Fair Value Option (Gains And Losses Due To Changes In Fair Value Of Investments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
(Losses) gains due to changes in fair value of investments	$ (18,538)	$ (20,528)	$ (64,205)	$ 66,583
Fixed maturity securities [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
(Losses) gains due to changes in fair value of investments	(1,602)	3,536	(30,609)	73,149
Equity Securities [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
(Losses) gains due to changes in fair value of investments	(16,938)	(23,995)	(34,234)	(6,355)
Short-term investments [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
(Losses) gains due to changes in fair value of investments	$ 2	$ (69)	$ 638	$ (211)