Income Taxes - Reconciliation of Beginning and Ending Amount of Gross Unrecognized Tax Benefits, Excluding Related Accrual for Interest (Detail) - USD ($) $ in Millions	12 Months Ended
Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at the beginning of the year	$ 648	$ 832	$ 844
Increase due to business acquisitions	2,728	0	0
Increases for current year tax positions	84	64	61
Increases for prior year tax positions	143	48	13
Decreases in prior year tax positions	(61)	(135)	(55)
Settlements with taxing authorities	(590)	(161)	(31)
Balance at the end of the year	$ 2,952	$ 648	$ 832

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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- Definition

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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- Definition

Amount of increase in unrecognized tax benefits resulting from acquisitions.

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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 increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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