Investments (Additional Information) (Details) |
3 Months Ended | ||
|---|---|---|---|
|
Oct. 29, 2016
USD ($)
entity
|
Oct. 24, 2015
USD ($)
|
Jul. 30, 2016
USD ($)
|
|
| Schedule of Investments [Line Items] | |||
| Other than temporary impairment, credit losses recognized in earnings, credit losses on debt securities held | $ 0 | ||
| Average daily balance of securities lending | $ 1,500,000,000 | $ 500,000,000 | |
| Fair value of securities received as collateral That can be resold or repledged, percentage | 102.00% | 102.00% | |
| Secured lending transactions outstanding | $ 0 | $ 0 | |
| Number of variable interest entities required to be consolidated | entity | 0 | ||
| Investments in privately held companies | $ 991,000,000 | $ 1,003,000,000 | |
| Funding commitments | 189,000,000 | ||
| Variable Interest Entity, Not Primary Beneficiary | |||
| Schedule of Investments [Line Items] | |||
| Investments in privately held companies | $ 609,000,000 | ||