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 - Interest rate derivatives - Interest expense - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 28, 2017	Jan. 23, 2016	Jan. 28, 2017	Jan. 23, 2016
Hedge Underlying Gain Loss [Line Items]
GAINS (LOSSES) ON DERIVATIVE INSTRUMENTS FOR THE THREE MONTHS ENDED	$ (175)	$ (16)	$ (266)	$ 111
GAINS (LOSSES) RELATED TO HEDGED ITEMS FOR THE THREE MONTHS ENDED	$ 172	$ 18	$ 262	$ (107)