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, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Income available to common shareholders	$ 39,132	$ 29,505	$ 81,963	$ 51,877
Denominator for basic earnings per share (weighted average common shares outstanding)	16,340,690	16,296,427	16,327,838	16,300,015
Effect of dilutive options and warrants	132,110	79,007	127,835	100,642
Denominator for diluted earnings per share (weighted average common shares outstanding adjusted for the effect of dilutive options and warrants)	16,472,800	16,375,434	16,455,673	16,400,657
Basic earnings per common share	$ 2.39	$ 1.81	$ 5.02	$ 3.18
Diluted earnings per common share	$ 2.38	$ 1.80	$ 4.98	$ 3.16