Financial Instruments - Cash Equivalents and Available-for-Sale Investments (Details) - USD ($)
$ in Millions |
Apr. 30, 2018 |
Oct. 31, 2017 |
| Cash and Cash Equivalents [Line Items] |
|
|
| Debt securities, Amortized Cost |
$ 152
|
|
| Debt securities, Fair Value |
173
|
|
| Total cash and equivalents and available-for-sale investments, Cost basis |
5,196
|
$ 6,971
|
| Gross Unrealized Gain |
23
|
40
|
| Gross Unrealized Loss |
(2)
|
(11)
|
| Total cash equivalents and available-for-sale investments |
5,217
|
7,000
|
| Cost |
|
|
| Cash and Cash Equivalents [Line Items] |
|
|
| Total cash equivalents |
5,044
|
6,751
|
| Cost | Time deposits |
|
|
| Cash and Cash Equivalents [Line Items] |
|
|
| Total cash equivalents |
1,653
|
1,159
|
| Cost | Money market funds |
|
|
| Cash and Cash Equivalents [Line Items] |
|
|
| Total cash equivalents |
3,391
|
5,592
|
| Fair Value |
|
|
| Cash and Cash Equivalents [Line Items] |
|
|
| Total cash equivalents |
5,044
|
6,751
|
| Fair Value | Time deposits |
|
|
| Cash and Cash Equivalents [Line Items] |
|
|
| Total cash equivalents |
1,653
|
1,159
|
| Fair Value | Money market funds |
|
|
| Cash and Cash Equivalents [Line Items] |
|
|
| Total cash equivalents |
3,391
|
5,592
|
| Debt securities |
|
|
| Cash and Cash Equivalents [Line Items] |
|
|
| Debt securities, Amortized Cost |
152
|
220
|
| Debt securities, Gross Unrealized Gain |
23
|
40
|
| Debt securities, Gross Unrealized Loss |
(2)
|
(11)
|
| Debt securities, Fair Value |
173
|
249
|
| Time deposits |
|
|
| Cash and Cash Equivalents [Line Items] |
|
|
| Debt securities, Amortized Cost |
3
|
0
|
| Debt securities, Gross Unrealized Gain |
0
|
0
|
| Debt securities, Gross Unrealized Loss |
0
|
0
|
| Debt securities, Fair Value |
3
|
0
|
| Foreign bonds |
|
|
| Cash and Cash Equivalents [Line Items] |
|
|
| Debt securities, Amortized Cost |
121
|
183
|
| Debt securities, Gross Unrealized Gain |
23
|
40
|
| Debt securities, Gross Unrealized Loss |
0
|
0
|
| Debt securities, Fair Value |
144
|
223
|
| Other debt securities |
|
|
| Cash and Cash Equivalents [Line Items] |
|
|
| Debt securities, Amortized Cost |
28
|
37
|
| Debt securities, Gross Unrealized Gain |
0
|
0
|
| Debt securities, Gross Unrealized Loss |
(2)
|
(11)
|
| Debt securities, Fair Value |
$ 26
|
$ 26
|