Servicing Activities Servicing Activities (Narrative - Automobile Servicing Activities) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Servicing Activities [Abstract]
Automobile Servicing Fees	$ 26	$ 39	$ 86	$ 126