Allowance for Doubtful Accounts - Narrative (Details) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2016 USD ($) segments class	Apr. 30, 2015 USD ($)	Apr. 30, 2016 USD ($) segments class	Apr. 30, 2015 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loss on Contract Termination for Default	$ 0	$ 1	$ 1	$ 1
Number of Portfolio Segments for Finance Receivables | segments	2		2
Classes Of Receivables In Each Portfolio | class	1		1
Retail Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Average Recorded Investment			$ 21	$ 25