Divestitures (Narrative) (Details) £ in Millions, $ in Millions			3 Months Ended							6 Months Ended
	Dec. 23, 2019 USD ($)	Sep. 23, 2019 USD ($)	Jan. 31, 2021 USD ($)		Apr. 26, 2020 USD ($)	Jan. 26, 2020 USD ($)		Oct. 27, 2019 USD ($)	Oct. 27, 2019 GBP (£)	Jan. 31, 2021 USD ($)		Jan. 26, 2020 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales			$ 2,279			$ 2,162				$ 4,619		$ 4,345
Net (gain) loss on sale of business										0		(972)
Taxes on earnings			102			33				199		101
Kelsen [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses		$ 322
Arnott's and International [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses	$ 2,286				$ 4
European chips business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses								$ 77	£ 63
Net sales												25
Net (gain) loss on sale of business			$ 0	[1]		0	[1]	$ 64		$ 0	[1]	$ 64	[1]
European chips business [Member] | Continuing Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Taxes on earnings						$ (19)

[1] See Note 3 for additional information.