Quarterly report pursuant to Section 13 or 15(d)

Net Income Per Share - Calculation (Details)

v3.23.3
Net Income Per Share - Calculation (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2023
Jun. 30, 2023
Mar. 31, 2023
Sep. 30, 2022
Jun. 30, 2022
Mar. 31, 2022
Sep. 30, 2023
Sep. 30, 2022
Net income $ 167,602 $ 164,400 $ 135,870 $ 153,746 $ 143,697 $ 114,711 $ 467,870 $ 412,156
Weighted average number of common shares outstanding - basic 31,615,110     32,076,285     31,588,740 32,404,275
Dilutive effect of common stock equivalents:                
Stock options 87,696     101,364     86,247 110,169
Weighted average number of common shares outstanding - diluted 31,788,812     32,279,820     31,744,856 32,643,161
Basic net income per common share $ 5.30     $ 4.79     $ 14.81 $ 12.72
Diluted net income per common share $ 5.27     $ 4.76     $ 14.74 $ 12.63
Service-based conditions                
Dilutive effect of common stock equivalents:                
Restricted stock awards 36,425     17,175     28,040 14,808
Market-based conditions                
Dilutive effect of common stock equivalents:                
Restricted stock awards 31,918     44,001     25,606 65,677
Performance-based conditions                
Dilutive effect of common stock equivalents:                
Restricted stock awards 17,663     40,995     16,223 48,232