Financial Instruments - Long-Term Debt Outstanding Maturities (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Debt Instrument [Line Items]
2014	$ 1,251
2015	3,057
2016	4,706
2017	1,850
After 2017	20,617
Total	$ 31,481	[1],[2],[3]	$ 31,036	[1],[2],[3]

[1] The fair value of our long-term debt (not including the current portion of long-term debt) is $37.8 billion as of March 31, 2013 and $37.5 billion as of December 31, 2012. The fair value measurements for our long-term debt are based on Level 2 inputs, using a market approach.

[2] Includes foreign currency debt with fair values of $735 million as of March 31, 2013 and $809 million as of December 31, 2012, which are used as hedging instruments.

[3] Some carrying amounts may include adjustments for discount or premium amortization or for the effect of interest rate swaps designated as hedges.