v2.4.0.8
Fair Value Measurements Other Fair Value Measurements (Details) (USD $)
In Millions, unless otherwise specified
Jun. 30, 2013
Dec. 31, 2012
Fair Value Disclosures [Abstract]    
Carrying value of long-term debt and current portion of long-term debt $ 9,644 $ 10,076
Fair value of long-term debt and current portion of long-term debt $ 9,821 $ 10,793