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	3 Months Ended		6 Months Ended
	Jan. 26, 2019	Jan. 27, 2018	Jan. 26, 2019	Jan. 27, 2018
Hedge Underlying Gain Loss [Line Items]
GAINS (LOSSES) ON DERIVATIVE INSTRUMENTS	$ 64	$ (98)	$ 55	$ (158)
GAINS (LOSSES) RELATED TO HEDGED ITEMS	(61)	98	(52)	158
Interest rate derivatives | Interest expense
Hedge Underlying Gain Loss [Line Items]
GAINS (LOSSES) ON DERIVATIVE INSTRUMENTS	64	(63)	55	(109)
GAINS (LOSSES) RELATED TO HEDGED ITEMS	(61)	63	(52)	109
Equity derivatives | Other income (loss), net
Hedge Underlying Gain Loss [Line Items]
GAINS (LOSSES) ON DERIVATIVE INSTRUMENTS	0	(35)	0	(49)
GAINS (LOSSES) RELATED TO HEDGED ITEMS	$ 0	$ 35	$ 0	$ 49