INCOME TAXES - Schedule of Effective Income Tax Reconciliation (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Tax at federal statutory rate		$ 7,975	$ (36,374)	$ (22,580)
State tax, net of federal benefit		192	71	(748)
Research credit		(41)	(41)	(902)
Stock based compensation		1,259	159	1,435
Non-deductible meals and entertainment		223	973	955
Non-deductible other expense		308	6,508	1,426
Change in valuation allowance		(9,233)	1,326	44,632
Uncertain tax provisions		384	(1,611)	0
Tax rate changes	$ 25,500	0	27,560	0
Total		$ 1,067	$ (1,429)	$ 24,218