STOCK-BASED COMPENSATION - SUMMARY OF TIME-BASED STOCK OPTIONS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Number of Shares Underlying Stock Options
Ending outstanding balance (in shares)	521,000
Weighted Average Exercise Price Per Share
Weighted average remaining contractual life, Outstanding	5 years 2 months 15 days	4 years 4 months 9 days
Time-based stock options
Number of Shares Underlying Stock Options
Beginning outstanding balance (in shares)	828,000
Granted (in shares)	0
Exercised (in shares)	(307,000)
Canceled or expired (in shares)	0
Ending outstanding balance (in shares)	521,000	828,000
Number of shares underlying stock options, Vested and expected to vest (in shares)	447,000
Number of shares underlying stock options, Exercisable (in shares)	129,000
Weighted Average Exercise Price Per Share
Beginning outstanding balance (in dollars per share)	$ 8.16
Granted (in dollars per share)	0
Exercised (in dollars per share)	8.87
Canceled or expired (in dollars per share)	0
Ending outstanding balance (in dollars per share)	7.74	$ 8.16
Weighted average exercise price, Vested and expected to vest (in dollars per share)	7.76
Weighted average exercise price, Exercisable (in dollars per share)	$ 8.32
Weighted average remaining contractual life, Vested and expected to vest	5 years 2 months 4 days
Weighted average remaining contractual life, Exercisable	4 years 8 months 8 days
Aggregate intrinsic value, Outstanding	$ 1,020	$ 2,628
Aggregate intrinsic value, Vested and expected to vest	866
Aggregate intrinsic value, Exercisable	$ 212