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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Income available to common shareholders	$ 29,505	$ 22,163	$ 51,877	$ 47,618
Denominator for basic earnings per share (weighted average common shares outstanding)	16,296,427	16,560,545	16,300,015	16,106,043
Effect of dilutive options and warrants	79,007	82,026	100,642	87,600
Denominator for diluted earnings per share (weighted average common shares outstanding adjusted for the effect of dilutive options and warrants)	16,375,434	16,642,571	16,400,657	16,193,643
Basic earnings per common share	$ 1.81	$ 1.34	$ 3.18	$ 2.96
Diluted earnings per common share	$ 1.80	$ 1.33	$ 3.16	$ 2.94