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		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Earnings Per Share [Abstract]
Income available to common shareholders	$ 34,324	$ 39,132	$ 73,199	$ 81,963
Denominator for basic earnings per share (weighted average common shares outstanding)	16,249,307	16,340,690	16,234,598	16,327,838
Effect of dilutive options and warrants	111,939	132,110	111,543	127,835
Denominator for diluted earnings per share (weighted average common shares outstanding adjusted for the effect of dilutive options and warrants)	16,361,246	16,472,800	16,346,141	16,455,673
Basic earnings per common share	$ 2.11	$ 2.39	$ 4.51	$ 5.02
Diluted earnings per common share	$ 2.10	$ 2.38	$ 4.48	$ 4.98