Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Oct. 28, 2018	Oct. 29, 2017
Statement of Comprehensive Income [Abstract]
Net earnings	$ 194	$ 275
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax [Abstract]
Foreign currency translation adjustments, before tax	(43)	(32)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax [Abstract]
Unrealized gains (losses) arising during period, before Tax	0	9
Reclassification adjustment for (gains) losses included in net earnings, before tax	1	(2)
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	(49)	(32)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax [Abstract]
Foreign currency translation adjustments, tax (expense) benefit	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	(2)
Reclassification adjustment for (gains) losses included in net earnings, tax (expense) benefit	0	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	2	2
Other comprehensive income (loss), tax (expense) benefit	2	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Foreign currency translation adjustments, after-tax	(43)	(32)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract]
Unrealized gains (losses) arising during the period, after-tax	0	7
Reclassification adjustment for (gains) losses included in net earnings, after-tax	1	(2)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax [Abstract]
Reclassification of prior service credit included in net earnings, after-tax	(5)	(5)
Other comprehensive income (loss), after tax	(47)	(32)
Total comprehensive income (loss), after-tax	147	243
Total comprehensive income (loss) attributable to noncontrolling interests	0	0
Total comprehensive income (loss) attributable to Campbell Soup Company	$ 147	$ 243