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Share-Based Compensation and Capital Stock - Summary Of Activity Related To Restricted Stock Grants (Details) - Restricted Stock - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted shares granted 204,333 125,510 154,833
Weighted average grant date fair value (in dollars per share) $ 51.53 $ 61.41 $ 46.81
Aggregate grant date fair value $ 10,529 $ 7,707 $ 7,248
Restricted shares forfeited 28,996 19,833 23,804
Fair value of shares vested $ 7,506 $ 12,311 $ 10,280
Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting service period of shares granted 12 months 12 months 12 months
Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting service period of shares granted 48 months 48 months 48 months