Fair Value - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Apr. 30, 2018	Oct. 31, 2017
Assets
Total assets	$ 5,456	$ 7,260
Liabilities
Total liabilities	678	477
Time deposits
Assets
Total assets	1,656	1,159
Money market funds
Assets
Total assets	3,391	5,592
Foreign bonds
Assets
Total assets	144	223
Other debt securities
Assets
Total assets	26	26
Foreign exchange contracts
Assets
Total assets	238	259
Liabilities
Total liabilities	326	335
Other derivatives
Assets
Total assets	1	1
Interest rate contracts
Liabilities
Total liabilities	352	142
Level 1
Assets
Total assets	3,400	5,601
Liabilities
Total liabilities	0	0
Level 1 | Time deposits
Assets
Total assets	0	0
Level 1 | Money market funds
Assets
Total assets	3,391	5,592
Level 1 | Foreign bonds
Assets
Total assets	9	9
Level 1 | Other debt securities
Assets
Total assets	0	0
Level 1 | Foreign exchange contracts
Assets
Total assets	0	0
Liabilities
Total liabilities	0	0
Level 1 | Other derivatives
Assets
Total assets	0	0
Level 1 | Interest rate contracts
Liabilities
Total liabilities	0	0
Level 2
Assets
Total assets	2,030	1,633
Liabilities
Total liabilities	678	477
Level 2 | Time deposits
Assets
Total assets	1,656	1,159
Level 2 | Money market funds
Assets
Total assets	0	0
Level 2 | Foreign bonds
Assets
Total assets	135	214
Level 2 | Other debt securities
Assets
Total assets	0	0
Level 2 | Foreign exchange contracts
Assets
Total assets	238	259
Liabilities
Total liabilities	326	335
Level 2 | Other derivatives
Assets
Total assets	1	1
Level 2 | Interest rate contracts
Liabilities
Total liabilities	352	142
Level 3
Assets
Total assets	26	26
Liabilities
Total liabilities	0	0
Level 3 | Time deposits
Assets
Total assets	0	0
Level 3 | Money market funds
Assets
Total assets	0	0
Level 3 | Foreign bonds
Assets
Total assets	0	0
Level 3 | Other debt securities
Assets
Total assets	26	26
Level 3 | Foreign exchange contracts
Assets
Total assets	0	0
Liabilities
Total liabilities	0	0
Level 3 | Other derivatives
Assets
Total assets	0	0
Level 3 | Interest rate contracts
Liabilities
Total liabilities	$ 0	$ 0