XML 174 R82.htm IDEA: XBRL DOCUMENT v2.4.0.6
Properties, Plants, and Equipment, Net - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2012
Kmt
Dec. 31, 2011
Mg
Kmt
Smelting Assets [Member]
    
Property, Plant and Equipment [Line Items]    
Net carrying value of assets $ 325 $ 166
Net carrying value of other idled smelting assets written off   291
Idle capacity of assets, units 591 353
Idled Refining Assets [Member]
    
Property, Plant and Equipment [Line Items]    
Net carrying value of assets $ 68 $ 65
Idle capacity of assets, units 1,277 1,177