PREPAID EXPENSES AND OTHER CURRENT ASSETS - Schedule of Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid expenses	$ 3,419	$ 2,666
Other	4,423	3,481
Total	7,842	6,147
Property and equipment, gross	$ 64,631	$ 60,924