Accumulated Other Comprehensive Income - Details about AOCI components (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized and unrealized gains (losses) on derivative instruments		$ 53,123	$ 29,886	$ 7,798
Operating Expenses		(1,966,939)	(1,341,315)	(1,213,178)
Exchange gains (losses) before tax		(22,504)	37,568	28,243
Amounts reclassified from AOCI		(326,979)	(128,094)	(85,692)
Provision for income tax		19,161	(96,897)	(77,505)
Unrealized Gains (Losses) on Investments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI	[1]	(346,911)	(143,330)	(119,970)
OTTI Losses Recognized in AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI		18,987	14,082	32,193
Foreign Currency Translation Adjustments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI		0	87	206
Underfunded Pension Liability
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI		1,145	812	1,440
Cash Flow Hedge
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI		(200)	255	439
Life Funds Withheld Assets [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses) on investments sold		223,272	5,067	0
OTTI on investments		(13,357)	(20,587)	0
Net adjustments related to future policy benefit reserves, net of tax		(125,747)	(21,786)
Net realized and unrealized gains (losses) on derivative instruments		(151,691)	(488,222)	$ 0
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI		(326,979)	(128,094)
Provision for income tax		7,164	(1,974)
Total amount reclassified from AOCI, net of tax		(319,815)	(130,068)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Investments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses) on investments sold		(316,508)	(175,639)
OTTI on investments		95,344	54,095
Amounts reclassified from AOCI		(346,911)	(143,330)
Provision for income tax		7,597	(1,593)
Total amount reclassified from AOCI, net of tax		(339,314)	(144,923)
Reclassification out of Accumulated Other Comprehensive Income [Member] | OTTI Losses Recognized in AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses) on investments sold		18,014	11,848
OTTI on investments		973	2,234
Amounts reclassified from AOCI		18,987	14,082
Provision for income tax		(32)	(175)
Total amount reclassified from AOCI, net of tax		18,955	13,907
Reclassification out of Accumulated Other Comprehensive Income [Member] | Foreign Currency Translation Adjustments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI		0	87
Provision for income tax		0	0
Total amount reclassified from AOCI, net of tax		0	87
Reclassification out of Accumulated Other Comprehensive Income [Member] | Underfunded Pension Liability
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Operating Expenses		1,145	812
Provision for income tax		(401)	(206)
Total amount reclassified from AOCI, net of tax		744	606
Reclassification out of Accumulated Other Comprehensive Income [Member] | Cash Flow Hedge
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI		(200)	255
Provision for income tax		0	0
Total amount reclassified from AOCI, net of tax		(200)	255
Reclassification out of Accumulated Other Comprehensive Income [Member] | Life Funds Withheld Assets [Member] | Unrealized Gains (Losses) on Investments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net adjustments related to future policy benefit reserves, net of tax		$ (125,747)	$ (21,786)

[1] Included in these amounts is the impact of Shadow Adjustments. As of December 31, 2014, $445.1 million was recorded. During the year ended December 31, 2015, additional net impacts of $(170.7) million were recorded, resulting in a total cumulative net impact of Shadow Adjustments on future policy benefit reserves of $274.4 million at December 31, 2015.