Divestitures (Condensed Cash Flow Statement) (Details) - USD ($) $ in Millions		3 Months Ended
		Oct. 27, 2019	Oct. 28, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Losses on sales of discontinued operations businesses		$ (104)	$ 0
Payments to Acquire Property, Plant, and Equipment		98	111
Proceeds from Divestiture of Businesses, Net of Cash Divested		368	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	14
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]
Disposal Group, Including Discontinued Operation, Depreciation and Amortization	[1]	0	27
Losses on sales of discontinued operations businesses		40	0
Payments to Acquire Property, Plant, and Equipment		21	22
Proceeds from Divestiture of Businesses, Net of Cash Divested		$ 297	$ 0

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