Divestitures (Condensed Cash Flow Statement) (Details) - USD ($) $ in Millions	12 Months Ended
Aug. 02, 2020	Jul. 28, 2019	Jul. 29, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Depreciation and Amortization	$ 0	$ 83	$ 115
Net (gain) loss on sales of discontinued operations businesses	(1,039)	32
Payments to Acquire Property, Plant, and Equipment	299	384	407
Proceeds from Divestiture of Businesses, Net of Cash Divested	2,537	539	0
Asset Impairment Accelerated Depreciation [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges	0	377	694
Discontinued Operations, Held-for-sale or Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to Acquire Property, Plant, and Equipment	30	59	88
Proceeds from Divestiture of Businesses, Net of Cash Divested	$ 2,466	$ 539	$ 0

Amount before tax of income (loss) from a discontinued operation. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

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Amount of depreciation and amortization expense attributable to disposal group, including, but not limited to, discontinued operation.

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The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

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