v3.2.0.727
Fair Value Measurements Other Fair Value Measurements (Details) - USD ($)
$ in Millions
Jun. 30, 2015
Dec. 31, 2014
Other Fair Value Measurements [Line Items]    
Carrying value of long-term debt and current portion of long-term debt $ 8,612 $ 9,032
Level 2 [Member]    
Other Fair Value Measurements [Line Items]    
Fair value of long-term debt and current portion of long-term debt $ 8,879 $ 9,509