ 36,154