Financial Instruments (Free-standing derivatives) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Free Standing Derivatives [Member]
Free standing derivatives
Gain (loss) on derivatives	$ (600)	$ (1,127)
Interest Rate Contract [Member]
Free standing derivatives
Gain (loss) on derivatives	(24)	(82)
Foreign Exchange Contract [Member]
Free standing derivatives
Gain (loss) on derivatives	(569)	(1,065)
Other Contract [Member]
Free standing derivatives
Gain (loss) on derivatives	$ (7)	$ 20