INCOME TAXES - Schedule of Tax Effects of Temporary Differences and Net Operating Losses ("NOL") (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Operating loss carryforwards	$ 37,860	$ 36,150
Other accrued expenses	4,248	2,833
Outside basis difference in ASV	13,891	13,367
Tax credit carryforwards	1,714	1,859
Original issue discount	1,806
Other	4,562	3,504
Total deferred tax asset	64,081	57,713
Valuation allowance	(59,011)	(51,850)
Total deferred tax asset, net	5,070	5,863
Deferred tax liabilities:
Property and equipment	(299)	(2,193)
Intangible assets	(1,041)	(1,116)
Deferred revenue	(3,730)	(394)
Total deferred tax liabilities	$ (5,070)	(3,703)
Net deferred tax asset		$ 2,160