Investments (Estimated Fair Value Of Investments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Fixed maturity securities:
Due in one year or less	$ 403,269
Due after one year through five years	791,879
Due after five years through ten years	806,813
Due after ten years	2,029,562
Total	$ 4,031,523	$ 3,549,810
External credit rating, non investment grade [Member]
Credit Derivatives [Line Items]
Percentage of fixed maturities	0.40%