Investments (Realized Investment Gains Losses Net) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	$ 35,160	$ 29,874	$ (923)	$ 28,014
Fixed Maturities [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	6,790	30,100	13,857	45,665
Equity Securities [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	0	(43)	0	(43)
Commercial Mortgage and Other Loans [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	451	5,149	(105)	4,673
Derivatives [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	27,919	(5,332)	(14,675)	(22,281)
Other [Member]
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	$ 0	$ 0	$ 0	$ 0