Fair Value Measurements Fair Value Measurements Narrative (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Jul. 28, 2019	Jul. 30, 2017	Jul. 28, 2019	Jul. 29, 2018	Jul. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Impairment Charges		$ 12	$ 393	$ 748	$ 212
Debt, Long-term and Short-term, Combined Amount	$ 8,474		8,474	9,516
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt, Long-term and Short-term, Combined Fair Value	8,642		8,642	9,268
Kelsen [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Disposal Group, Including Discontinued Operation, Other Expense	10
Discontinued Operations, Held-for-sale or Disposed of by Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	19		19	14
Cash and Cash Equivalents, at Carrying Value	19		19	14
Debt, Long-term and Short-term, Combined Amount	238		238	378
Discontinued Operations, Held-for-sale or Disposed of by Sale [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt, Long-term and Short-term, Combined Fair Value	238		$ 238	$ 378
Trademarks [Member] | Kelsen [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Disposal Group, Including Discontinued Operation, Other Expense	7
Customer Relationships [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of Intangible Assets, Finite-lived	$ 16