Finance Receivables - Narrative (Details) $ in Millions	Jul. 31, 2020 USD ($) segments	Apr. 30, 2020 segments	Oct. 31, 2019 USD ($)
Schedule of Securitization [Line Items]
Loans and Leases Receivable, Net Amount	$ 1,700		$ 2,200
Number of Portfolio Segments for Finance Receivables | segments	2	2
Trac Funding Facility [Member]
Schedule of Securitization [Line Items]
Finance Receivables Retail Accounts Collateral For Borrowed Securities	$ 808		874
Cash Collateral for Borrowed Securities	137		358
Financial Services Operations
Schedule of Securitization [Line Items]
Assets Net Of Intercompany Balances	$ 2,300		$ 2,800