Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 28, 2019	Apr. 29, 2018	Apr. 28, 2019	Apr. 29, 2018
Statement of Comprehensive Income [Abstract]
Net earnings (loss)	$ 84	$ (393)	$ 219	$ 167
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax [Abstract]
Foreign currency translation adjustments, before tax	(26)	(59)	(49)	(25)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax [Abstract]
Unrealized gains (losses) arising during period, before Tax	2	11	1	22
Reclassification adjustment for (gains) losses included in net earnings, before tax	(1)	1	0	2
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, [Abstract]
Prior service credit arising during the period	0	1	0	(2)
Reclassification of prior service credit included in net earnings, before tax	(8)	(7)	(22)	(20)
Other comprehensive income (loss), before tax	(33)	(53)	(70)	(23)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax [Abstract]
Foreign currency translation adjustments, tax (expense) benefit	0	0	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	0	(3)	0	(7)
Reclassification adjustment for (gains) losses included in net earnings, tax (expense) benefit	0	0	0	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax [Abstract]
Prior service credit arising during the period, tax (expense) benefit	0	(1)	0	0
Reclassification of prior service credit included in net earnings, tax (expense) benefit	2	2	5	6
Other comprehensive income (loss), tax (expense) benefit	2	(2)	5	(1)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Foreign currency translation adjustments, after-tax	(26)	(59)	(49)	(25)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract]
Unrealized gains (losses) arising during the period, after-tax	2	8	1	15
Reclassification adjustment for (gains) losses included in net earnings, after-tax	(1)	1	0	2
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax [Abstract]
Prior service credit arising during the period, after-tax	0	0	0	2
Reclassification of prior service credit included in net earnings, after-tax	(6)	(5)	(17)	(14)
Other comprehensive income (loss), after tax	(31)	(55)	(65)	(24)
Total comprehensive income (loss), after-tax	53	(448)	154	143
Total comprehensive income (loss) attributable to noncontrolling interests	0	0	0	(1)
Total comprehensive income (loss) attributable to Campbell Soup Company	$ 53	$ (448)	$ 154	$ 144