Investments (Realized Investment Gains Losses Net) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	$ (60,640)	$ 56,061	$ (61,563)	$ 84,076
Fixed Maturities [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	2,056	6,959	15,912	52,624
Equity Securities [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	703	2,039	703	1,996
Commercial Mortgage Loans [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	(483)	439	(588)	5,114
Derivative [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	(62,916)	46,731	(77,590)	24,451
Other [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	$ 0	$ (107)	$ 0	$ (109)