Earnings Per Share (Schedule Of Computation Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings Per Share [Abstract]
Earnings	$ 56,873	$ 72,003	$ 187,498	$ 193,925
Diluted earnings	$ 56,873	$ 72,003	$ 187,498	$ 193,925
Earnings, Shares	14,888	15,587	14,935	15,808
Dilutive stock options, Shares	118	215	140	233
Nonvested stock awards, Shares	36	40	39	42
Diluted earnings, Shares	15,042	15,842	15,114	16,083
Earnings, Earnings per Share	$ 3.82	$ 4.62	$ 12.55	$ 12.27
Diluted earnings, Earnings per Share	$ 3.78	$ 4.55	$ 12.41	$ 12.06