INDEBTEDNESS - Facility components (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current debt, net of deferred financing costs	$ 13,243	$ 9,941
Non-current debt, net of deferred financing costs and current component	172,443	175,808
Term Loan and DDTL [Member]
Current borrowing on debt	13,691	10,412
Deferred financing costs	(448)	(471)
Current debt, net of deferred financing costs	13,243	9,941
Non-current borrowing on debt	165,755	177,069
Deferred financing costs	(812)	(1,261)
Non-current debt, net of deferred financing costs and current component	$ 164,943	$ 175,808