Income Taxes - Aggregate Changes in Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
Jul. 25, 2020	Jul. 27, 2019	Jul. 28, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 1,925	$ 2,000	$ 1,973
Additions based on tax positions related to the current year	188	185	251
Additions for tax positions of prior years	554	84	84
Reductions for tax positions of prior years	(136)	(283)	(129)
Settlements	(4)	(38)	(124)
Lapse of statute of limitations	(9)	(23)	(55)
Ending balance	$ 2,518	$ 1,925	$ 2,000

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

+ References

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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 increase 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 lapses of applicable statutes of limitations.

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