Financial Instruments (Derivatives Not Designated As Hedges) (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 01, 2021	Aug. 02, 2020	Jul. 28, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Gain) or Loss Recognized in Earnings on Derivatives	$ (61)	$ 8	$ 3
Foreign Exchange Contract [Member] | Cost Of Products Sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Gain) or Loss Recognized in Earnings on Derivatives	2	(1)	0
Foreign Exchange Contract [Member] | Other Expenses/Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Gain) or Loss Recognized in Earnings on Derivatives	0	2	0
Commodity Derivative Contracts [Member] | Cost Of Products Sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Gain) or Loss Recognized in Earnings on Derivatives	(55)	12	6
Commodity Derivative Contracts [Member] | Discontinued Operations, Held-for-sale or Disposed of by Sale [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Gain) or Loss Recognized in Earnings on Derivatives	0	0	(1)
Deferred Compensation Derivative Contracts [Member] | General and Administrative Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Gain) or Loss Recognized in Earnings on Derivatives	(8)	(2)	(2)
Treasury Lock [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Gain) or Loss Recognized in Earnings on Derivatives	$ 0	$ (3)	$ 0