Investments (Net Unrealized Gain (Loss) on Investments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Gross unrealized gains	$ 87,493	$ 157,304
Gross unrealized losses	(56,064)	(12,926)
Deferred policy acquisition costs and sales inducements	(12,804)	(62,856)
Deferred federal income tax expense	(6,519)	(28,556)
Adjustments for deferred expense, deferred policy acquisition and sales inducement cost	12,106	52,966
Net unrealized gains related to securities transferred to held to maturity	0	0
Net unrealized gains on investment securities	$ 12,106	$ 52,966