Derivative Instruments (Effect Of Derivative Instruments Designated As Cash Flow Hedges On Other Comprehensive Income And Consolidated Statements Of Operations Summary) (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 30, 2016	Jul. 25, 2015	Jul. 26, 2014
Cash Flow Hedges
Derivative [Line Items]
GAINS (LOSSES) RECOGNIZED IN OCI ON DERIVATIVES FOR THE YEARS ENDED (EFFECTIVE PORTION)	$ (66)	$ (159)	$ 48
GAINS (LOSSES) RECLASSIFIED FROM AOCI INTO INCOME FOR THE YEARS ENDED (EFFECTIVE PORTION)	(20)	(154)	68
Cash Flow Hedges | Foreign currency derivatives
Derivative [Line Items]
GAINS (LOSSES) RECOGNIZED IN OCI ON DERIVATIVES FOR THE YEARS ENDED (EFFECTIVE PORTION)	(66)	(159)	48
Cash Flow Hedges | Foreign currency derivatives | Operating expenses
Derivative [Line Items]
GAINS (LOSSES) RECLASSIFIED FROM AOCI INTO INCOME FOR THE YEARS ENDED (EFFECTIVE PORTION)	(15)	(121)	55
Cash Flow Hedges | Foreign currency derivatives | Cost of sales—service
Derivative [Line Items]
GAINS (LOSSES) RECLASSIFIED FROM AOCI INTO INCOME FOR THE YEARS ENDED (EFFECTIVE PORTION)	(5)	(33)	13
Derivatives designated as net investment hedging instruments: | Foreign currency derivatives
Derivative [Line Items]
GAINS (LOSSES) RECOGNIZED IN OCI ON DERIVATIVES FOR THE YEARS ENDED (EFFECTIVE PORTION)	16	42	(15)
Derivatives designated as net investment hedging instruments: | Foreign currency derivatives | Other income (loss), net
Derivative [Line Items]
GAINS (LOSSES) RECLASSIFIED FROM AOCI INTO INCOME FOR THE YEARS ENDED (EFFECTIVE PORTION)	$ 0	$ 0	$ 0