Divestitures (Narrative) (Details) £ in Millions, $ in Millions			3 Months Ended									12 Months Ended
	Dec. 23, 2019 USD ($)	Sep. 23, 2019 USD ($)	Aug. 02, 2020 USD ($)	Apr. 26, 2020 USD ($)	Jan. 26, 2020 USD ($)	Oct. 27, 2019 USD ($)	Oct. 27, 2019 GBP (£)	Jul. 28, 2019 USD ($)	Apr. 28, 2019 USD ($)	Jan. 27, 2019 USD ($)	Oct. 28, 2018 USD ($)	Aug. 02, 2020 USD ($)	Jul. 28, 2019 USD ($)	Jul. 29, 2018 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales			$ 2,108	$ 2,238	$ 2,162	$ 2,183		$ 1,780	$ 1,953	$ 2,172	$ 2,202	$ 8,691	$ 8,107	$ 6,615
Net (gain) loss on sale of business												975	(32)	0
Bolthouse Farms carrot and carrot ingredients [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of Intangible Assets, Finite-lived										55
Bolthouse Farms refrigerated beverages and salad dressing [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of Intangible Assets, Finite-lived										22
Garden Fresh Gourmet [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of Intangible Assets, Finite-lived										39
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
Campbell Fresh [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax													(32)	0
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation													19	0
Campbell Fresh [Member] | Deferred tax asset write-off [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] | 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] | 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 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] | 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 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] | 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] | 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] | 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
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] | 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] | 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
Kelsen [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses		$ 322
Kelsen [Member] | Trademarks [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges								7
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	$ 129	$ 44
Net (gain) loss on sale of business						$ (64)
European Chips Business [Member] | Customer Relationships [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of Intangible Assets, Finite-lived								$ 16