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
	Jul. 28, 2019	Apr. 28, 2019	Jan. 27, 2019	Oct. 28, 2018	Jul. 29, 2018	Apr. 29, 2018	Jan. 28, 2018	Oct. 29, 2017	Jul. 28, 2019	Jul. 29, 2018	Jul. 30, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of products sold									$ 5,414	$ 4,241	$ 3,395
Loss from discontinued operations	$ 3	$ 39	$ 235	$ (14)	$ 32	$ 450	$ 29	$ (48)	263	463	37
Interest expense									356	183	115
Other expenses / (income)									140	(73)	(216)
Taxes on earnings									(151)	(106)	(392)
Net earnings attributable to Campbell Soup Company	$ 8	$ (84)	$ 59	$ (194)	$ (94)	$ 393	$ (285)	$ (275)	(211)	(261)	(887)
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	3	11
Taxes on earnings									0	1	4
Net earnings attributable to Campbell Soup Company									0	2	7
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									(4)	5	3
Other operating income / (expenses)									0	0	1
Loss from discontinued operations									2	(4)	3
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									2	2	4
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)	(27)	(25)
Taxes on earnings									7	7	9
Net earnings attributable to Campbell Soup Company									$ (21)	$ (20)	$ (16)