Fair Value Measurements Fair Value Measurements Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jan. 28, 2018	Apr. 29, 2018	Apr. 30, 2017	Jul. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Impairment Loss		$ 540
Cash and Cash Equivalents, at Carrying Value		19		$ 8
Long-term Debt		8,593		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		19		8
Long-term Debt, Fair Value		8,490		$ 2,582
Campbell Fresh [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Impairment Loss		$ 540
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		$ 212