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. 27, 2013	Jul. 28, 2012	Jul. 30, 2011
Cash Flow Hedging
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)	$ 73	$ (131)	$ 87
Gains (losses) reclassified from AOCI into income (effective portion)	12	(72)	108
Cash Flow Hedging | Cost Of Sales-Service
Derivative [Line Items]
Gains (losses) reclassified from AOCI into income (effective portion)	2	(14)	17
Cash Flow Hedging | Foreign Currency Derivatives
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)	73	(131)	87
Cash Flow Hedging | Foreign Currency Derivatives | Operating Expenses
Derivative [Line Items]
Gains (losses) reclassified from AOCI into income (effective portion)	10	(59)	89
Cash Flow Hedging | Interest Rate Derivatives
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)	0	0	0
Cash Flow Hedging | Interest Rate Derivatives | Interest Expense
Derivative [Line Items]
Gains (losses) reclassified from AOCI into income (effective portion)	0	1	2
Net Investment Hedging | Foreign Currency Derivatives
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)	(1)	23	(10)
Gains (losses) reclassified from AOCI into income (effective portion)	$ 0	$ 0	$ 0