Fair Value Measurements Fair Value Measurements Narrative (Details) - USD ($) $ in Millions	Oct. 27, 2019	Jul. 28, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt, Long-term and Short-term, Combined Amount	$ 8,337	$ 8,474
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	8,641	8,642
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
Cash and Cash Equivalents, at Carrying Value	19	19
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	$ 7	$ 238