Investment Securities (Amortized Cost And Fair Value Of Investment Securities By Contractual Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Available-for-sale, Amortized cost [Abstract]
Due before one year	$ 1,215
Due after one year through five years	156,589
Due after five years through ten years	238,612
Due after ten years	642,734
Total	1,039,150	$ 1,181,906
Available-for-sale, Fair value [Abstract]
Due before one year	1,214
Due after one year through five years	164,150
Due after five years through ten years	241,810
Due after ten years	647,049
Debt Securities, Available-for-sale, Total	$ 1,054,223	$ 1,206,164