Overview and Basis of Presentation (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | |
|---|---|---|---|
Jul. 31, 2018 |
Jul. 31, 2018 |
Jul. 31, 2017 |
|
| Segment Reporting Information [Line Items] | |||
| Net excess tax benefits | $ 26 | $ 68 | |
| Net cash provided by (used in) operating activities | 1,638 | $ 504 | |
| Net cash provided by financing activities | $ (4,341) | (1,310) | |
| Accounting Standards Update 2016-09, Statutory Tax Withholding Component | |||
| Segment Reporting Information [Line Items] | |||
| Net cash provided by (used in) operating activities | 441 | ||
| Net cash provided by financing activities | $ 441 | ||