Derivative Instruments (Effect Of Derivative Instruments Not Designated As Fair Value Hedges On Consolidated Statement Of Operations Summary) (Details) (Derivatives Not Designated As Hedging Instruments [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 27, 2013	Apr. 28, 2012	Apr. 27, 2013	Apr. 28, 2012
Derivative [Line Items]
Gains (losses) recognized in income	$ (84)	$ 34	$ (27)	$ (129)
Foreign Exchange Contract [Member] | Other Income (loss), net [Member]
Derivative [Line Items]
Gains (losses) recognized in income	(90)	20	(78)	(125)
Total Return Swaps-Deferred Compensation [Member] | Cost of Sales [Member]
Derivative [Line Items]
Gains (losses) recognized in income	0	1	0	4
Total Return Swaps-Deferred Compensation [Member] | Operating Expenses [Member]
Derivative [Line Items]
Gains (losses) recognized in income	12	6	45	(4)
Equity Derivatives [Member] | Other Income (loss), net [Member]
Derivative [Line Items]
Gains (losses) recognized in income	$ (6)	$ 7	$ 6	$ (4)