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 | 9 Months Ended | ||
|---|---|---|---|---|
Jul. 31, 2018 |
Jul. 31, 2017 |
Jul. 31, 2018 |
Jul. 31, 2017 |
|
| Interest rate contracts | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Gains (Losses) Recognized in Earnings on Derivative | $ 16 | $ 23 | $ (194) | $ (202) |
| Gains (Losses) Recognized in Earnings on Related Hedged Item | (16) | (23) | 194 | 202 |
| Cash flow hedges | Foreign exchange contracts | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Gains (Losses) Recognized in Other Comprehensive Income (OCI) on Derivatives (Effective Portion) | 149 | (133) | 50 | 7 |
| 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) | $ 28 | $ 28 | $ (9) | $ 170 |