Investments (Amortized Cost And Estimated Fair Value Of Debt Securities By Contractual Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Amortized Cost
Due in one year or less	$ 2,401
Due after one year through five years	143,021
Due after five years through ten years	360,136
Due after ten years	1,067,573
Total	1,573,131	$ 1,479,545
Estimated Fair Value
Due in one year or less	2,388
Due after one year through five years	138,928
Due after five years through ten years	344,318
Due after ten years	977,161
Total	$ 1,462,795	$ 1,338,137