LONG-TERM LIABILITIES (Schedule of Long-Term Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts Payable and Accrued Liabilities, Noncurrent [Abstract]
Deferred rent	$ 26,904	$ 16,896
Other long-term liabilities	3,833	725
Total long-term liabilities	$ 30,737	$ 17,621