INCOME TAXES - Unrecognized tax benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 731	$ 731
Additions for current year tax positions	27	0
Additions included in purchase accounting for prior year positions	129	0
Reductions for prior year tax positions	0	0
Ending Balance (excluding interest and penalties)	887	731
Interest and penalties	0	0
Total	$ 887	$ 731