Supplementary Financial Information - Other Non-Current Liabilities (Details) - USD ($) $ in Millions	Oct. 31, 2019	Oct. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Tax liability	$ 848	$ 2,063
Pension, post-retirement, and post-employment liabilities	1,762	1,645
Deferred revenue	1,069	1,005
Deferred tax liability	60	100
Other	848	793
Other non-current liabilities	$ 4,587	$ 5,606