Investments (Realized Investment Gains Losses Net) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	$ (38,096)	$ (36,083)
Fixed Maturities [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	2,712	7,068
Equity Securities [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	1	0
Commercial Mortgage Loans [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	38	(556)
Derivative [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	(40,826)	(42,595)
Other [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	$ (21)	$ 0