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		6 Months Ended
	Jan. 24, 2015	Jan. 25, 2014	Jan. 24, 2015	Jan. 25, 2014
Derivative Instruments, Gain (Loss) [Line Items]
GAINS (LOSSES) FOR THE THREE MONTHS ENDED	$ (30)	$ (38)	$ (105)	$ 33
Foreign currency derivatives | Other income (loss), net
Derivative Instruments, Gain (Loss) [Line Items]
GAINS (LOSSES) FOR THE THREE MONTHS ENDED	(51)	(63)	(109)	(20)
Total return swaps—deferred compensation | Operating expenses
Derivative Instruments, Gain (Loss) [Line Items]
GAINS (LOSSES) FOR THE THREE MONTHS ENDED	13	12	0	29
Equity derivatives | Other income (loss), net
Derivative Instruments, Gain (Loss) [Line Items]
GAINS (LOSSES) FOR THE THREE MONTHS ENDED	$ 8	$ 13	$ 4	$ 24