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, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Income available to common shareholders	$ 36,917	$ 42,068	$ 102,234	$ 115,267
Denominator for basic earnings per share (weighted average common shares outstanding)	16,133,310	16,253,704	16,180,261	16,240,966
Effect of dilutive options and warrants	84,570	121,278	80,848	114,824
Denominator for diluted earnings per share (weighted average common shares outstanding adjusted for the effect of dilutive options and warrants)	16,217,880	16,374,982	16,261,109	16,355,790
Basic earnings per common share	$ 2.29	$ 2.59	$ 6.32	$ 7.10
Diluted earnings per common share	$ 2.28	$ 2.57	$ 6.29	$ 7.05