Supplementary Financial Information - Other Non-Current Liabilities (Details) - USD ($) $ in Millions	Jan. 31, 2018	Oct. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Pension, post-retirement, and post-employment liabilities	$ 1,930	$ 1,999
Deferred tax liability	100	1,410
Tax liability	4,254	2,005
Deferred revenue	945	921
Other	1,069	827
Other non-current liabilities	$ 8,298	$ 7,162