Warranty Obligations (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]  
Accrual balance at beginning of period $ 146
Provision for estimated warranties incurred during the period 25
Provision for changes in estimate for pre-existing warranties 3
Settlements made during the period (in cash or in kind) (24)
Foreign currency translation and other (7)
Accrual balance at end of period $ 143