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. 29, 2018	Apr. 29, 2018	Jan. 28, 2018	Oct. 29, 2017	Jul. 30, 2017	Apr. 30, 2017	Jan. 29, 2017	Oct. 30, 2016	Jul. 29, 2018	Jul. 30, 2017	Jul. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of products sold									$ 5,869	$ 4,965	$ 5,033
Interest expense									201	112	115
Other expenses / (income)									619	(9)	405
Earnings before taxes									(272)	(1,293)	(849)
Taxes on earnings									11	406	286
Net earnings attributable to Campbell Soup Company	$ (94)	$ 393	$ (285)	$ (275)	$ (318)	$ (176)	$ (101)	$ (292)	(261)	(887)	(563)
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									3	11	(9)
Taxes on earnings									(1)	(4)	2
Net earnings attributable to Campbell Soup Company									2	7	(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									1	6	(11)
Other operating income / (expenses)									0	1	(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									2	4	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)									(27)	(25)	(1)
Accumulated Defined Benefit Plans Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Taxes on earnings									7	9	0
Net earnings attributable to Campbell Soup Company									$ (20)	$ (16)	$ (1)