Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 22, 2015	Mar. 23, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 46,289us-gaap_NetIncomeLoss	$ 40,474us-gaap_NetIncomeLoss
Other comprehensive loss, before tax:
Currency translation adjustment	(810)	(1,026)
Tax attributes of items in other comprehensive loss:
Currency translation adjustment	381	442
Other comprehensive loss, net of tax	(429)	(584)
Comprehensive income	$ 45,860us-gaap_ComprehensiveIncomeNetOfTax	$ 39,890us-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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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount before tax, after 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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Amount of tax expense (benefit), after 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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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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