Restructuring - Narrative (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Apr. 30, 2018 |
Apr. 30, 2017 |
Apr. 30, 2018 |
Apr. 30, 2017 |
Oct. 31, 2017 |
|
| Restructuring Cost and Reserve [Line Items] | |||||
| Restructuring charges | $ 9 | $ 69 | $ 12 | $ 152 | |
| Current restructuring liability reported in Accrued restructuring | 286 | 286 | $ 445 | ||
| Non-current restructuring liability reported in Other liabilities | 55 | 55 | 96 | ||
| All Restructuring Plan | |||||
| Restructuring Cost and Reserve [Line Items] | |||||
| Restructuring charges | 12 | ||||
| Current restructuring liability reported in Accrued restructuring | $ 64 | $ 64 | $ 158 | ||