Earnings Per Share (Schedule Of Computation Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share [Abstract]
Earnings	$ 272,509	$ 249,624	$ 268,550
Diluted earnings	$ 272,509	$ 249,624	$ 268,550
Earnings, Shares	15,050	14,929	15,671
Dilutive stock options, Shares	103	130	221
Nonvested stock awards, Shares	47	40	46
Diluted earnings, Shares	15,200	15,099	15,938
Earnings, Earnings per Share	$ 18.11	$ 16.72	$ 17.14
Diluted earnings, Earnings per Share	$ 17.93	$ 16.53	$ 16.85