Recent Accounting Pronouncements Schedule of Changes (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended								12 Months Ended
		Jul. 28, 2019	Apr. 28, 2019	Jan. 27, 2019	Oct. 28, 2018	Jul. 29, 2018	Apr. 29, 2018	Jan. 28, 2018	Oct. 29, 2017	Jul. 28, 2019		Jul. 29, 2018	Jul. 30, 2017	Jul. 31, 2016
Accrued liabilities		$ 609				$ 516				$ 609		$ 516
Accrued income taxes		15				10				15		10
Total current liabilities		3,385				3,594				3,385		3,594
Total liabilities		12,036				13,156				12,036		13,156
Earnings retained in the business		1,993				2,224				1,993		2,224
Total Campbell Soup Company shareholders' equity		1,103				1,364				1,103		1,364
Total Equity		1,112				1,373				1,112		1,373	$ 1,645	$ 1,533
Net sales		$ 1,780	$ 1,953	$ 2,172	$ 2,202	$ 1,745	$ 1,618	$ 1,614	$ 1,638	8,107		6,615	5,837
Cost of products sold										5,414		4,241	3,395
Total costs and expenses										7,128		5,605	4,406
Earnings before interest and taxes										979		1,010	1,431
Earnings before taxes										625		830	1,316
Taxes on earnings										151		$ 106	$ 392
Earnings from continuing operations attributable to parent										$ 474
Earnings from continuing operations attributable to Campbell Soup Company		$ (0.02)	$ 0.41	$ 0.58	$ 0.60	$ 0.42	$ 0.19	$ 1.04	$ 0.75	$ 1.57	[1]	$ 2.41	$ 3.03
Earnings from continuing operations attributable to Campbell Soup Company		$ (0.02)	$ 0.41	$ 0.58	$ 0.60	$ 0.42	$ 0.19	$ 1.04	$ 0.75	$ 1.57		$ 2.40	$ 3.01
Marketing and selling expenses										$ 842		$ 728	$ 675
Administrative expenses										610		563	448
Research and development expenses										91		91	93
Other Nonoperating Income (Expense)										140		$ (73)	(216)
Balances without adoption of Topic 606
Accrued liabilities		$ 605								605
Accrued income taxes		16								16
Total current liabilities		3,382								3,382
Total liabilities		12,033								12,033
Earnings retained in the business		1,996								1,996
Total Campbell Soup Company shareholders' equity		1,106								1,106
Total Equity		1,115								1,115
Net sales										8,099
Cost of products sold										5,413
Total costs and expenses										7,127
Earnings before interest and taxes										972
Earnings before taxes										618
Taxes on earnings										149
Earnings from continuing operations attributable to parent										$ 469
Earnings from continuing operations attributable to Campbell Soup Company	[1]									$ 1.56
Earnings from continuing operations attributable to Campbell Soup Company										$ 1.55
Adjustments due to adoption of Topic 606
Accrued liabilities		4								$ 4
Accrued income taxes		(1)								(1)
Total current liabilities		3								3
Total liabilities		3								3
Earnings retained in the business		(3)								(3)
Total Campbell Soup Company shareholders' equity		(3)								(3)
Total Equity		$ (3)								(3)
Net sales										8
Cost of products sold										1
Total costs and expenses										1
Earnings before interest and taxes										7
Earnings before taxes										7
Taxes on earnings										2
Earnings from continuing operations attributable to parent										$ 5
Earnings from continuing operations attributable to Campbell Soup Company	[1]									$ 0.02
Earnings from continuing operations attributable to Campbell Soup Company										$ 0.02
Accounting Standards Update 2017-07 [Member]
Cost of products sold													134
Marketing and selling expenses													38
Administrative expenses													62
Research and development expenses													13
Other Nonoperating Income (Expense)													$ (247)

[1] The sum of individual per share amounts may not add due to rounding.