Financial Instruments (Net investment hedges in foreign operations) (Details) (Net Investment Hedge [Member], USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended		12 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Jun. 30, 2012 Foreign Exchange Contract [Member]	Jun. 30, 2011 Foreign Exchange Contract [Member]	Jun. 30, 2012 Foreign Exchange Contract [Member]	Jun. 30, 2011 Foreign Exchange Contract [Member]
Net investment hedges in foreign operation
Gain (loss) recognized in AOCI					$ 1,853	$ (2,605)	$ 351	$ (3,406)
Gain (loss) reclassified from AOCI into earnings					(2)	(360)	(12)	(698)
Hedge ineffectiveness gain (loss)	$ (260)	$ (480)	$ (655)	$ (377)