Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Reconciliation of information used in computing basic and diluted earnings per share [Abstract]
Net earnings	$ 281,822	$ 242,239	$ 914,043	$ 470,813
Basic earnings per common share:
Net earnings (in dollars per share)	$ 2.05	$ 1.73	$ 6.61	$ 3.37
Weighted average shares outstanding (in shares)	137,443	139,862	138,247	139,810
Diluted earnings per common share:
Net earnings (in dollars per share)	$ 2.04	$ 1.72	$ 6.57	$ 3.35
Weighted average shares outstanding (in shares)	138,404	140,578	139,136	140,597
Reconciliation Of Share Amounts Used In Computing Earnings Per Share [Abstract]
Weighted average shares outstanding - basic (in shares)	137,443	139,862	138,247	139,810
Dilutive effect of assumed exercise of SARs and vesting of performance shares and RSUs (in shares)	961	716	889	787
Weighted average shares outstanding - Diluted (in shares)	138,404	140,578	139,136	140,597
Antidilutive securities excluded from computation of earnings per share	37	34	72	61