Stockholders' Equity and Stock-Based Compensation - Black-Scholes Model Weighted Average Assumptions Used to Estimate Fair Value of Shares to Be Issued as of Grant Date (Detail) (USD $)	12 Months Ended
Sep. 29, 2012	Sep. 24, 2011	Sep. 25, 2010
Assumptions:
Risk-free interest rates	0.70%	1.00%	1.80%
Expected life (in years)	4 years 3 months 18 days	4 years 2 months 12 days	3 years 10 months 24 days
Expected volatility	47.00%	45.00%	47.00%
Dividend yield
Employee stock purchase plan [Member]
Assumptions:
Risk-free interest rates	0.16%
Expected life (in years)	6 months
Expected volatility	35.00%
Dividend yield

The range of expected volatilities used and the weighted-average expected volatility for an entity using a valuation technique with different volatilities during the contractual term.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (f)(2)(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph e(2)(b)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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