Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Aug. 02, 2020	Jul. 28, 2019	Jul. 29, 2018
Statement of Comprehensive Income [Abstract]
Net earnings	$ 1,628	$ 211	$ 261
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax [Abstract]
Foreign currency translation adjustments, before tax	(1)	(68)	(69)
Reclassification of currency translation adjustments realized upon disposal of business, before tax	206	2	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax [Abstract]
Unrealized gains (losses) arising during period, before Tax	3	(3)	23
Reclassification adjustment for (gains) losses included in net earnings, before tax	0	0	3
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, [Abstract]
Prior service credit arising during the period, before tax	0	0	9
Reclassification of prior service credit included in net earnings, before tax	(28)	(28)	(27)
Other comprehensive income (loss), before tax	180	(97)	(61)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax [Abstract]
Foreign currency translation adjustments, tax (expense) benefit	0	0	0
Reclassification of currency translation adjustments realized upon disposal of business, tax (expense) benefit	4	0	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax [Abstract]
Unrealized gains (losses) arising during the period, tax (expense) benefit	(1)	1	(7)
Reclassification adjustment for (gains) losses included in net earnings, tax (expense) benefit	0	0	(1)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax [Abstract]
Prior service credit arising during the period, tax	0	0	(2)
Reclassification of prior service credit included in net earnings, tax (expense) benefit	6	7	7
Other comprehensive income (loss), tax (expense) benefit	9	8	(3)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Foreign currency translation adjustments, after-tax	(1)	(68)	(69)
Reclassification of currency translation adjustments realized upon disposal of business, after-tax	(210)	(2)	0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract]
Unrealized gains (losses) arising during the period, after-tax	2	(2)	16
Reclassification adjustment for (gains) losses included in net earnings, after-tax	0	0	2
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax [Abstract]
Prior service credit arising during the period, net of tax	0	0	7
Reclassification of prior service credit included in net earnings, after-tax	(22)	(21)	(20)
Other comprehensive income (loss), after tax	189	(89)	(64)
Total comprehensive income (loss), after-tax	1,817	122	197
Total comprehensive income (loss) attributable to noncontrolling interests	1	0	1
Total comprehensive income (loss) attributable to Campbell Soup Company	$ 1,816	$ 122	$ 196