INCOME TAXES - Schedule of Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating losses	$ 5,885	$ 6,618
Tax credit carryforwards	1,411	1,096
Intangibles	82,582	33,604
Stock-based compensation	1,907	2,286
Operating lease liabilities	1,577
Reserves and other accruals not currently deductible	10,447	10,706
Total deferred tax assets	103,809	54,310
Valuation allowance for deferred tax assets	(90,820)	(41,905)
Deferred tax assets	12,989	12,405
Deferred tax liabilities:
Convertible debt	(12,247)	(12,213)
Fixed Assets	(109)	(192)
Operating lease right-of-use assets	(633)
Net deferred tax asset (liability)	$ 0	$ 0