Derivative Instruments (Details 2) (USD $) In Millions, unless otherwise specified	Apr. 30, 2013	Oct. 31, 2012	Apr. 30, 2012
Interest rate contracts
Derivatives Not Designated as Hedging Instruments
Notional amounts	$ 2,436	$ 2,380	$ 2,109
Foreign Exchange Contracts
Derivatives Not Designated as Hedging Instruments
Notional amounts	1,756	1,298	1,362
Cross-Currency Interest Rate Contracts
Derivatives Not Designated as Hedging Instruments
Notional amounts	79	78	71
Interest Rate Caps- Purchased
Derivatives Not Designated as Hedging Instruments
Notional amounts	1,434	1,445	1,345
Interest Rate Caps- Sold
Derivatives Not Designated as Hedging Instruments
Notional amounts	$ 1,434	$ 1,445	$ 1,345