Accumulated Other Comprehensive Income (Loss) - Details About AOCI Components (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2015		Jun. 30, 2014	Jun. 30, 2015		Jun. 30, 2014
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	$ (85,884)		$ (72,587)	$ (150,633)		$ (91,706)
Tax benefit (expense)	(32,959)		5,654	(57,177)		(28,667)
Unrealized gains (losses) on investments
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(87,558)	[1]	(74,337)	(162,338)	[1]	(96,975)
OTTI losses recognized in AOCI
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	1,662		1,640	11,598		5,049
Underfunded pension liability
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	0		0	0		0
Cash flow hedge
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	12		110	107		220
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(85,884)		(72,587)	(150,633)		(91,706)
Tax benefit (expense)	3,682		3,695	3,766		4,035
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(82,202)		(68,892)	(146,867)		(87,671)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized gains (losses) on investments
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses) on investments sold	(71,027)		(107,470)	(149,578)		(132,384)
OTTI on investments	19,398		33,133	35,122		35,409
Total before tax	(87,558)		(74,337)	(162,338)		(96,975)
Tax benefit (expense)	3,694		3,699	3,781		4,152
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(83,864)		(70,638)	(158,557)		(92,823)
Reclassification out of Accumulated Other Comprehensive Income [Member] | OTTI losses recognized in AOCI
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses) on investments sold	1,594		1,386	11,469		3,344
OTTI on investments	68		254	129		1,705
Total before tax	1,662		1,640	11,598		5,049
Tax benefit (expense)	(12)		(4)	(15)		(117)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	1,650		1,636	11,583		4,932
Reclassification out of Accumulated Other Comprehensive Income [Member] | Cash flow hedge
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	12		110	107		220
Tax benefit (expense)	0		0	0		0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	12		110	107		220
Life Funds Withheld Assets
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses) on investments sold	68,037		624	120,775		624
OTTI on investments	(2,878)		(8,771)	(8,087)		(8,771)
Change in adjustments related to future policy benefit reserves, net of tax	(35,929)			(47,883)
Life Funds Withheld Assets | Unrealized gains (losses) on investments
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Change in adjustments related to future policy benefit reserves, net of tax			0			0
Life Funds Withheld Assets | Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized gains (losses) on investments
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Change in adjustments related to future policy benefit reserves, net of tax	$ (35,929)		$ 0	$ (47,882)		$ 0

[1] Included in these amounts is the impact of Shadow Adjustments. As of December 31, 2014 the cumulative impact of the Shadow Adjustments was $445.1 million. During the six months ended June 30, 2015, net movements of $(86.7) million were recorded, resulting in a total cumulative net impact of Shadow Adjustments on future policy benefit reserves of $358.4 million as of June 30, 2015.