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 $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 26, 2014	Apr. 27, 2013	Apr. 26, 2014	Apr. 27, 2013
Cash Flow Hedging
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)	$ 13	$ (11)	$ 47	$ 58
Gains (losses) reclassified from AOCI into income (effective portion)	16	4	44	7
Cash Flow Hedging | Foreign Currency Derivatives
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)	13	(11)	47	58
Cash Flow Hedging | Foreign Currency Derivatives | Operating Expenses
Derivative [Line Items]
Gains (losses) reclassified from AOCI into income (effective portion)	13	3	36	5
Cash Flow Hedging | Foreign Currency Derivatives | Cost Of Sales-Service
Derivative [Line Items]
Gains (losses) reclassified from AOCI into income (effective portion)	3	1	8	2
Net Investment Hedging
Derivative [Line Items]
Gains (losses) recognized in OCI on derivatives (effective portion)	(10)	20	(13)	(4)
Net Investment Hedging | Other income (loss), net
Derivative [Line Items]
Gains (losses) reclassified from AOCI into income (effective portion)	$ 0	$ 0	$ 0	$ 0