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
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Income available to common shareholders	$ 42,831	$ 22,372
Denominator for basic earnings per share (weighted average common shares outstanding)	16,314,987	16,303,602
Effect of dilutive options and warrants	124,933	122,279
Denominator for diluted earnings per share (weighted average common shares outstanding adjusted for the effect of dilutive options and warrants)	16,439,920	16,425,881
Basic earnings per common share	$ 2.63	$ 1.37
Diluted earnings per common share	$ 2.61	$ 1.36