Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) (Schecule of amounts reclassified from AOCI) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 27, 2019	Jan. 28, 2018	Jan. 27, 2019	Jan. 28, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of products sold	$ 1,999	$ 1,414	$ 3,869	$ 2,792
Interest expense	93	32	187	63
Other expenses / (income)	226	70	230	41
Earnings (loss) before taxes	73	(211)	(184)	(593)
Taxes on earnings	(14)	(74)	49	33
Net earnings (loss) attributable to Campbell Soup Company	59	(285)	(135)	(560)
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	0	3	1	1
Taxes on earnings	0	0	0	0
Net earnings (loss) attributable to Campbell Soup Company	0	3	1	1
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	2	0	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	0	1	1	1
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)	(7)	(6)	(14)	(13)
Accumulated Defined Benefit Plans Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Taxes on earnings	1	2	3	4
Net earnings (loss) attributable to Campbell Soup Company	$ (6)	$ (4)	$ (11)	$ (9)