Derivative Instruments (Effect Of Derivative Instruments Designated As Cash Flow Hedges On Other Comprehensive Income And Consolidated Statements Of Operations Summary) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 28, 2012	Jul. 30, 2011	Jul. 31, 2010
Cash Flow Hedging
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)	$ (131)	$ 87	$ 56
Gains (losses) reclassified from AOCI into income (effective portion)	(72)	108	(1)
Cash Flow Hedging | Foreign Currency Derivatives
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)	(131)	87	33
Cash Flow Hedging | Interest Rate Derivatives
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)			23
Cash Flow Hedging | Operating Expenses | Foreign Currency Derivatives
Derivative [Line Items]
Gains (losses) reclassified from AOCI into income (effective portion)	(59)	89	(1)
Cash Flow Hedging | Cost Of Sales-Service
Derivative [Line Items]
Gains (losses) reclassified from AOCI into income (effective portion)	(14)	17
Cash Flow Hedging | Interest Expense | Interest Rate Derivatives
Derivative [Line Items]
Gains (losses) reclassified from AOCI into income (effective portion)	1	2
Net Investment Hedging | Foreign Currency Derivatives
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)	$ 23	$ (10)	$ (2)