Derivative Instruments (Additional Information) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Apr. 26, 2014	Jul. 27, 2013
Derivative [Line Items]
Net derivative gains to be reclassified from AOCI into earnings in next twelve months	$ 22
Derivative Asset, Fair Value	148	182
Fixed Income Securities
Derivative [Line Items]
Number of Interest Rate Derivatives Held	0	0
Senior Notes
Derivative [Line Items]
Description of Interest Rate Derivative Activities	In fiscal 2014 and 2013, the Company entered into interest rate swaps designated as fair value hedges related to fixed-rate senior notes that were issued in February 2009 and November 2009 and are due in 2019 and 2020, respectively. In the previous periods, the Company entered into interest rate swaps designated as fair value hedges related to fixed-rate senior notes that were issued in 2006 and 2011 and are due in 2014, 2016, and 2017.
Cash Flow Hedging | Foreign Currency Derivatives
Derivative [Line Items]
Derivative, Term of Contract	18 months
Net Investment Hedging
Derivative [Line Items]
Derivative, Term of Contract	6 months
Right to request collateral subject to specified credit rating and in net liability position [Member]
Derivative [Line Items]
Derivative Asset, Fair Value	$ 67	$ 88