Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation (Summary of Restricted Stock Unit Activity) (Details)

v3.19.3.a.u2
Stock-Based Compensation (Summary of Restricted Stock Unit Activity) (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Restricted stock units outstanding, beginning, number of shares 424,001 449,475 466,475
Granted, number of shares 177,618 197,299 270,169
Vested, number of shares (163,195) (155,847) (176,654)
Forfeited, number of shares (33,320) (66,926) (110,515)
Restricted stock units outstanding, ending, number of shares 405,104 424,001 449,475
Restricted stock units outstanding, beginning, weighted average grate date fair value per share $ 62.38 $ 52.07 $ 47.23
Granted, weighted average grant date fair value per share 94.58 73.74 52.45
Vested, weighted average grant date fair value 60.45 50.97 42.32
Forfeited, weighted average grant date fair value 72.35 53.19 48.13
Restricted stock units outstanding, ending, weighted average grate date fair value per share $ 76.45 $ 62.38 $ 52.07