Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation Plans - Narrative (Details)

v3.20.4
Stock-Based Compensation Plans - Narrative (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Mar. 02, 2019
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
May 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Shares available for issuance (in shares)   725,945      
Tax withholding associated with awards issued   $ 690 $ 955 $ 641  
Compensation expense not yet recognized   $ 873      
Weighted average amortization period of compensation not yet recognized   1 year 7 months 6 days      
Restricted Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Tax withholding associated with awards issued   $ 690 688 641  
Stock-based compensation expense   2,858 3,264 2,885  
Restricted Stock | Non-employee Directors          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock-based compensation expense   635 597 553  
Restricted Stock | Employee          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock-based compensation expense   $ 2,223 $ 2,667 $ 2,332  
Restricted Stock Plan 2006          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Shares authorized (in shares)   1,500,000     500,000
Restricted Stock Plan 2006 | Non-employee Directors          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Restricted stock awarded (in shares)   16,100 18,900 11,200  
Stock-based compensation expense   $ 605 $ 597 $ 553  
Restricted Stock Plan 2006 | Employee          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Restricted stock awarded (in shares) 42,946        
Grant date fair value (in dollars per share) $ 28.67        
Vested award is paid in our shares 100.00%        
Restricted Stock Plan 2006 | Restricted Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Grant date fair value (in dollars per share)   $ 32.23 $ 32.56 $ 0  
Restricted Stock Plan 2006 | Restricted Stock | Non-employee Directors          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Grant date fair value (in dollars per share)   $ 37.55 $ 31.58 $ 49.38