COMMITMENTS AND CONTINGENCIES - Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Lease expense	$ 1,118	$ 1,118	$ 1,046
Sublease income	(479)	(466)	(229)
Lease expense, net	639	652	817
Net cash provided by (used in) operating activities	$ (587)	$ (555)	$ (573)