v3.21.2
STOCKHOLDERS' EQUITY - Restricted Stock (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized          
Stock-based compensation     $ 4,170 $ 4,712  
Restricted stock          
Restricted Stock          
Outstanding at period start (in shares)     436,730    
Granted (in shares)     111,637    
Forfeited (in shares)     (4,188)    
Vested (in shares)     (168,264)    
Outstanding at period end (in shares) 375,915   375,915   436,730
Weighted-average remaining contractual terms (in years)     1 year 4 months 24 days   1 year 1 month 6 days
Restricted stock exercisable (in shares) 0   0    
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized          
Vesting period (in years)     3 years    
Unrecognized compensation expense $ 8,694   $ 8,694    
Unrecognized compensation expense, weighted average period of recognition (in years)     1 year 4 months 24 days    
Stock-based compensation $ 1,440 $ 1,259 $ 4,170 $ 4,712