Discontinued Operations - Cash flow (Details) - Enterprise Services - Discontinued Operations, Disposed of by Means Other than Sale, Spinoff - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Apr. 30, 2017 |
Apr. 30, 2016 |
Apr. 30, 2017 |
Apr. 30, 2016 |
|
| Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] | ||||
| Depreciation and amortization | $ 129 | $ 358 | $ 388 | $ 734 |
| Purchases of property, plant and equipment | $ 53 | $ 224 | $ 131 | $ 486 |