Income Taxes - Aggregate Changes in Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 26, 2020	Sep. 28, 2019	Sep. 29, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balances	$ 15,619	$ 9,694	$ 8,407
Increases related to tax positions taken during a prior year	454	5,845	2,431
Decreases related to tax positions taken during a prior year	(791)	(686)	(2,212)
Increases related to tax positions taken during the current year	1,347	1,697	1,824
Decreases related to settlements with taxing authorities	(85)	(852)	(756)
Decreases related to expiration of the statute of limitations	(69)	(79)	0
Ending balances	$ 16,475	$ 15,619	$ 9,694

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of unrecognized tax benefits.

+ References

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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