Indemnifications (Details) - USD ($) $ in Millions	Jan. 31, 2018	Oct. 31, 2017
Tax Indemnification
Other Commitments [Line Items]
Receivable - long-term	$ 847	$ 1,430
Payables - short-term	372	36
Cross-Indemnifications
Other Commitments [Line Items]
Receivable	145	150
Payable	$ 93	$ 91