Stockholders' Equity, Equity Incentive Plans (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
Sep. 26, 2020	Sep. 28, 2019	Sep. 29, 2018
Stockholders' Equity [Abstract]
Stock-based compensation expense	$ 33	$ 27	$ 23
Intrinsic value of options exercised	$ 28
2015 Plan [Member]
Stockholders' Equity [Abstract]
Shares authorized for grant (in shares)			12.5
Increase in shares authorized for grant (in shares)			5.0

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Number of additional shares authorized for issuance under share-based payment arrangement.

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Number of shares authorized for issuance under share-based payment arrangement.

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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.

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