Pension and Other Postretirement Benefits - Effect of Foreign Plans (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Pension Benefits [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Defined benefit plan cost $ 0 $ 5
Other Postretirement Benefits [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Defined benefit plan cost $ 2 $ 2