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		9 Months Ended
	Apr. 27, 2019	Apr. 28, 2018	Apr. 27, 2019	Apr. 28, 2018
Hedge Underlying Gain Loss [Line Items]
GAINS (LOSSES) ON DERIVATIVE INSTRUMENTS	$ 33	$ (34)	$ 88	$ (192)
GAINS (LOSSES) RELATED TO HEDGED ITEMS	(31)	33	(83)	191
Interest rate derivatives | Interest expense
Hedge Underlying Gain Loss [Line Items]
GAINS (LOSSES) ON DERIVATIVE INSTRUMENTS	33	(59)	88	(168)
GAINS (LOSSES) RELATED TO HEDGED ITEMS	(31)	58	(83)	167
Equity derivatives | Other income (loss), net
Hedge Underlying Gain Loss [Line Items]
GAINS (LOSSES) ON DERIVATIVE INSTRUMENTS	0	25	0	(24)
GAINS (LOSSES) RELATED TO HEDGED ITEMS	$ 0	$ (25)	$ 0	$ 24