Fair Value (Fair Value On Nonrecurring Basis) (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 25, 2015	Jul. 26, 2014	Jul. 27, 2013
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Losses for assets measured on a nonrecurring basis	$ (221)	$ (23)	$ 43
Investments in privately held companies (impaired) | Other income (loss), net
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Losses for assets measured on a nonrecurring basis	(38)	(21)	(31)
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	(175)	0	0
Property held for sale—land and buildings | General and administrative
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Losses for assets measured on a nonrecurring basis	0	0	(1)
Gains (losses) on assets no longer held at end of fiscal year
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Losses for assets measured on a nonrecurring basis	$ (8)	$ (2)
Gains on assets no longer held			$ 75