Investments (Balance of and Changes in AOCI Components) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance		$ 178,691
Balance	$ 95,100	95,100		$ 178,691
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance		(67)	$ 403	403
Change in other comprehensive income (loss) before reclassifications		(338)	(36)
Amounts reclassified from AOCI		0	0
Income tax benefit (expense)		118	13
Balance	(287)	(287)	380	(67)	$ 403
Total net unrealized investment gains (losses)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance		178,758	56,243	56,243
Change in other comprehensive income (loss) before reclassifications		(123,909)	170,185
Amounts reclassified from AOCI	(1,930)	(4,044)	(5,920)
Income tax benefit (expense)		44,582	(57,493)
Balance	95,387	95,387	163,015	178,758	56,243
Cash Flow Hedge Gain (Loss) To AOCI		24,000	(7,000)	12,000	(5,000)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance		178,691	56,646	56,646
Change in other comprehensive income (loss) before reclassifications		(124,247)	170,149
Amounts reclassified from AOCI	(1,930)	(4,044)	(5,920)
Income tax benefit (expense)		44,700	(57,480)
Balance	$ 95,100	$ 95,100	$ 163,395	$ 178,691	$ 56,646