Derivative Instruments (Effect Of Derivative Instruments Designated As Fair Value Hedges And Underlying Hedged Items On Consolidated Statements Of Operations Summary) (Details) (Derivatives Designated As Fair Value Hedging Instruments, USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 26, 2014	Apr. 27, 2013	Apr. 26, 2014	Apr. 27, 2013
Hedge Underlying Gain Loss [Line Items]
Gains (losses) on derivative instruments	$ 0	$ (56)	$ (82)	$ (127)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	0	56	81	127
Equity Derivatives | Other income (loss), net
Hedge Underlying Gain Loss [Line Items]
Gains (losses) on derivative instruments	(8)	(45)	(55)	(87)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	8	45	55	87
Interest Rate Derivatives | Interest Expense
Hedge Underlying Gain Loss [Line Items]
Gains (losses) on derivative instruments	8	(11)	(27)	(40)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	$ (8)	$ 11	$ 26	$ 40