Geographic Area Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2011	Oct. 31, 2012 item	Oct. 31, 2011	Oct. 31, 2010
Geographic Area Information
Number of operating segments									1
Geographic Area Information
Revenues	$ 443.7	$ 422.7	$ 413.3	$ 394.9	$ 413.8	$ 414.0	$ 399.3	$ 394.3	$ 1,674.6	$ 1,621.4	$ 1,682.3
Operating profit (loss)									601	572	478
Receivables	25,204.3				22,078.6				25,204.3	22,078.6	19,860.0
U.S.
Geographic Area Information
Revenues									1,446.0	1,387.0	1,496.0
Operating profit (loss)									494	474	409
Receivables	21,554.0				18,618.0				21,554.0	18,618.0	16,918.0
Outside the U.S.
Geographic Area Information
Revenues									229.0	234.0	186.0
Operating profit (loss)									107	98	69
Receivables	$ 3,650.0				$ 3,461.0				$ 3,650.0	$ 3,461.0	$ 2,942.0