Financial Instruments (Free-standing derivatives) (Details) (Free Standing Derivatives [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Free standing derivatives
Gain (loss) on derivatives	$ (802)	$ (185)
Interest Rate Contract [Member]
Free standing derivatives
Gain (loss) on derivatives	(103)	(291)
Foreign Exchange Contract [Member]
Free standing derivatives
Gain (loss) on derivatives	(733)	113
Other Contract [Member]
Free standing derivatives
Gain (loss) on derivatives	$ 34	$ (7)