Finance Receivables - Narrative (Details) $ in Millions	Jan. 31, 2018 USD ($) segments	Oct. 31, 2017 USD ($)
Schedule of Securitization [Line Items]
Loans and Leases Receivable, Net Amount	$ 1,700	$ 1,800
Number of Portfolio Segments for Finance Receivables | segments	2
Trac Funding Facility [Member]
Schedule of Securitization [Line Items]
Finance Receivables Retail Accounts Collateral For Borrowed Securities	$ 719	797
Cash Collateral for Borrowed Securities	132	163
Financial Services Operations
Schedule of Securitization [Line Items]
Assets Net Of Intercompany Balances	$ 2,100	$ 2,200