Accumulated Other Comprehensive Income (Loss) (Schecule of amounts reclassified from AOCI) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 29, 2018	Apr. 30, 2017	Apr. 29, 2018	Apr. 30, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of products sold	$ 1,507	$ 1,188	$ 4,299	$ 3,899
Interest expense	44	29	107	87
Other expenses / (income)	647	(15)	688	197
Earnings (loss) before taxes	517	(270)	(76)	(876)
Taxes on earnings	(124)	94	(91)	307
Net earnings (loss) attributable to Campbell Soup Company	393	(176)	(167)	(569)
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 (loss) before taxes	1	2	2	9
Taxes on earnings	0	(1)	0	(3)
Net earnings (loss) attributable to Campbell Soup Company	1	1	2	6
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	1	0	5
Other Operating Income (Expense), Net	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	1	2	3
Accumulated Defined Benefit Plans Adjustment, Net Prior Service [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other expenses / (income)	(7)	(5)	(20)	(18)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Taxes on earnings	2	1	6	6
Net earnings (loss) attributable to Campbell Soup Company	$ (5)	$ (4)	$ (14)	$ (12)