Short-Term Investments (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 24, 2012	Dec. 25, 2011
Schedule of Held-to-maturity Securities [Line Items]
Short-term investments	$ 279,858	$ 104,846
Held-to-maturity Securities, Debt Maturity, Date Range, Low	1 month
Held-to-maturity Securities, Debt Maturity, Date Range, High	8 months
Commercial Paper, Not Included with Cash and Cash Equivalents [Member]
Schedule of Held-to-maturity Securities [Line Items]
Carrying value of short-term investments	10,000
US Treasury Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Carrying value of short-term investments	$ 270,000

For an unclassified balance sheet, this item represents investments in debt securities which are categorized as held-to-maturity. The held-to-maturity category is for those securities that the entity has the positive intent and ability to hold until maturity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-Name Statement of Financial Accounting Standard (FAS)

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

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Reference 9: http://www.xbrl.org/2003/role/presentationRef

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Reference 10: http://www.xbrl.org/2003/role/presentationRef

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Reference 12: http://www.xbrl.org/2003/role/presentationRef

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+ Details