Employee Stock Plans - Additional Information (Detail) $ in Millions	9 Months Ended
Jul. 03, 2015 USD ($) performance_period shares	Feb. 08, 2012 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares counted against the available for grant		2.5
Stock options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense related to outstanding stock awards \| $	$ 13.6
Weighted average period unrecognized compensation expense is expected to be recognized, years	1 year 8 months 16 days
Restricted stocks, restricted stock units, deferred stock units and performance units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense related to outstanding stock awards \| $	$ 44.3
Weighted average period unrecognized compensation expense is expected to be recognized, years	1 year 9 months 26 days
Third Amended and Restated 2005 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares counted against the available for grant	2.6
Third Amended and Restated 2005 Plan \| Performance units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award service period	3 years
Number of performance periods \| performance_period	1
Performance period term	3 years
Third Amended and Restated 2005 Plan \| Performance units, company performance
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance period term	1 year
Third Amended and Restated 2005 Plan \| Performance units, total shareholder return performance
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance period term	3 years

Unrecognized cost of unvested share-based compensation awards.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (i)

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

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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

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

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