Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) (Schecule of amounts reclassified from AOCI) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Aug. 02, 2020	Apr. 26, 2020	Jan. 26, 2020	Oct. 27, 2019	Jul. 28, 2019	Apr. 28, 2019	Jan. 27, 2019	Oct. 28, 2018	Aug. 02, 2020	Jul. 28, 2019	Jul. 29, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other expenses / (income)									$ 221	$ 140	$ (73)
Earnings (loss) from discontinued operations	$ 0	$ 2	$ 1,037	$ (3)	$ (3)	$ (39)	$ (235)	$ 14	1,036	(263)	(463)
Cost of products sold									5,692	5,414	4,241
Interest expense									345	356	183
Taxes on earnings									174	151	106
Net earnings attributable to Campbell Soup Company	$ (86)	$ (168)	$ (1,208)	$ (166)	$ 8	$ (84)	$ 59	$ (194)	(1,628)	(211)	(261)
Accumulated Translation Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other expenses / (income)									23	0	0
Earnings (loss) from discontinued operations									(183)	(2)	0
Earnings before taxes									206	2	0
Taxes on earnings									4	0	0
Net earnings attributable to Campbell Soup Company									210	2	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									0	0	3
Taxes on earnings									0	0	(1)
Net earnings attributable to Campbell Soup Company									0	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]
Earnings (loss) from discontinued operations									(1)	(2)	4
Cost of products sold									(2)	(4)	5
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	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)									(28)	(28)	(27)
Taxes on earnings									6	7	7
Net earnings attributable to Campbell Soup Company									$ (22)	$ (21)	$ (20)