Investments (Realized Investment Gains Losses Net) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	$ (208,538)	$ 114,067	$ (13,450)
Fixed maturities
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	9,505	17,563	33,440
Equity securities
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	397	1,085	480
Commercial mortgage and other loans
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	1,503	4,644	5,494
Joint ventures and limited partnerships
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	320	210	(83)
Derivatives
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	(220,292)	90,556	(52,799)
Other
Schedule Of Gain Loss On Investments [Line Items]
Realized investment gains (losses), net	$ 29	$ 9	$ 18