v3.19.1

Available-for-Sale Debt Investments and Equity Investments (Additional Information) (Details) | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Apr. 27, 2019 USD ($) entity | Apr. 28, 2018 USD ($) | Apr. 27, 2019 USD ($) entity | Apr. 28, 2018 USD ($) | Jul. 28, 2018 USD ($)
Schedule of Investments [Line Items] |  |  |  |  |
Impairment charges of available-for-sale investments | $ 0 | $ 0 | $ 0 | $ 0 |
Average daily balance of securities lending |  |  | $ 1,300,000,000 | $ 300,000,000 |
Fair value of securities received as collateral that can be resold or repledged, percentage (at least) |  |  | 102.00% |  |
Secured lending transactions outstanding | $ 0 |  | $ 0 |  | $ 0
Number of variable interest entities required to be consolidated (entity) | entity | 0 |  | 0 |  |
Investments in privately held companies | $ 1,300,000,000 |  | $ 1,300,000,000 |  |
Funding commitments | 345,000,000 |  | 345,000,000 |  |
Variable Interest Entity, Not Primary Beneficiary |  |  |  |  |
Schedule of Investments [Line Items] |  |  |  |  |
Investments in privately held companies | $ 683,000,000 |  | $ 683,000,000 |  |

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