Earnings per Share - Calculation (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net earnings	$ 1,123,818	$ 683,451	$ 677,918
Basic earnings per common share:
Net earnings (in dollars per basic share)	$ 7.81	$ 4.74	$ 4.67
Weighted average basic shares outstanding (in shares)	143,923,000	144,050,000	145,198,000
Diluted earnings per common share:
Net earnings (in dollars per diluted share)	$ 7.74	$ 4.70	$ 4.61
Weighted average diluted shares outstanding (in shares)	145,273,000	145,393,000	146,992,000