Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net (loss) income		$ (7,015)	$ 74,953	$ 91,598	$ 169,703
Components of other comprehensive (loss) income
Unrealized holding gains (losses), net, arising on available-for-sale fixed maturity investments		(494,336)	261,039	(312,961)	572,337
Unrealized holding gains (losses), net, arising on cash flow hedges		(16,633)	3,010	522	3,894
Reclassification adjustment for (gains) losses, net, realized in net income		(5,038)	(6,536)	(35,475)	(28,754)
Net unrealized gains (losses) related to investments		(516,007)	257,513	(347,914)	547,477
Future policy benefits, DAC and VOBA adjustments		79,587	(29,720)	44,458	(86,968)
Employee benefit plan adjustment		2,934	0	5,537	0
Other comprehensive (loss) income before income taxes		(433,486)	227,793	(297,919)	460,509
Income tax (benefit) expense related to items of other comprehensive (loss) income		(151,720)	79,728	(104,272)	161,178
Other comprehensive income (loss)	[1]	(281,766)	148,065	(193,647)	299,331
Total comprehensive (loss) income		(288,781)	223,018	(102,049)	469,034
Non-credit component of impaired losses on fixed maturities available-for-sale		$ 1,314	$ (4,588)	$ (1,229)	$ (2,816)

[1] Other comprehensive (loss) income includes the non-credit component of impaired gains (losses), net, on fixed maturities available-for-sale in the amounts of $1,314 and $(4,588) for the three months ended June 30, 2015, and 2014, respectively, and $(1,229) and $(2,816) for the six months ended June 30, 2015, and 2014, respectively.