Investments (Changes in Net Unrealized Investment Gains Losses) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($)
Changes In Net Unrealized Investment Gains Losses Included In Accumulated Other Comprehensive Loss [Abstract]
Balance, beginning of period	$ 4,407
Unrealized investment gains (losses) during the period	10,126
Unrealized investment gains (losses) relating to [Abstract]
DAC and DSI	(3,800)
Deferred income tax benefit (expense)	(2,215)
Balance, end of period	8,518
Change in net unrealized investment gains (losses)	$ 4,111