Financial Instruments (Free-standing derivatives) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Free standing derivatives
Gain (loss) on derivatives		$ (603)
Free Standing Derivatives [Member]
Free standing derivatives
Gain (loss) on derivatives	$ (2,585)
Interest Rate Contract
Free standing derivatives
Gain (loss) on derivatives	(101)
Interest Rate Contract | Free Standing Derivatives [Member]
Free standing derivatives
Gain (loss) on derivatives		(53)
Foreign Exchange Contract
Free standing derivatives
Gain (loss) on derivatives	(2,486)
Foreign Exchange Contract | Free Standing Derivatives [Member]
Free standing derivatives
Gain (loss) on derivatives		(553)
Other Contract [Member]
Free standing derivatives
Gain (loss) on derivatives	$ 2	$ 3