Summary of Significant Accounting Policies - Variable Interest Entities (Details) - USD ($) $ in Millions	Oct. 31, 2020	Oct. 31, 2019
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 1,843	$ 1,370
Variable Interest Entity Primary Beneficiary, Blue Diamond Parts [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets (Deprecated 2020-01-31)	37	32
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities (Deprecated 2020-01-31)	3	4
Cash and cash equivalents	4	2
Variable Interest Entity Primary Beneficiary Securitizations Treated As Borrowings [Member] | Financial Services Operations
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets (Deprecated 2020-01-31)	661	927
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities (Deprecated 2020-01-31)	610	838
Transaction Does Not Qualify for Sale Accounting [Member] | Financial Services Operations
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets (Deprecated 2020-01-31)	397	537
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities (Deprecated 2020-01-31)	$ 288	$ 279