Securities Available For Sale (Summary Of Maturities Distribution Of The Amortized Cost And Estimated Fair Value Of Securities Available For Sale) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Securities Available For Sale [Abstract]
Amortized Cost, Due one year or less	$ 179
Amortized Cost, Due after one year through five years	5,529
Amortized Cost, Due after five years through ten years	13,654
Amortized Cost, Due after ten years	498,839
Securities Available for Sale, Amortized Cost	518,201	$ 496,179
Estimated Fair Value, Due one year or less	181
Estimated Fair Value, Due after one year through five years	5,634
Estimated Fair Value, Due after five years through ten years	14,361
Estimated Fair Value, Due after ten years	512,743
Securities Available for Sale, Estimated Fair Value	$ 532,919	$ 504,969