Allowance for Doubtful Accounts - Narrative (Details) $ in Millions	9 Months Ended	12 Months Ended
	Jul. 31, 2014 USD ($)	Oct. 31, 2015 USD ($) segments class	Oct. 31, 2014 USD ($)	Oct. 31, 2013 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loss on Contract Termination for Default	$ 1	$ 1		$ 2
Number of Portfolio Segments for Finance Receivables | segments		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		$ 21	$ 21