Fair Value Measurements Fair Value Measurements Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jan. 28, 2018	Jan. 28, 2018	Jan. 29, 2017	Jul. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Impairment Loss		$ 75
Cash and Cash Equivalents, at Carrying Value	$ 16	16		$ 8
Long-term Debt	2,486	2,486		2,499
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	16	16		8
Long-term Debt, Fair Value	2,516	2,516		$ 2,582
Campbell Fresh [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Impairment Loss		75
Campbell Fresh [Member] | Bolthouse Farms carrot and carrot ingredients reporting unit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Impairment Loss	$ 75	$ 75	$ 212