Derivative Instruments (Effect Of Derivative Instruments Designated As Fair Value Hedges And Underlying Hedged Items On Consolidated Statements Of Operations) (Details) - Derivatives Designated as Fair Value Hedging Instruments - USD ($) $ in Millions	12 Months Ended
	Jul. 29, 2017	Jul. 30, 2016	Jul. 25, 2015
Hedge Underlying Gain Loss [Line Items]
GAINS (LOSSES) ON DERIVATIVE INSTRUMENTS FOR THE YEARS ENDED	$ (275)	$ 175	$ 110
GAINS (LOSSES) RELATED TO HEDGED ITEMS FOR THE YEARS ENDED	271	(169)	(113)
Equity derivatives | Other income (loss), net
Hedge Underlying Gain Loss [Line Items]
GAINS (LOSSES) ON DERIVATIVE INSTRUMENTS FOR THE YEARS ENDED	0	0	56
GAINS (LOSSES) RELATED TO HEDGED ITEMS FOR THE YEARS ENDED	0	0	(56)
Interest rate derivatives | Interest expense
Hedge Underlying Gain Loss [Line Items]
GAINS (LOSSES) ON DERIVATIVE INSTRUMENTS FOR THE YEARS ENDED	(275)	175	54
GAINS (LOSSES) RELATED TO HEDGED ITEMS FOR THE YEARS ENDED	$ 271	$ (169)	$ (57)