Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 29, 2018	Apr. 30, 2017	Apr. 29, 2018	Apr. 30, 2017
Statement of Comprehensive Income [Abstract]
Net earnings (loss)	$ (393)	$ 176	$ 167	$ 569
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax [Abstract]
Foreign currency translation adjustments, before tax	(59)	(4)	(25)	(28)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax [Abstract]
Unrealized gains (losses) arising during the period, before Tax	11	2	22	32
Reclassification adjustment for (gains) losses included in net earnings, before tax	1	2	2	9
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, [Abstract]
Prior service cost arising during the period, before Tax	1	0	(2)	0
Reclassification of prior service credit included in net earnings, before tax	(7)	(5)	(20)	(18)
Other comprehensive income (loss), before tax	(53)	(5)	(23)	(5)
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), Derivatives Qualifying as Hedges, Tax Effect [Abstract]
Unrealized gains (losses) arising during the period, tax (expense) benefit	(3)	0	(7)	(11)
Reclassification adjustment for (gains) losses included in net earnings, tax (expense) benefit	0	(1)	0	(3)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax [Abstract]
Prior service cost arising during the period, Tax	(1)	0	0	0
Reclassification of prior service credit included in net earnings, tax (expense) benefit	2	1	6	6
Other comprehensive income (loss), tax (expense) benefit	(2)	0	(1)	(8)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Foreign currency translation adjustments, after-tax	(59)	(4)	(25)	(28)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
Unrealized gains (losses) arising during the period, after-tax	8	2	15	21
Reclassification adjustment for (gains) losses included in net earnings, after-tax	1	1	2	6
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax [Abstract]
Prior service cost arising during the period, after Tax	0	0	(2)	0
Reclassification of prior service credit included in net earnings, after-tax	(5)	(4)	(14)	(12)
Other comprehensive income (loss), after tax	(55)	(5)	(24)	(13)
Total comprehensive income (loss), after-tax	(448)	171	143	556
Total comprehensive income (loss) attributable to noncontrolling interests	0	0	(1)	1
Total comprehensive income (loss) attributable to Campbell Soup Company	$ (448)	$ 171	$ 144	$ 555