Quarterly Data (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
Net sales	$ 1,780		$ 1,953		$ 2,172		$ 2,202		$ 1,745		$ 1,618		$ 1,614		$ 1,638		$ 8,107		$ 6,615		$ 5,837
Gross profit	606		655		706		726		548		533		637		656
Earnings (loss) from continuing operations	(5)		123		176		180		126		57		314		227
Earnings (loss) from discontinued operations	(3)		(39)		(235)		14		(32)		(450)		(29)		48		(263)		(463)		(37)
Net earnings (loss) attributable to Campbell Soup Company	$ (8)		$ 84		$ (59)		$ 194		$ 94		$ (393)		$ 285		$ 275		$ 211		$ 261		$ 887
Earnings (loss) from continuing operations attributable to Campbell Soup Company per share, basic	$ (0.02)		$ 0.41		$ 0.58		$ 0.60		$ 0.42		$ 0.19		$ 1.04		$ 0.75		$ 1.57	[1]	$ 2.41		$ 3.03
Earnings (loss) from discontinued operations per share, basic	(0.01)		(0.13)		(0.78)		0.05		(0.11)		(1.50)		(0.10)		0.16		(0.87)		(1.54)		(0.12)
Earnings (loss) per share, basic	(0.03)	[2]	0.28	[2]	(0.20)	[2]	0.64	[2]	0.31	[2]	(1.31)	[2]	0.95	[2]	0.91	[2]	0.70		0.87		2.91
Common Stock, Dividends, Per Share, Declared	0.35		0.35		0.35		0.35		0.35		0.35		0.35		0.35		1.40		1.40		1.40
Earnings (loss) from continuing operations attributable to Campbell Soup Company Per Share, Diluted	(0.02)		0.41		0.58		0.60		0.42		0.19		1.04		0.75		1.57		2.40		3.01
Earnings (loss) from discontinued operations Per Share, Diluted	(0.01)		(0.13)		(0.78)		0.05		(0.11)		(1.50)		(0.10)		0.16		(0.87)		(1.53)		(0.12)
Earnings (loss) Per Share, Diluted	$ (0.03)	[2]	$ 0.28	[2]	$ (0.20)	[2]	$ 0.64	[2]	$ 0.31	[2]	$ (1.31)	[2]	$ 0.95	[2]	$ 0.91	[2]	$ 0.70	[3]	$ 0.86	[3]	$ 2.89	[3]
Restructuring charges, implementation costs and other related costs, net of tax	$ 24		$ 16		$ 18		$ 34		$ 34		$ 41		$ 45		$ 12
Asset Impairment Charges, net of tax	13		0		0		0		41		0		0		0
Pension and postretirement benefits mark to market adj, net of tax	93		0		0		0		(90)		0		0		(9)
Charges Related to Pension Settlement, net of tax	0		22		0		0
Tax Cuts and Jobs Act of 2017, Provisional Income Tax Expense (Benefit)	$ 0		$ 0		$ 2		$ 0		(6)		0		(124)		0
Business Combination, Acquisition Related Costs, net of tax									8		46		19		0
Charges Related to Litigation Settlement, net of tax									$ 0		$ 15		$ 0		$ 0
Restructuring charges, Per Diluted Share	$ 0.08		$ 0.05		$ 0.06		$ 0.11		$ 0.11		$ 0.14		$ 0.15		$ 0.04
Asset Impairment Charges, Per Diluted Share	0.04		0.00		0.00		0.00		0.14		0.00		0.00		0.00
Pension and postretirement benefits mark to market adjustment, Per Diluted Share	0.31		(0.00)		(0.00)		(0.00)		(0.30)		(0.00)		(0.00)		(0.03)
Charges Related to a Pension Settlement, Per Diluted Share	0.00		0.07		0.00		0.00
Tax Cuts and Jobs Act of 2017, Provisional Income Tax Expense (Benefit), Per Diluted Share	$ 0.00		$ 0.00		$ 0.01		$ 0.00		(0.02)		0.00		(0.41)		0.00
Business Combination Acquisition Related Costs Per Diluted Share									0.03		0.15		0.06		0.00
Charges Related to Litigation Settlement, Per Diluted Share									$ 0.00		$ 0.05		$ 0.00		$ 0.00
Discontinued Operations, Held-for-sale or Disposed of by Sale [Member]
Restructuring charges, implementation costs and other related costs, net of tax	$ 0		$ (1)		$ 0		$ 1		$ (1)		$ 4		$ 1		$ 0
Asset Impairment Charges, net of tax	12		0		264		11		0		497		74		0
Pension and postretirement benefits mark to market adj, net of tax	9		0		0		0		$ (3)		$ 0		$ 0		$ 0
Costs Associated with Divestitures, net of tax	$ 4		$ 48		$ 8		$ 0
Restructuring charges, Per Diluted Share	$ 0.00		$ 0.00		$ 0.00		$ 0.00		$ 0.00		$ 0.01		$ 0.00		$ 0.00
Asset Impairment Charges, Per Diluted Share	0.04		0.00		0.87		0.04		0.00		1.65		0.25		0.00
Pension and postretirement benefits mark to market adjustment, Per Diluted Share	0.03		(0.00)		(0.00)		(0.00)		$ (0.01)		$ (0.00)		$ (0.00)		$ (0.00)
Costs Associated with Divestitures, Per Diluted Share	$ 0.01		$ 0.16		$ 0.03		$ 0.00

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

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

[3] Sum of the individual amounts may not add due to rounding.