Income Taxes (Additional Information) (Details) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended | |
|---|---|---|---|
Oct. 27, 2018 |
Oct. 28, 2017 |
Jul. 28, 2018 |
|
| Income Tax Contingency [Line Items] | |||
| Benefit for provision for income taxes | $ (360) | $ (568) | |
| Tax Cuts and Jobs Act of 2017, provisional tax expense | $ 10,400 | ||
| Tax Cuts and Jobs Act of 2017, transition tax expense (benefit) | 8,100 | $ (863) | |
| Tax Cuts and Jobs Act of 2017, tax expense for foreign withholding tax | 1,200 | ||
| Tax Cuts and Jobs Act of 2017, re-measurement of net deferred tax assets | 1,100 | ||
| Unrecognized tax benefits | 1,900 | ||
| Unrecognized tax benefits that would impact effective tax rate | 1,700 | ||
| Unrecognized tax benefit that could be reduced in next 12 months | 200 | ||
| Accounting Standards Update 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606 | |||
| Income Tax Contingency [Line Items] | |||
| Benefit for provision for income taxes | $ 152 | ||