Quarterly report pursuant to Section 13 or 15(d)

Stock compensation (Details)

v3.22.1
Stock compensation (Details)
$ in Thousands
3 Months Ended
Mar. 23, 2022
USD ($)
shares
Mar. 31, 2022
USD ($)
installment
shares
Mar. 31, 2021
USD ($)
shares
Dec. 31, 2021
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options forfeited (in shares)   0    
Options granted (in shares)   0    
Options exercised (in shares)   27,403    
Options outstanding (in shares)   132,167   159,570
Tax withholdings for share based payment arrangement | $   $ 931 $ 3,197  
Stock Options        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expiration period (in years)   10 years    
Compensation expense | $   $ 100 200  
Restricted Stock Units (RSUs)        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock units forfeited (in shares)   55,396    
Compensation expense | $   $ 500 $ 1,400  
Number of annual vesting installments | installment   5    
Stock units granted (in shares)   38,151    
Stock units vested (in shares)   16,076    
Tax withholdings for share based payment arrangement (in shares)   5,843 20,791  
Issuance of common stock in connection with share-based compensation (in shares)   10,233 28,392  
Awards outstanding (in shares)   85,270   118,591
Restricted Stock Units (RSUs) | Minimum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Possible target award adjustment based on strategic and operational accomplishments   75.00%    
Restricted Stock Units (RSUs) | Maximum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Possible target award adjustment based on strategic and operational accomplishments   125.00%    
Restricted Stock Units (RSUs) | Chief Executive Officer        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Payment for forfeited shares | $ $ 6,600      
Stock units forfeited (in shares) 41,186      
Restricted Stock Units (RSUs) | Director        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Issuance of common stock in connection with share-based compensation (in shares)   0 0  
Restricted Stock Units (RSUs) | RSU Granted Prior to 2016        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period (in years)   6 years    
Restricted Stock Units (RSUs) | RSU Granted Prior to 2016 | Vesting period 1        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting percentage (as a percent)   20.00%    
Restricted Stock Units (RSUs) | RSU Granted Prior to 2016 | Vesting period 2        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting percentage (as a percent)   20.00%    
Restricted Stock Units (RSUs) | RSUs Granted During and Subsequent to 2016 | Vesting period 1        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period (in years)   5 years    
Vesting percentage (as a percent)   20.00%    
Restricted Stock Units (RSUs) | RSUs Granted During and Subsequent to 2016 | Vesting period 2        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period (in years)   3 years    
Restricted Stock Units (RSUs) | Retirement Plan for Non-Employee Directors | Director        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Compensation expense | $   $ 300 $ 200  
Issuance of common stock in connection with share-based compensation (in shares)   1,000    
Restricted Stock Units (RSUs) | Retirement Plan for Non-Employee Directors | Director | Maximum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Issuance of common stock in connection with share-based compensation (in shares)   10,000