Statements of Comprehensive Income (Loss) Statements of Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period	$ 189,391
Other comprehensive income (loss)	69,510		(36,999)
Accumulated Other Comprehensive Income (Loss), End of Period	258,883
Net investment gains	52,754		19,969
Income before income taxes	247,585		160,223
Income before taxes	515,166		481,604
Tax effect	(77,901)		(43,625)
After-tax amounts reclassified	169,684		116,598
Unrealized investment gains, pre-tax	112,290		12,015
Unrealized investment gains, tax effect	(39,346)		(4,205)
Unrealized investment gains, after-tax amounts	72,944		7,810
Currency translation adjustment, pre-tax	(4,025)		(46,623)
Currency translation adjustment, tax effect	0		0
Change in unrealized currency translation adjustments	(4,025)		(46,623)
Net pension asset, pre-tax	909		2,792
Net pension asset, tax effect	(318)		(978)
Met pension asset, after-tax amounts	591		1,814
Other comprehensive income (loss), pre-tax	109,174		(31,816)
Other comprehensive income (loss), tax effect	(39,664)		(5,183)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period	256,566		517,658
Other comprehensive income (loss) before reclassifications	77,443		20,989
Amounts reclassified from AOCI	(4,499)		(13,179)
Other comprehensive income (loss)	72,944		7,810
Unrealized investment gain related to non-controlling interest	(18)		(40)
Accumulated Other Comprehensive Income (Loss), End of Period	329,492		525,428
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period	(60,524)		(36,676)
Other comprehensive income (loss) before reclassifications	(4,025)		(46,623)
Amounts reclassified from AOCI	0		0
Other comprehensive income (loss)	(4,025)		(46,623)
Accumulated Other Comprehensive Income (Loss), End of Period	(64,549)		(83,299)
Change in unrealized currency translation adjustments	(4,025)		(46,623)
Net Pension Asset [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period	(6,651)		(15,351)
Other comprehensive income (loss) before reclassifications	0		0
Amounts reclassified from AOCI	591		1,814
Other comprehensive income (loss)	591		1,814
Accumulated Other Comprehensive Income (Loss), End of Period	(6,060)		(13,537)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period	189,391		465,631
Other comprehensive income (loss) before reclassifications	73,418		(25,634)
Amounts reclassified from AOCI	(3,908)		(11,365)
Other comprehensive income (loss)	69,510		(36,999)
Unrealized investment gain related to non-controlling interest	(18)		(40)
Accumulated Other Comprehensive Income (Loss), End of Period	258,883		428,592
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Net investment gains	(6,921)	[1]	(20,075)	[1]
Tax effect	2,422	[2]	6,896	[2]
After-tax amounts reclassified	(4,499)		(13,179)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Income before income taxes	0		0
Tax effect	0		0
After-tax amounts reclassified	0		0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Pension Asset [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Income before taxes	909	[3]	2,792	[3]
Tax effect	(318)	[2]	(978)	[2]
After-tax amounts reclassified	591		1,814
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Income before income taxes	(6,012)		(17,283)
Tax effect	2,104		5,918
After-tax amounts reclassified	$ (3,908)		$ (11,365)

[1] Net investment gains in the consolidated statements of operations.

[2] Income tax expense in the consolidated statements of operations.

[3] Other operating costs and expenses in the consolidated statements of operations.