Accumulated Other Comprehensive Income (Loss) (Schecule of amounts reclassified from AOCI) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 28, 2018	Jan. 29, 2017	Jan. 28, 2018	Jan. 29, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of products sold	$ 1,414	$ 1,360	$ 2,792	$ 2,711
Interest expense	32	29	63	58
Other expenses / (income)	70	201	41	212
Earnings before taxes	(211)	(177)	(593)	(606)
Taxes on earnings	(74)	76	33	213
Net earnings attributable to Campbell Soup Company	(285)	(101)	(560)	(393)
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	5	1	7
Taxes on earnings	0	(2)	0	(2)
Net earnings attributable to Campbell Soup Company	3	3	1	5
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	2	3	0	4
Other Operating Income (Expense), Net	0	1	0	1
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	1	2
Accumulated Defined Benefit Plans Adjustment, Net Prior Service [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other expenses / (income)	(6)	(7)	(13)	(13)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Taxes on earnings	2	3	4	5
Net earnings attributable to Campbell Soup Company	$ (4)	$ (4)	$ (9)	$ (8)