Accumulated Other Comprehensive Income (Loss) (Schecule of amounts reclassified from AOCI) (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 27, 2019	Oct. 28, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other expenses / (income)	$ 56	$ 0
Earnings (loss) from discontinued operations	3	(14)
Interest expense	80	91
Taxes on earnings	(68)	(56)
Net earnings attributable to Campbell Soup Company	(166)	(194)
Accumulated Translation Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other expenses / (income)	23	0
Earnings (loss) from discontinued operations	59	0
Earnings before taxes	82	0
Taxes on earnings	0	0
Net earnings attributable to Campbell Soup Company	82	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	2	1
Taxes on earnings	1	0
Net earnings attributable to Campbell Soup Company	1	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]
Earnings (loss) from discontinued operations	1	0
Interest expense	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	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)
Taxes on earnings	1	2
Net earnings attributable to Campbell Soup Company	$ (6)	$ (5)