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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
(Losses) gains due to changes in fair value of investments	$ (21,132)	$ (18,538)	$ 34,527	$ (64,205)
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	(19,521)	(1,602)	20,913	(30,609)
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	(2,143)	(16,938)	13,430	(34,234)
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	$ 532	$ 2	$ 184	$ 638