INCOME TAXES - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating losses	$ 8,004	$ 24,330
Research and development credit carryforwards	3,104	5,147
Minimum tax credit carryforwards	31	123
Disallowed interest expense carryforwards	0	1,909
Stock compensation	168	107
Deferred revenue	588	276
Fixed assets	0	14
Accrued expenses	349	359
Lease liabilities	1,905
Goodwill	2,132	0
Other	347	525
Gross current deferred tax assets	16,628	32,790
Valuation allowance	(5,204)	(20,053)
Net deferred tax assets	11,424	12,737
Deferred tax liabilities:
Acquired intangibles	(7,828)	(10,460)
Fixed assets	(125)	0
Capitalized software	(1,353)	(1,001)
Deferred commission	(698)	(496)
Right-of-use asset	(1,756)
Goodwill	0	(1,649)
Gross noncurrent deferred tax assets	(11,760)	(13,606)
Net deferred liabilities	$ (336)	$ (869)