Consolidated Statement of Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of period	$ 189,391
Other comprehensive income (loss)	(5,808)		(276,212)		110,857
Ending balance	183,550		189,391
Income before income taxes	952,196		698,888		701,928
Other operating costs and expenses	2,157,456		2,000,684		1,799,623
Federal and foreign income taxes	(302,593)		(193,587)		(191,285)
Net income before noncontrolling interests	649,603		505,301		510,643
Unrealized investment gains, before tax	72,889		(401,637)
Currency translation adjustments, before tax	(62,125)		(23,848)
Net pension asset, before tax	10,232		13,387		(1,575)
Other comprehensive income (loss), before tax	20,996		(412,098)
Unrealized investment gains, tax	(23,223)		140,573
Currency translation adjustments, tax	0		0
Net pension asset, tax	(3,581)		(4,687)
Other comprehensive income (loss), tax	(26,804)		135,886
Unrealized investment gains, net of tax	49,666		(261,064)
Change in unrealized translation adjustments	(62,125)		(23,848)		24,563
Net pension asset, net of tax	6,651		8,700
Unrealized investment gains (losses)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of period	256,566		517,658
Other comprehensive income (loss) before reclassifications	98,294		(193,188)
Amounts reclassified from AOCI	(48,628)		(67,876)
Other comprehensive income (loss)	49,666		(261,064)
Unrealized investment gain related to non-controlling interest	(33)		(28)
Ending balance	306,199		256,566
Unrealized investment gains (losses) | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net investment gains	(74,812)	[1]	(104,425)	[1]
Federal and foreign income taxes	26,184	[2]	36,549	[2]
Net income before noncontrolling interests	(48,628)		(67,876)
Currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of period	(60,524)		(36,676)
Other comprehensive income (loss) before reclassifications	(62,125)		(23,848)
Amounts reclassified from AOCI	0		0
Other comprehensive income (loss)	(62,125)		(23,848)
Ending balance	(122,649)		(60,524)		(36,676)
Change in unrealized translation adjustments	(62,125)		(23,848)		24,563
Currency translation adjustments | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income before income taxes	0		0
Federal and foreign income taxes	0		0
Net income before noncontrolling interests	0		0
Net pension asset
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of period	(6,651)		(15,351)
Other comprehensive income (loss) before reclassifications	0		0
Amounts reclassified from AOCI	6,651		8,700
Other comprehensive income (loss)	6,651		8,700
Ending balance	0		(6,651)
Net pension asset | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other operating costs and expenses	10,232	[3]	13,387	[3]
Federal and foreign income taxes	(3,581)	[2]	(4,687)	[2]
Net income before noncontrolling interests	6,651		8,700
Accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of period	189,391		465,631
Other comprehensive income (loss) before reclassifications	36,169		(217,036)
Amounts reclassified from AOCI	(41,977)		(59,176)
Other comprehensive income (loss)	(5,808)		(276,212)
Unrealized investment gain related to non-controlling interest	(33)		(28)
Ending balance	183,550		189,391
Accumulated other comprehensive income (loss) | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income before income taxes	(64,580)		(91,038)
Federal and foreign income taxes	22,603		31,862
Net income before noncontrolling interests	$ (41,977)		$ (59,176)

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

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

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