Annual report pursuant to Section 13 and 15(d)

Stock Incentive Plan - Narrative (Details)

v3.22.0.1
Stock Incentive Plan - Narrative (Details)
12 Months Ended
Dec. 31, 2021
USD ($)
contribution
$ / shares
shares
Dec. 31, 2020
USD ($)
$ / shares
Dec. 31, 2019
USD ($)
$ / shares
May 31, 2016
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of shares authorized under the plan (in shares) | shares       2,000,000
Shares available for grant (in shares) | shares 801,000      
Expected life of options (in years) 7 years      
Share-based awards, vesting period 3 years      
Weighted average remaining contractual term for options outstanding 3 years      
Fair value of stock options vested $ 922,000 $ 1,377,000 $ 1,887,000  
Continuing Operations        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Average aggregate intrinsic value for options outstanding 21,459,000      
Average aggregate instrinsic value for exercisable options 17,677,000      
Aggregate intrinsic value of options exercised 2,137,000 1,568,000 2,196,000  
Discontinued Operations        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Fair value of stock options vested 58,000 56,000 0  
Aggregate intrinsic value of options exercised $ 458,000 193,000 0  
Performance Shares        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based awards, vesting period 3 years      
Measurement period 3 years      
Minimum percentage of shares attainable 0.00%      
Maximum percentage of shares attainable 200.00%      
Performance Shares | Continuing Operations        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized compensation cost $ 3,618,000      
Cost not yet recognized, period for recognition 2 years      
Weighted-average fair value of each purchase (in dollars per share) | $ / shares $ 87.33      
Excess tax benefit related to exercise of stock options $ 911,000 2,340,000 2,621,000  
Performance Shares | Discontinued Operations        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Excess tax benefit related to exercise of stock options $ 95,000 $ 75,000 $ 95,000  
Employee Stock Purchase Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of shares authorized under the plan (in shares) | shares 323,000      
Percentage of share price for shares issued 90.00%      
Purchase period 6 months      
Number of lump sum contributions | contribution 2      
Employee Stock Purchase Plan | Continuing Operations        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Weighted-average fair value of each purchase (in dollars per share) | $ / shares $ 30.68 $ 20.99 $ 13.68  
Employee Stock Purchase Plan | Discontinued Operations        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Weighted-average fair value of each purchase (in dollars per share) | $ / shares $ 0 $ 18.11 $ 13.48  
Non-employee Director Stock Options | Continuing Operations        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of shares authorized under the plan (in shares) | shares 360,000      
Shares available for grant (in shares) | shares 75,000      
Employee Stock Option        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based awards, vesting period 3 years      
Unrecognized compensation cost $ 695,000      
Cost not yet recognized, period for recognition 2 years      
Director Restricted Shares | Continuing Operations        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized compensation cost $ 527,000      
Cost not yet recognized, period for recognition 1 year      
Weighted-average fair value of each purchase (in dollars per share) | $ / shares $ 93.39      
Grant date fair value of shares that vested during the year $ 2,514,000 $ 771,000 $ 970,000  
Employee Non-vested Shares | Continuing Operations        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized compensation cost $ 7,794,000      
Cost not yet recognized, period for recognition 2 years      
Weighted-average fair value of each purchase (in dollars per share) | $ / shares   $ 65.88 $ 59.49  
Grant date fair value of shares that vested during the year $ 8,487,000 $ 9,180,000 $ 7,684,000  
Employee Non-vested Shares | Discontinued Operations        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Weighted-average fair value of each purchase (in dollars per share) | $ / shares   $ 63.24 $ 59.07  
Grant date fair value of shares that vested during the year $ 364,000 $ 625,000 $ 270,000  
Restricted Stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based awards, vesting period 3 years      
Restricted Stock | Share-based Payment Arrangement, Tranche One        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based awards, vesting period 1 year      
Restricted Stock | Continuing Operations        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Weighted-average fair value of each purchase (in dollars per share) | $ / shares $ 75.35      
Restricted Stock | Discontinued Operations        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Weighted-average fair value of each purchase (in dollars per share) | $ / shares $ 0