Divestitures (Condensed Cash Flow Statement) (Details) - USD ($) $ in Millions		9 Months Ended
		Apr. 26, 2020	Apr. 28, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Depreciation and Amortization	[1]	$ 0	$ 72
Discontinued Operation, net (gain) loss on sales of businesses		(1,039)	18
Payments to Acquire Property, Plant, and Equipment		220	274
Proceeds from Divestiture of Businesses, Net of Cash Divested		2,537	54
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	360
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	45
Proceeds from Divestiture of Businesses, Net of Cash Divested		$ 2,466	$ 54

[1] Depreciation and amortization are no longer recognized once businesses are classified as held for sale/discontinued operations.