Investments (Realized Investment Gains Losses Net) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	$ 55,151	$ 59,025
Fixed maturities
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	(14,924)	2,114
Equity securities
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	0	0
Commercial mortgage and other loans
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	562	151
Joint ventures and limited partnerships
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	(148)	38
Derivatives
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	69,647	56,720
Other
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	$ 14	$ 2