XML 152 R115.htm IDEA: XBRL DOCUMENT v3.21.1
Share-Based Compensation And Share Repurchase Plans (Summary Of Stock Options Outstanding And Exercisable) (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Weighted Average Exercise Price of Options Outstanding, Granted $ 4.66 $ 16.12 $ 16.40  
Weighted Average Remaining Years of Contractual Life 2 years 2 months 4 days 2 years 9 months 14 days 2 years 10 months 17 days 3 years 1 month 24 days
Aggregate Intrinsic Value, Beginning balance $ 136,350 $ 1,530,528 $ 3,054,325  
Aggregate Intrinsic Value, Exercised   185,175 610,249  
Aggregate Intrinsic Value, Ending balance $ 13,969 $ 136,350 $ 1,530,528 $ 3,054,325
Class A [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of Stock Options, Beginning balance 711,377 586,469 524,589  
Number of Stock Options, Granted 38,803 219,408 126,840  
Number of Stock Options, Exercised   (69,500) (60,000)  
Number of Stock Options, Expired (36,701) (25,000) (4,960)  
Number of Stock Options Outstanding, Ending balance 713,479 711,377 586,469 524,589
Weighted Average Exercise Price of Options Outstanding, Beginning price $ 14.74 $ 14.01 $ 12.50  
Weighted Average Exercise Price of Options Outstanding, Granted 4.66 16.12 16.40  
Weighted Average Exercise Price of Options Outstanding, Exercised   13.42 6.02  
Weighted Average Exercise Price of Options Outstanding, Expired 14.74 13.42 12.08  
Weighted Average Exercise Price of Options Outstanding, Ending price $ 14.64 $ 14.74 $ 14.01 $ 12.50