Equity (Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Foreign currency translation adjustments	$ (799)	$ (896)
Cash flow hedges - unrealized net loss	(11)	(9)
Total accumulated other comprehensive income (loss)	(2,348)	(2,458)	[1]
Net Experience Loss [Member]
Postretirement and postemployment benefits	(1,470)	(1,483)
Prior Service Cost [Member]
Postretirement and postemployment benefits	$ (68)	$ (70)

[1] * Condensed from audited financial statements.