Accumulated Other Comprehensive Income (Loss) (Schecule of amounts reclassified from AOCI) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 31, 2021	Jan. 26, 2020	Jan. 31, 2021	Jan. 26, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other expenses / (income)	$ (45)	$ (22)	$ (63)	$ 34
Cost of products sold	1,496	1,420	3,023	2,865
Earnings (loss) from discontinued operations	0	(1,037)	0	(1,034)
Interest expense	55	149	110	229
Taxes on earnings	102	33	199	101
Net Income (Loss) Attributable to Parent	245	1,208	554	1,374
Accumulated Translation Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other expenses / (income)	0	0	0	23
Earnings (loss) from discontinued operations	0	124	0	183
Earnings before taxes	0	124	0	206
Taxes on earnings	0	4	0	4
Net Income (Loss) Attributable to Parent	0	(128)	0	(210)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Earnings before taxes	3	(1)	3	1
Taxes on earnings	0	0	0	(1)
Net Income (Loss) Attributable to Parent	(3)	1	(3)	0
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Foreign Exchange Contract [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of products sold	2	(1)	2	(1)
Earnings (loss) from discontinued operations	0	0	0	1
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Interest Rate Contract [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest expense	1	0	1	1
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other expenses / (income)	(1)	(7)	(2)	(14)
Taxes on earnings	0	2	0	3
Net Income (Loss) Attributable to Parent	$ 1	$ 5	$ 2	$ 11