Derivative Instruments (Additional Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 25, 2015	Jul. 26, 2014
Derivative [Line Items]
Net derivative Gains/losses to be reclassified from AOCI into earnings in next twelve months	$ 5
Types of Items Hedged by Interest Rate Derivatives	In fiscal 2015 and 2014, the Company entered into interest rate swaps designated as fair value hedges related to fixed-rate senior notes that are due on various dates from 2017 through 2025. In the periods prior to fiscal 2013, the Company entered into interest rate swaps designated as fair value hedges related to fixed-rate senior notes that are due in 2016 and 2017.
Net liability position	$ 12	$ 67
Fixed Income Securities [Member]
Derivative [Line Items]
Interest Rate Derivatives Related to Fixed Income Securities	$ 0	0
Cash Flow Hedges
Derivative [Line Items]
Foreign currency cash flow hedges maturity period, maximum, months	18 months
Net investment hedging instruments
Derivative [Line Items]
Foreign currency cash flow hedges maturity period, maximum, months	6 months
Net liability position subject to collateral request
Derivative [Line Items]
Net liability position	$ 0	$ 3