Investments (Components Of Realized Gains And Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Gain (Loss) on Investments [Line Items]
Gross realized gains on sale of invested assets									$ 213,618	$ 183,592	$ 154,941
Gross realized losses on sale of invested assets									(106,321)	(51,702)	(62,169)
Net realized and unrealized losses on derivatives									9,485	(3,608)	(70,090)
Net realized investment gains	67,599	27,487	(115,198)	79,637	14,379	149,813	8,663	133,581	59,525	306,436	10,077
Proceeds from sale of available for sale securities									0	236,336	646,479
Debt Securities [Member]
Gain (Loss) on Investments [Line Items]
Mark-to-market changes									(117,577)	106,328	(8,078)
Equity securities [Member]
Gain (Loss) on Investments [Line Items]
Mark-to-market changes									4,288	33,018	775
Other invested assets [Member]
Gain (Loss) on Investments [Line Items]
Mark-to-market changes									$ 56,032	$ 38,808	$ (5,302)