Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 37,796us-gaap_ProfitLoss	$ 21,852us-gaap_ProfitLoss
Other comprehensive income (loss), net of tax:
Unrealized gain on securities	20,073	12,200
Foreign currency translation adjustment	(18,660)	(6,040)
Pension benefit adjustment	4,600	3,891
Total other comprehensive income (loss), net of tax	6,013	10,051
Comprehensive income	43,809	31,903
Less: Comprehensive income attributable to noncontrolling interests	162	131
Comprehensive income attributable to the Company	$ 43,647us-gaap_ComprehensiveIncomeNetOfTax	$ 31,772us-gaap_ComprehensiveIncomeNetOfTax

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax and reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

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Amount after tax and reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.

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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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