ACCRUED LIABILITIES (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
ACCRUED LIABILITIES
Compensation and fringe benefits	$ 8,255	$ 14,666
Accrued business acquisition consideration	12,416	12,388
Warranty reserve	1,946	1,869
Income taxes payable	1,015	970
Operating lease liabilities - current	$ 3,759	4,532
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued liabilities		Accrued liabilities
Finance Lease, Liability, Current	$ 318
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued liabilities		Accrued liabilities
Deferred revenue	$ 7,647	2,425
Other accrued expenses	4,619	4,806
Accrued liabilities	$ 39,975	$ 41,656