Allowance for Doubtful Accounts - Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jan. 31, 2013 class	Jan. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable By Class Number of Portfolio Segments	2
Retail Portfolio [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$ 14	$ 13
Financing Receivable Number Of Classes Of Receivables In Each Portfolio	1
Wholesale Portfolio [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable Number Of Classes Of Receivables In Each Portfolio	1