Derivative Instruments (Effect Of Derivative Instruments Designated As Cash Flow Hedges And Net Investment Hedging Instruments On Other Comprehensive And Consolidated Statements Of Operations Summary) (Details) (USD $)	3 Months Ended		9 Months Ended
	Apr. 27, 2013	Apr. 28, 2012	Apr. 27, 2013	Apr. 28, 2012
Interest Expense [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)	$ 0	$ 0	$ 0	$ 0
Gains (losses) reclassified from AOCI into income (effective portion)	0	1,000,000	0	1,000,000
Cash Flow Hedging [Member]
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)	(11,000,000)	11,000,000	58,000,000	(83,000,000)
Gains (losses) reclassified from AOCI into income (effective portion)	4,000,000	(18,000,000)	7,000,000	(44,000,000)
Cash Flow Hedging [Member] | Foreign Currency Derivatives-Cash Flow Hedges [Member]
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)	(11,000,000)	11,000,000	58,000,000	(83,000,000)
Cash Flow Hedging [Member] | Operating Expenses [Member] | Foreign Currency Derivatives-Cash Flow Hedges [Member]
Derivative [Line Items]
Gains (losses) reclassified from AOCI into income (effective portion)	3,000,000	(15,000,000)	5,000,000	(37,000,000)
Cash Flow Hedging [Member] | Cost Of Sales-Service [Member] | Foreign Currency Derivatives-Cash Flow Hedges [Member]
Derivative [Line Items]
Gains (losses) reclassified from AOCI into income (effective portion)	1,000,000	(4,000,000)	2,000,000	(8,000,000)
Net Investment Hedging [Member]
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)	20,000,000	0	(4,000,000)	(6,000,000)
Net Investment Hedging [Member] | Other income (loss), net [Member]
Derivative [Line Items]
Gains (losses) reclassified from AOCI into income (effective portion)	$ 0	$ 0	$ 0	$ 0