Investments (Gains And Losses Due To Changes In Fair Value Of Investments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Fixed maturity securities
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total gains	$ (260,223)	$ (39,649)	$ 41,394
Equity securities
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total gains	(185,694)	107,701	32,232
Short-term investments
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total gains	88	(141)	(1,014)
Investments
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total gains	$ (445,829)	$ 67,911	$ 72,612