Earnings per Share Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Net Income (Loss) Attributable to Parent	$ 139,016	$ 131,590	$ 360,083	$ 360,267
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Weighted Average Number of Shares Outstanding, Basic	27,909	27,618	27,769	28,025
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Incremental Common Shares Attributable to Stock Options	638	248	552	274
Deferred Compensation Awards	290	319	310	311
Diluted Weighted Average Number of Shares Outstanding	28,837	28,185	28,631	28,610
Earnings Per Share, Basic	$ 4.98	$ 4.76	$ 12.97	$ 12.86
Earnings Per Share, Diluted	$ 4.82	$ 4.67	$ 12.58	$ 12.59
Anti-dilutive stock equivalent awards not included in the calculation of diluted loss per share	0	908	0	826