CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) In Thousands, unless otherwise specified	12 Months Ended
Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Statement of Stockholders' Equity [Abstract]
Issuance of common stock under employee stock purchase plan (in shares)	79	87	96
Exercise of stock options (in shares)	1,179	2,681	2,133
Exercise of restricted stock units (in shares)	135	166	360
Repurchase of common stock (in shares)	4,664us-gaap_TreasuryStockSharesAcquired	2,287us-gaap_TreasuryStockSharesAcquired	6,112us-gaap_TreasuryStockSharesAcquired

Number of share instruments newly issued under a share-based compensation plan.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

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Number of shares issued during the period as a result of an employee stock purchase plan.

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Number of share options (or share units) exercised during the current period.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

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-Section 04

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

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Number of shares that have been repurchased during the period and are being held in treasury.

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