Investments (Balance of and Changes in AOCI Components) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), Beginning Balance	$ 84,622
Income tax benefit (expense)	8,285	$ (8,604)	$ (332,372)
Accumulated other comprehensive income (loss), Ending Balance	46,166	84,622
Foreign Currency Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), Beginning Balance	(30)	10	7
Change in component during period	(54)	(40)	3
Amounts reclassified from AOCI	0
Income tax benefit (expense)	19
Accumulated other comprehensive income (loss), Ending Balance	(65)	(30)	10
Net Unrealized Investment Gains (Losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), Beginning Balance	84,652	70,857	147,280
Change in component during period	(54,279)	13,795	(76,423)
Amounts reclassified from AOCI	(4,831)	(14,706)	(8,805)
Income tax benefit (expense)	20,689
Accumulated other comprehensive income (loss), Ending Balance	46,231	84,652	70,857
Cash Flow Hedge Gain Loss To AOCI	14,800	5,000	(4,000)
Total Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss), Beginning Balance	84,622	70,867	147,287
Change in component during period	(54,333)	13,755	(76,420)
Amounts reclassified from AOCI	(4,831)	(14,706)	(8,805)
Income tax benefit (expense)	20,708
Accumulated other comprehensive income (loss), Ending Balance	$ 46,166	$ 84,622	$ 70,867