OTHER CURRENT ASSETS AND LONG-TERM ASSETS (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid expenses	$ 3,085	$ 1,879
Deposits and other receivables	1,600	759
Interest receivables	237	183
Other current assets	4,922	2,821
Other Assets, Noncurrent [Abstract]
Deposits paid for research and development	$ 1,000	$ 3,300