Derivative Instruments (Effect Of Derivative Instruments Not Designated As Hedges On Consolidated Statement Of Operations Summary) (Detail) (Derivatives Not Designated As Hedging Instruments, USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 27, 2013	Jul. 28, 2012	Jul. 30, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in income	$ (13)	$ (193)	$ 322
Foreign Currency Derivatives | Other income (loss), net
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in income	(74)	(206)	264
Total Return Swap [Member] | Cost of sales - product
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in income	0	4	0
Total Return Swap [Member] | Operating expenses
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in income	61	3	33
Equity Derivatives | Other income (loss), net
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in income	$ 0	$ 6	$ 25