Transfers of Receivables - Derivative Income and Expense (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivative expense/(income) related to securitization transactions [Abstract]
Derivative expense/(income)	$ 158	$ (207)	$ 95	$ (62)
Securitization Transactions [Member]
Derivative expense/(income) related to securitization transactions [Abstract]
Derivative expense/(income)	(36)	78	(3)	(6)
Securitization Transactions [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Derivative expense/(income) related to securitization transactions [Abstract]
Derivative expense/(income)	(22)	73	(4)	(20)
Related to Variable Interest Entity - Not VIE [Member] | Securitization Transactions [Member]
Derivative expense/(income) related to securitization transactions [Abstract]
Derivative expense/(income)	(10)	(2)	(10)	8
Other, Not Variable Interest Entity Related [Member] | Securitization Transactions [Member]
Derivative expense/(income) related to securitization transactions [Abstract]
Derivative expense/(income)	$ (4)	$ 7	$ 11	$ 6