Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net earnings	$ 127,606us-gaap_NetIncomeLoss	$ 111,931us-gaap_NetIncomeLoss
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments (net of tax of $0 in 2015 and 2014)	(19,450)	(4,837)
Change in marketable securities (net of tax of $0 in 2015 and 2014)	0	2
Comprehensive income	$ 108,156us-gaap_ComprehensiveIncomeNetOfTax	$ 107,096us-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 gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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