Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Oct. 27, 2019	Oct. 28, 2018
Statement of Comprehensive Income [Abstract]
Net earnings	$ 166	$ 194
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax [Abstract]
Foreign currency translation adjustments, before tax	(4)	(43)
Reclassification of currency translation adjustments realized upon disposal of business, before tax	82	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax [Abstract]
Reclassification adjustment for (gains) losses included in net earnings, before tax	2	1
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, [Abstract]
Reclassification of prior service credit included in net earnings, before tax	(7)	(7)
Other comprehensive income (loss), before tax	73	(49)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax [Abstract]
Foreign currency translation adjustments, tax (expense) benefit	0	0
Reclassification of currency translation adjustments realized upon disposal of business, tax (expense) benefit	0	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax [Abstract]
Reclassification adjustment for (gains) losses included in net earnings, tax (expense) benefit	(1)	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax [Abstract]
Reclassification of prior service credit included in net earnings, tax (expense) benefit	1	2
Other comprehensive income (loss), tax (expense) benefit	0	2
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Foreign currency translation adjustments, after-tax	(4)	(43)
Reclassification of currency translation adjustments realized upon disposal of business, after-tax	(82)	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract]
Reclassification adjustment for (gains) losses included in net earnings, after-tax	1	1
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax [Abstract]
Reclassification of prior service credit included in net earnings, after-tax	(6)	(5)
Other comprehensive income (loss), after tax	73	(47)
Total comprehensive income (loss), after-tax	239	147
Total comprehensive income (loss) attributable to noncontrolling interests	1	0
Total comprehensive income (loss) attributable to Campbell Soup Company	$ 238	$ 147