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Divestitures (Schedule of Results of Operations of Discontinued Operations) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Aug. 02, 2020	Apr. 26, 2020	Jan. 26, 2020	Oct. 27, 2019	Jul. 28, 2019	Apr. 28, 2019	Jan. 27, 2019	Oct. 28, 2018	Aug. 02, 2020	Jul. 28, 2019	Jul. 29, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Earnings (loss) from discontinued operations	$ 0	$ 2	$ 1,037	$ (3)	$ (3)	$ (39)	$ (235)	$ 14	$ 1,036	$ (263)	$ (463)
Campbell Fresh [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales										756	950
Disposal Group, Including Discontinued Operation, Operating Income (Loss)										(359)	(721)
Discontinued Operation, Tax Effect of Discontinued Operation										(78)	(142)
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
Earnings (loss) from discontinued operations										(332)	(579)
Campbell International [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales									359	1,046	1,120
Disposal Group, Including Discontinued Operation, Operating Income (Loss)									53	120	163
Discontinued Operation, Tax Effect of Discontinued Operation									17	41	47
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax									1,039	(12)	0
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation									39	(2)	0
Earnings (loss) from discontinued operations									1,036	69	116
Plant And Intangible Assets [Member] \| Campbell Fresh [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges										360	694
Plant And Intangible Assets [Member] \| Campbell International [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operations, Impairment charges									$ 0	$ 17	$ 0