Divestitures (Narrative) (Details) £ in Millions, $ in Millions		3 Months Ended							9 Months Ended
		Apr. 26, 2020 USD ($)	Jan. 26, 2020 USD ($)	Oct. 27, 2019 USD ($)	Jul. 28, 2019 USD ($)	Apr. 28, 2019 USD ($)	Jan. 27, 2019 USD ($)	Oct. 28, 2018 USD ($)	Apr. 26, 2020 GBP (£)	Apr. 26, 2020 USD ($)	Apr. 28, 2019 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales		$ 2,238				$ 1,953				$ 6,583	$ 6,327
Net (gain) loss on sale of business										975	(18)
Taxes on earnings		52				33				153	147
Bolthouse Farms [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation						29
Campbell Fresh [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges						0					360
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation						23					21
Campbell Fresh [Member] | U.S Refrigerated Soup & Garden Fresh Gourmet [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses						55
Campbell Fresh [Member] | Bolthouse Farms [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses					$ 500
Campbell Fresh [Member] | U.S. Refrigerated Soup [Member] | Property, Plant and Equipment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges								$ 14
Campbell Fresh [Member] | Bolthouse Farms carrot and carrot ingredients [Member] | Property, Plant and Equipment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges							$ 104
Campbell Fresh [Member] | Bolthouse Farms carrot and carrot ingredients [Member] | Trademarks [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges							18
Campbell Fresh [Member] | Bolthouse Farms carrot and carrot ingredients [Member] | Customer Relationships [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges							40
Campbell Fresh [Member] | Bolthouse Farms carrot and carrot ingredients [Member] | Technology-Based Intangible Assets [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges							15
Campbell Fresh [Member] | Bolthouse Farms refrigerated beverages and salad dressing [Member] | Property, Plant and Equipment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges							9
Campbell Fresh [Member] | Bolthouse Farms refrigerated beverages and salad dressing [Member] | Trademarks [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges							74
Campbell Fresh [Member] | Bolthouse Farms refrigerated beverages and salad dressing [Member] | Customer Relationships [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges							22
Campbell Fresh [Member] | Garden Fresh Gourmet [Member] | Property, Plant and Equipment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges							2
Campbell Fresh [Member] | Garden Fresh Gourmet [Member] | Trademarks [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges							23
Campbell Fresh [Member] | Garden Fresh Gourmet [Member] | Customer Relationships [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges							$ 39
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		4	$ 2,286
European chips business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses									£ 63	77
Net sales						33				25	93
Net (gain) loss on sale of business	[1]	0				$ 0				$ (64)	$ 0
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