DEFERRED REVENUE AND COSTS (DEFERRED REVENUE CLASSIFICATION TABLE) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
DEFERRED REVENUE AND COSTS [ABSTRACT]
Deferred revenue - current	$ 44,926	$ 46,435	$ 21,650
Deferred revenue - long-term	33,247		9,632
Total deferred revenue	$ 78,173		$ 31,282