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, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Income available to common shareholders	$ 21,039	$ 21,810	$ 40,083	$ 41,387
Denominator for basic earnings per share (weighted average common shares outstanding)	15,370,882	15,392,435	15,375,026	15,396,770
Effect of dilutive options and warrants	36,999	19,732	36,894	16,798
Denominator for diluted earnings per share (weighted average common shares outstanding adjusted for the effect of dilutive options and warrants)	15,407,881	15,412,167	15,411,920	15,413,568
Basic earnings per common share	$ 1.37	$ 1.42	$ 2.61	$ 2.69
Diluted earnings per common share	$ 1.37	$ 1.42	$ 2.60	$ 2.69