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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Income available to common shareholders	$ 31,146	$ 24,762	$ 78,764	$ 84,126
Denominator for basic earnings per share (weighted average common shares outstanding)	16,382,798	15,686,542	16,198,294	15,420,135
Effect of dilutive options and warrants	92,943	146,192	89,401	140,531
Denominator for diluted earnings per share (weighted average common shares outstanding adjusted for the effect of dilutive options and warrants)	16,475,741	15,832,734	16,287,695	15,560,666
Basic earnings per common share	$ 1.90	$ 1.58	$ 4.86	$ 5.46
Diluted earnings per common share	$ 1.89	$ 1.56	$ 4.84	$ 5.41