Annual report pursuant to Section 13 and 15(d)

Net Income Per Share - Calculation (Details)

v3.22.0.1
Net Income Per Share - Calculation (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Net income - basic and diluted $ 324,016 $ 247,023 $ 190,995
Weighted average number of common shares outstanding - basic 32,801,906 32,917,971 33,806,104
Dilutive effect of common stock equivalents:      
Stock options 130,150 138,354 225,049
Weighted average number of common shares outstanding - diluted 33,146,171 33,299,986 34,376,555
Basic net income per common share $ 9.88 $ 7.50 $ 5.65
Diluted net income per common share $ 9.78 $ 7.42 $ 5.56
Service-based conditions      
Dilutive effect of common stock equivalents:      
Restricted stock awards 21,130 51,324 87,159
Market-based conditions      
Dilutive effect of common stock equivalents:      
Restricted stock awards 127,723 150,530 189,044
Performance-based conditions      
Dilutive effect of common stock equivalents:      
Restricted stock awards 65,262 41,807 69,199