STOCK-BASED COMPENSATION - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 794	$ 93	$ 1,096	$ 237
Restricted common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	92	0	182	0
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 702	$ 93	$ 914	$ 237