STOCKHOLDERS' EQUITY - Stock option activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
STOCKHOLDERS' EQUITY
Options outstanding at beginning of period, Number of options	1,878,168
Options granted, Number of options	719,050
Options expired, Number of options	(78,692)
Options forfeited, Number of options	(209,098)
Options outstanding at end of period, Number of options	2,309,428	1,878,168
Options vested and expected to vest at end of period, Number of options	2,149,618
Exercisable at end of period, Number of options	842,507
Options outstanding at beginning of period, Weighted average exercise price	$ 18.13
Options granted, Weighted average exercise price	7.14
Options expired, Weighted average exercise price	17.47
Options forfeited, Weighted average exercise price	13.91
Options outstanding at end of period, Weighted average exercise price	15.12	$ 18.13
Options vested and expected to vest at end of period, Weighted average exercise price	15.23
Exercisable at end of period, Weighted average exercise price	$ 20.07
Options outstanding at, Weighted Average remaining contractual life	7 years 4 months 20 days	6 years 11 months 15 days
Options vested and expected to vest at end of period, Weighted Average remaining contractual life	7 years 4 months 6 days
Exercisable at end of year, Weighted Average remaining contractual life	5 years 6 months 14 days
Options outstanding at beginning of period, Aggregate Intrinsic value	$ 3,861
Options outstanding at end of period, Aggregate Intrinsic value	253	$ 3,861
Options vested and expected to vest at end of period, Aggregate Intrinsic value	245
Exercisable at end of period, Aggregate Intrinsic value	$ 206