REVENUE RECOGNITION AND RELATED ALLOWANCES - Timing (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Revenue recognition	$ 52,061		$ 52,979	$ 155,207	$ 151,223
Performance obligations satisfied in prior periods				11,000	(8,700)
Deferred revenue	62			62		$ 80
Revenue recognized			100		300
Performance obligations transferred at a point in time [Member]
Revenue recognition	51,984		52,690	154,875	149,472
Performance obligations transferred over time [Member]
Revenue recognition	77		$ 289	332	$ 1,751
Maximum
Revenue recognized	$ 100			100
Tripartite Agreement-Yescart
Revenue recognition		$ 11,200		$ 11,200