Derivative and Financial Instruments - Financial Instruments (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Financial Instruments
Cash	$ 829	$ 1,169
Cash and Cash Equivalents, at Carrying Value, Total	3,618	5,780		9,454	542
Short-term Investments		581	[1]
Remaining maturities from 1 to 90 days [Member]
Financial Instruments
Time Deposits	2,789	4,318
Commercial Paper		293
Time Deposits [Member] | Remaining maturities from 1 to 90 days [Member]
Financial Instruments
Short-term Investments		349
Commercial Paper [Member] | Remaining maturities from 1 to 90 days [Member]
Financial Instruments
Short-term Investments		$ 232

[1] *Includes marketable securities of: $0, $232