Divestitures (Schedule of Results of Operations of Discontinued Operations) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jan. 31, 2021	Jan. 26, 2020	Jan. 31, 2021	Jan. 26, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Earnings (loss) from discontinued operations	$ 0	$ 1,037	$ 0	$ 1,034
Campbell International [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Revenue		136		359
Disposal Group, Including Discontinued Operation, Operating Income (Loss)		16		53
Discontinued Operation, Tax Effect of Discontinued Operation		4		17
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax		1,087		1,036
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation		62		38
Earnings (loss) from discontinued operations		$ 1,037		$ 1,034

Amount of tax expense (benefit) related to a discontinued operation. Includes, but is not limited to, tax expense (benefit) related to income (loss) from operations during the phase-out period, tax expense (benefit) related to gain (loss) on disposal, tax expense (benefit) related to gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and tax expense (benefit) related to adjustments of a prior period gain (loss) on disposal.

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- Definition

Amount after tax of income (loss) from a discontinued operation including the portion attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

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