Allowance for Doubtful Accounts - Narrative (Details) $ in Millions	12 Months Ended
	Oct. 31, 2017 USD ($) segments	Oct. 31, 2016 segments class
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Portfolio Segments for Finance Receivables | segments	2	2
Classes Of Receivables In Each Portfolio | class		1
Retail Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Average Recorded Investment | $	$ 18