Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) (Schecule of amounts reclassified from AOCI) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 28, 2019	Apr. 29, 2018	Apr. 28, 2019	Apr. 29, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of products sold	$ 1,455	$ 1,263	$ 4,781	$ 3,624
Interest expense	92	44	279	107
Other expenses / (income)	20	35	13	(7)
Earnings (loss) before taxes	(175)	(116)	(734)	(796)
Taxes on earnings	44	43	184	106
Net earnings (loss) attributable to Campbell Soup Company	(84)	393	(219)	(167)
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)	1	0	2
Taxes on earnings	0	0	0	0
Net earnings (loss) attributable to Campbell Soup Company	(1)	1	0	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	(1)	0	(1)	0
Other Operating Income (Expense), Net	(1)	0	(1)	0
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	2
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)	(8)	(7)	(22)	(20)
Taxes on earnings	2	2	5	6
Net earnings (loss) attributable to Campbell Soup Company	$ (6)	$ (5)	$ (17)	$ (14)