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 |