Accumulated Other Comprehensive Income (Loss) (Schecule of amounts reclassified from AOCI) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 26, 2020	Jan. 27, 2019	Jan. 26, 2020	Jan. 27, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other expenses / (income)	$ (22)	$ (8)	$ 34	$ (8)
Cost of products sold	1,420	1,466	2,865	2,942
Earnings (loss) from discontinued operations	(1,037)	235	(1,034)	221
Interest expense	149	91	229	182
Taxes on earnings	(33)	(58)	(101)	(114)
Net earnings attributable to Campbell Soup Company	(1,208)	59	(1,374)	(135)
Accumulated Translation Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other expenses / (income)	0	0	23	0
Earnings (loss) from discontinued operations	124	0	183	0
Earnings before taxes	124	0	206	0
Taxes on earnings	(4)	0	(4)	0
Net earnings attributable to Campbell Soup Company	128	0	210	0
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	(1)	0	1	1
Taxes on earnings	0	0	1	0
Net earnings attributable to Campbell Soup Company	(1)	0	0	1
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	(1)	0	(1)	0
Earnings (loss) from discontinued operations	0	0	1	0
Interest expense	0	0	1	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	0	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)	(7)	(7)	(14)	(14)
Taxes on earnings	2	1	3	3
Net earnings attributable to Campbell Soup Company	$ (5)	$ (6)	$ (11)	$ (11)