Financial Instruments (Net investment hedges in foreign operations) (Details) (Net Investment Hedge [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Net investment hedges in foreign operation
Hedge ineffectiveness gain (loss)	$ (183)	$ (386)	$ (663)	$ (1,041)
Foreign Exchange Contract [Member]
Net investment hedges in foreign operation
Gain (loss) recognized in AOCI	(2,939)	1,948	(2,588)	(1,458)
Gain (loss) reclassified from AOCI into earnings	$ 39	$ (15)	$ 27	$ (713)