Stock Activity Related To Stock Options Exercised (Detail) - USD ($) $ in Thousands	12 Months Ended
Sep. 28, 2018	Sep. 29, 2017	Sep. 30, 2016
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Tax benefits related to stock options exercised	$ 500	$ 2,100	$ 600
Stock Options
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Proceeds from stock options exercised	1,609	28,116	8,175
Tax benefits related to stock options exercised	109	2,271	406
Intrinsic value of stock options exercised	$ 582	$ 19,223	$ 3,195

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- Definition

Amount of tax benefit from exercise of stock options granted under share-based compensation arrangement.

+ References

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- Definition

Amount of cash inflow from exercise of stock options granted under share-based compensation arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=SL79508275-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585

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- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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