SHARE-BASED COMPENSATION - Equity Compensation Plan and RSU Acitivity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restricted Stock Unit Activity [Abstract]
RSUs issued	808,443	1,123,000	796,000
RSUs forfeited	(379,190)	(27,000)	(58,000)
Net RSUs issued and increase (decrease) to paid-in capital	2,685,000	1,096,000	738,000
RSUs vested and released	474,069	611,000	406,000
RSUs issued, Amount	$ 35,628	$ 10,381	$ 9,045
Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures To Paid In Capital	$ 34,511	$ 10,101	$ 8,336
Equity Compensation Plan [Abstract]
Additional shares available for grant during the next period	1,500,000
Shares available for grant	2,600,000