Investments (Amortized Cost And Estimated Fair Value Of Debt Securities By Contractual Maturity) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Amortized Cost
Due in one year or less	$ 1,814
Due after one year through five years	51,378
Due after five years through ten years	511,736
Due after ten years	1,021,942
Total	1,586,870	$ 1,673,864
Estimated Fair Value
Due in one year or less	1,796
Due after one year through five years	47,776
Due after five years through ten years	472,381
Due after ten years	897,980
Total	$ 1,419,933	$ 1,505,520