Summary of Significant Accounting Policies - Variable Interest Entities (Details) - USD ($) $ in Millions	Apr. 30, 2017	Oct. 31, 2016	Apr. 30, 2016	Oct. 31, 2015
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 771	$ 804	$ 589	$ 912
Variable Interest Entity Primary Beneficiary, Blue Diamond Parts [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	43	51
Cash and cash equivalents	12	6
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	17	16
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	900	900
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	703	722
Transaction Does Not Qualify for Sale Accounting [Member] | Financial Services Operations
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	254	249
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	$ 123	$ 136