Financial Instruments (Free-standing derivatives) (Details) (Free Standing Derivatives [Member], USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Free standing derivatives
Gain (loss) on derivatives	$ 668	$ (1,052)
Interest Rate Contract [Member]
Free standing derivatives
Gain (loss) on derivatives	(3)	(79)
Foreign Exchange Contract [Member]
Free standing derivatives
Gain (loss) on derivatives	682	(997)
Other Contract [Member]
Free standing derivatives
Gain (loss) on derivatives	$ (11)	$ 24