Acquisitions (Details) (USD $)	12 Months Ended					1 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Jan. 31, 2013
Business Acquisition [Line Items]
Accumulated other comprehensive income	$ 183,550,000		$ 189,391,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Premium and service fee receivable	150,944,000		110,146,000
Deferred federal and foreign income taxes	37,452,000		0
Proceeds from Sales of Business, Affiliate and Productive Assets	15,783,000
Assets of Disposal Group, Including Discontinued Operation	15,000,000
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net	4,000,000
Disposal Group, Including Discontinued Operation, Goodwill	7,000,000
Disposal Group, Including Discontinued Operation, Other Assets	6,000,000
Disposal Group, Including Discontinued Operation, Liabilities of Disposal Group	2000
Other Comprehensive Income (Loss), Net of Tax	(5,808,000)		(276,212,000)		110,857,000
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	952,196,000		698,888,000		701,928,000
Other Cost and Expense, Operating	2,157,456,000		2,000,684,000		1,799,623,000
Income Tax expense	(302,593,000)		(193,587,000)		(191,285,000)
Net income (loss)	649,603,000		505,301,000		510,643,000
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax	72,889,000		(401,637,000)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	(62,125,000)		(23,848,000)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	10,232,000		13,387,000		(1,575,000)
Other Comprehensive Income (Loss), before Tax	20,996,000		(412,098,000)
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax	(23,223,000)		140,573,000
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	0		0
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax	(3,581,000)		(4,687,000)
Other Comprehensive Income (Loss), Tax	(26,804,000)		135,886,000
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	49,666,000		(261,064,000)
Net change in period	(62,125,000)		(23,848,000)		24,563,000
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	6,651,000		8,700,000
Worldwide Supplier of After-market (OEM) Parts [Member]
Business Acquisition [Line Items]
Business acquisition, cost of acquired entity, cash paid					43,000,000	43,000,000
Business Acquisition, Percentage of Voting Interests Acquired			100.00%		0.00%
Indefinite-lived Intangible Assets Acquired			3,000,000
London Acquisition, Inactive insurance Company, and Worldwide Supplier of After-market (OEM) Parts [Member]
Business Acquisition [Line Items]
Indefinite-lived Intangible Assets Acquired	10,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Cash and cash equivalents	17,457,000		3,911,000
Real estate, furniture and equipment	669,000		898,000
Goodwill and other intangibles assets	79,646,000		64,464,000
Premium and service fee receivable	24,432,000		0
Other assets	2,590,000		60,661,000
Total assets acquired	124,794,000		129,934,000
Deferred federal and foreign income taxes	(7,107,000)		0
Debt	0		(27,612,000)
Other liabilities assumed	(34,809,000)		(17,076,000)
Net assets acquired	(82,878,000)		(85,246,000)
Minimum | Worldwide Supplier of After-market (OEM) Parts [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	2 years
Maximum | Worldwide Supplier of After-market (OEM) Parts [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	15 years
Unrealized investment gains (losses)
Business Acquisition [Line Items]
Accumulated other comprehensive income	306,199,000		256,566,000		517,658,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Other comprehensive income (loss) before reclassifications	98,294,000		(193,188,000)
Amounts reclassified from AOCI	(48,628,000)		(67,876,000)
Other Comprehensive Income (Loss), Net of Tax	49,666,000		(261,064,000)
Unrealized investment gain related to non-controlling interest	(33,000)		(28,000)
Currency translation adjustments
Business Acquisition [Line Items]
Accumulated other comprehensive income	(122,649,000)		(60,524,000)		(36,676,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Other comprehensive income (loss) before reclassifications	(62,125,000)		(23,848,000)
Amounts reclassified from AOCI	0		0
Other Comprehensive Income (Loss), Net of Tax	(62,125,000)		(23,848,000)
Net change in period	(62,125,000)		(23,848,000)		24,563,000
Net pension asset
Business Acquisition [Line Items]
Accumulated other comprehensive income	0		(6,651,000)		(15,351,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Other comprehensive income (loss) before reclassifications	0		0
Amounts reclassified from AOCI	6,651,000		8,700,000
Other Comprehensive Income (Loss), Net of Tax	6,651,000		8,700,000
Accumulated other comprehensive income (loss)
Business Acquisition [Line Items]
Accumulated other comprehensive income	183,550,000		189,391,000		465,631,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Other comprehensive income (loss) before reclassifications	36,169,000		(217,036,000)
Amounts reclassified from AOCI	(41,977,000)		(59,176,000)
Other Comprehensive Income (Loss), Net of Tax	(5,808,000)		(276,212,000)
Unrealized investment gain related to non-controlling interest	(33,000)		(28,000)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized investment gains (losses)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Marketable Securities, Realized Gain (Loss), Excluding Other than Temporary Impairments	(74,812,000)	[1]	(104,425,000)	[1]
Income Tax expense	26,184,000	[2]	36,549,000	[2]
Net income (loss)	(48,628,000)		(67,876,000)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Currency translation adjustments
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	0		0
Income Tax expense	0		0
Net income (loss)	0		0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net pension asset
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Other Cost and Expense, Operating	10,232,000	[3]	13,387,000	[3]
Income Tax expense	(3,581,000)	[2]	(4,687,000)	[2]
Net income (loss)	6,651,000		8,700,000
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated other comprehensive income (loss)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	(64,580,000)		(91,038,000)
Income Tax expense	22,603,000		31,862,000
Net income (loss)	$ (41,977,000)		$ (59,176,000)

[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.