INDEBTEDNESS - Credit facility (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current debt, net of deferred financing costs	$ 11,872	$ 9,941
Non-current debt, net of deferred financing costs and current component	188,094	175,808
Long Term Debt Current [Member]
Borrowing on secured term loan	12,338	10,412
Deferred financing costs	(466)	(471)
Current debt, net of deferred financing costs	11,872	9,941
Long Term Debt Noncurrent [Member]
Borrowing on secured term loan	174,240	177,069
Deferred financing costs	(1,146)	(1,261)
Non-current debt, net of deferred financing costs and current component	$ 173,094	$ 175,808