STOCK BASED COMPENSATION - RSUs (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Stock-based compensation
Stock-based compensation expense	$ 2,856	$ 2,645	$ 7,164	$ 8,328
Restricted Stock Units (RSUs)
Stock-based compensation
Stock-based compensation expense	400	500	900	1,300
Unamortized stock-based compensation costs for unvested awards	$ 3,900	$ 5,100	$ 3,900	$ 5,100
Summary of restricted stock units outstanding
Outstanding at beginning of period ( in shares)			469,485
Awarded (in shares)			305,600
Released (in shares)			(45,840)
Forfeited (in shares)			(196,131)
Outstanding at end of period ( in shares)	533,114		533,114
Nonvested at end of period (in shares)	528,712		528,712
Weighted-Average Grant Date Fair Value
Outstanding at beginning of period (in dollars per share)			$ 18.05
Awarded (in dollars per share)			3.78
Released (in dollars per share)			25.57
Forfeited (in dollars per share)			18.36
Outstanding at end of period (in dollars per share)	$ 9.10		9.10
Nonvested at end of period (in dollars per share)	$ 9.06		$ 9.06
Aggregate Intrinsic Value
Outstanding at end of period (in dollars)	$ 496		$ 496		$ 4,202
Nonvested at end of period (in dollars)	$ 492		$ 492
Weighted Average Remaining Recognition Period (in years)			3 years 1 month 6 days	2 years 10 months 24 days