Stock-Based Compensation - Weighted-Average Assumptions Utilized to Value Stock Options (Detail) - USD ($)	3 Months Ended	9 Months Ended
Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Share-based Payment Arrangement [Abstract]
Risk-free interest rate	1.70%	3.00%	1.70%	3.00%
Expected volatility	33.60%	34.30%	33.60%	34.30%
Expected life (in years)	4 years 9 months 18 days	4 years 9 months 18 days	4 years 9 months 18 days	4 years 9 months 18 days
Dividend yield	$ 0	$ 0	$ 0	$ 0
Weighted average fair value of options granted	$ 9.90	$ 15.07	$ 13.79	$ 13.51

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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

Rate of weighted-average expected volatility for award under share-based payment arrangement.

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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 award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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