Derivative Instruments (Additional Information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			3 Months Ended
	Oct. 26, 2013	Oct. 26, 2013 Fixed Income Securities [Member]	Jul. 27, 2013 Fixed Income Securities [Member]	Oct. 26, 2013 Senior Notes [Member]	Oct. 26, 2013 Cash Flow Hedging [Member] Foreign Exchange Contract	Oct. 26, 2013 Net Investment Hedging [Member]
Derivative [Line Items]
Number of Interest Rate Derivatives Held		0	0
Net derivative gains to be reclassified from AOCI into earnings in next twelve months	$ 49
Foreign currency cash flow hedges maturity period, maximum (in months)					0 years 18 months 0 days	0 years 6 months 0 days
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.