Other Income, Net Other Income (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
May 17, 2011
Debt Instrument [Line Items]      
Loss on extinguishment of debt $ (52) $ (34)  
Gain on insurance recovery 0 14  
Notes Payable, Other Payables | Senior Notes, 6.125% Due 2021      
Debt Instrument [Line Items]      
Debt Instrument, Interest Rate, Stated Percentage 6.125%   6.125%
Loss on extinguishment of debt $ (52)