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 | |||