Fair Value (Fair Value On Nonrecurring Basis) (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 30, 2016	Jul. 25, 2015	Jul. 26, 2014
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Losses for assets measured on a nonrecurring basis	$ (141)	$ (221)	$ (23)
Investments In Privately Held Companies | Other Nonoperating Income (Expense) [Member]
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Losses for assets measured on a nonrecurring basis	(57)	(38)	(21)
Purchased Intangible Assets [Member] | Cost of Sales and Operating Expenses [Member]
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Losses for assets measured on a nonrecurring basis	(74)	(175)	0
Assets No Longer Held At Period End | General and administrative
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Losses for assets measured on a nonrecurring basis	$ (10)	$ (8)	$ (2)