Annual report pursuant to Section 13 and 15(d)

Stock Compensation (Summary of Stock Options Activity) (Details)

v3.20.4
Stock Compensation (Summary of Stock Options Activity) (Details) - Stock Options [Member] - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of Options, Outstanding Beginning Balance 157,830 143,415 172,409
Number of Options, Granted 18,000 34,000 16,000
Number of Options, Exercised (4,136) (15,585) (44,994)
Number of Options, Forfeited (4,000)
Number of Options, Outstanding Ending Balance 171,694 157,830 143,415
Number of Options, Exercisable at December 31, 105,094    
Weighted Average Exercise Price, Outstanding Beginning Balance $ 104.92 $ 86.42 $ 78.63
Weighted Average Exercise Price, Granted 127.22 163.95 115.45
Weighted Average Exercise Price, Exercised 62.29 62.15 66.88
Weighted Average Exercise Price, Forfeited 110.04
Weighted Average Exercise Price, Outstanding Ending Balance 108.29 $ 104.92 $ 86.42
Weighted Average Exercise Price, Exercisable at December 31, $ 89.74    
Weighted Average Remaining Contract Life, Outstanding at December 31, 4 years 5 months 26 days    
Weighted Average Remaining Contract Life, Exercisable at December 31, 3 years 10 months 6 days    
Aggregate Intrinsic Value, Outstanding at December 31, $ 5,278    
Aggregate Intrinsic Value, Exercisable at December 31, $ 4,744