Investments (Amortized Cost And Estimated Fair Value Of Debt Securities By Contractual Maturity) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Investments [Abstract]
Securities Available-for-Sale, Due in one year or less, Cost	$ 2,905
Securities Available-for-Sale, Due after one year through five years, Cost	50,712
Securities Available-for-Sale, Due after five years through ten years, Cost	530,300
Securities Available-for-Sale, Due after ten years, Cost	1,089,947
Securities Available-for-Sale, Cost, Total	1,673,864	$ 1,384,607
Securities Available-for-Sale, Due in one year or less, Estimated Fair Value	2,896
Securities Available-for-Sale, Due after one year through five years, Estimated Fair Value	48,401
Securities Available-for-Sale, Due after five years through ten years, Estimated Fair Value	490,723
Securities Available-for-Sale, Due after ten years, Estimated Fair Value	963,500
Debt Securities, Available-for-sale, Total	$ 1,505,520	$ 1,408,165