Derivative Instruments (Effect Of Derivative Instruments Not Designated As Hedges On Consolidated Statement Of Operations Summary) (Details) (Derivatives not designated as hedging instruments:, USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 25, 2014	Oct. 26, 2013
Derivative Instruments, Gain (Loss) [Line Items]
GAINS (LOSSES) FOR THE THREE MONTHS ENDED	$ (75)	$ 71
Foreign currency derivatives | Other income (loss), net
Derivative Instruments, Gain (Loss) [Line Items]
GAINS (LOSSES) FOR THE THREE MONTHS ENDED	(58)	43
Total return swaps—deferred compensation | Operating expenses
Derivative Instruments, Gain (Loss) [Line Items]
GAINS (LOSSES) FOR THE THREE MONTHS ENDED	(13)	17
Equity derivatives | Other income (loss), net
Derivative Instruments, Gain (Loss) [Line Items]
GAINS (LOSSES) FOR THE THREE MONTHS ENDED	$ (4)	$ 11