Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) (Schecule of amounts reclassified from AOCI) (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 28, 2018	Oct. 29, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of products sold	$ 1,870	$ 1,378
Interest expense	94	31
Other expenses / (income)	4	(29)
Earnings before taxes	(257)	(382)
Taxes on earnings	63	107
Net earnings attributable to Campbell Soup Company	(194)	(275)
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	(2)
Taxes on earnings	0	0
Net earnings attributable to Campbell Soup Company	1	(2)
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	0	(2)
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
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)
Accumulated Defined Benefit Plans Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Taxes on earnings	2	2
Net earnings attributable to Campbell Soup Company	$ (5)	$ (5)