Statements of Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012	Jun. 30, 2013		Jun. 30, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period				$ 465,631
Other comprehensive income (loss)	(218,402)		23,101	(255,401)		61,532
Accumulated Other Comprehensive Income (Loss), End of Period	210,225			210,225
Net investment gains	33,058		24,286	53,027		67,763
Income before income taxes	158,706		148,439	318,929		335,742
Income before taxes	494,286		448,758	975,890		880,537
Tax effect	43,579		39,535	87,204		91,606
After-tax amounts reclassified	115,127		108,904	231,725		244,136
Unrealized investment gains, pre-tax	(303,169)			(291,154)
Unrealized investment gains, tax effect	106,109			101,904
Unrealized investment gains, after-tax amounts	(197,060)			(189,250)
Currency translation adjustment, pre-tax	(23,156)			(69,779)
Currency translation adjustment, tax effect	0			0
Change in unrealized translation adjustments	(23,156)		(17,257)	(69,779)		(1,674)
Net pension asset, pre-tax	2,790			5,582
Net pension asset, tax effect	(976)			(1,954)
Met pension asset, after-tax amounts	1,814			3,628
Other comprehensive income (loss), pre-tax	(323,535)			(355,351)
Other comprehensive income (loss), tax effect	105,133			99,950
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	525,428			517,658
Other comprehensive income (loss) before reclassifications	(182,934)			(161,945)
Amounts reclassified from AOCI	(14,126)			(27,305)
Other comprehensive income (loss)	(197,060)			(189,250)
Unrealized investment gain related to non-controlling interest	35			(5)
Accumulated Other Comprehensive Income (Loss), End of Period	328,403			328,403
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period	(83,299)			(36,676)
Other comprehensive income (loss) before reclassifications	(23,156)			(69,779)
Amounts reclassified from AOCI	0			0
Other comprehensive income (loss)	(23,156)			(69,779)
Accumulated Other Comprehensive Income (Loss), End of Period	(106,455)			(106,455)
Change in unrealized translation adjustments				(69,779)		(1,674)
Net Pension Asset [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period	(13,537)			(15,351)
Other comprehensive income (loss) before reclassifications	0			0
Amounts reclassified from AOCI	1,814			3,628
Other comprehensive income (loss)	1,814			3,628
Accumulated Other Comprehensive Income (Loss), End of Period	(11,723)			(11,723)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning of Period	428,592			465,631
Other comprehensive income (loss) before reclassifications	(206,090)			(231,724)
Amounts reclassified from AOCI	(12,312)			(23,677)
Other comprehensive income (loss)	(218,402)			(255,401)
Unrealized investment gain related to non-controlling interest	35			(5)
Accumulated Other Comprehensive Income (Loss), End of Period	210,225			210,225
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	(21,933)	[1]		(42,008)	[1]
Tax effect	7,807	[2]		14,703	[2]
After-tax amounts reclassified	(14,126)			(27,305)
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	2,790	[3]		5,582	[3]
Tax effect	(976)	[2]		(1,954)	[2]
After-tax amounts reclassified	1,814			3,628
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	(19,143)			(36,426)
Tax effect	6,831			12,749
After-tax amounts reclassified	$ (12,312)			$ (23,677)

[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.