Stock-Based Compensation - Weighted-Average Assumptions Utilized to Value Stock Options (Detail) - USD ($)	3 Months Ended
Dec. 29, 2018	Dec. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk-free interest rate	3000000.00%	2.10%
Expected volatility	34.30%	35.30%
Expected life (in years)	4 years 9 months 8 days	4 years 8 months 8 days
Dividend yield	$ 0	$ 0
Weighted average fair value of options granted	$ 13.41	$ 13.00

No definition available.

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

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- Definition

Disclosure of the weighted average expected dividend for an entity using a valuation technique with different dividend rates during the contractual term.

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- Definition

Weighted average expected volatility rate of share-based compensation awards.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ 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 (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
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-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

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