Financial Instruments (Schedule Of Changes In Cash Flow Hedges In Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 31, 2021	Jan. 26, 2020	Jan. 31, 2021	Jan. 26, 2020
Derivative Instruments, Gain (Loss) [Line Items]
OCI before tax accumulated derivative gain (loss) beginning of period	$ (9)	$ (9)	$ (8)	$ (11)
OCI before tax accumulated derivative gain (loss) end of period	(12)	(9)	(12)	(9)
Foreign Exchange Forward
Derivative Instruments, Gain (Loss) [Line Items]
OCI, before Reclassifications, before Tax, Attributable to Parent	(6)	1	(7)	1
Foreign Exchange Forward | Cost Of Products Sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	2	(1)	2	(1)
Foreign Exchange Forward | Loss from discontinued operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax			0	1
Interest Rate Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	$ 1	$ 0	$ 1	$ 1