Financial Instruments - Pre-tax Effect of Derivative Instruments and Related Hedged Items in a Fair Value Hedging Relationship (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Apr. 30, 2018 |
Apr. 30, 2017 |
Apr. 30, 2018 |
Apr. 30, 2017 |
|
| Interest rate contracts | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Gains (Losses) Recognized in Earnings on Derivative | $ (72) | $ 37 | $ (210) | $ (225) |
| Gains (Losses) Recognized in Earnings on Related Hedged Item | 72 | (37) | 210 | 225 |
| Cash flow hedges | Foreign exchange contracts | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Gains (Losses) Recognized in Other Comprehensive Income (OCI) on Derivatives (Effective Portion) | 82 | 4 | (99) | 140 |
| Interest and other, net | Cash flow hedges | Foreign exchange contracts | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Gains (Losses) Recognized in Other Comprehensive Income (OCI) on Derivatives (Effective Portion) | $ (35) | $ 66 | $ (37) | $ 142 |