Earnings Per Common Share (Summary Of Computation Of Basic And Diluted Earnings Per Common Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings Per Share [Abstract]
Income available to common shareholders	$ 42,068	$ 35,434	$ 115,267	$ 117,397
Denominator for basic earnings per share (weighted average common shares outstanding)	16,253,704	16,292,312	16,240,966	16,315,996
Effect of dilutive options and warrants	121,278	131,600	114,824	129,572
Denominator for diluted earnings per share (weighted average common shares outstanding adjusted for the effect of dilutive options and warrants)	16,374,982	16,423,912	16,355,790	16,445,568
Basic earnings per common share	$ 2.59	$ 2.17	$ 7.10	$ 7.20
Diluted earnings per common share	$ 2.57	$ 2.16	$ 7.05	$ 7.14