v2.4.0.6
Financial Instruments and Derivative Contracts - Fair Value of Derivative Contracts (Detail) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2011
Dec. 31, 2010
Prepaid expenses and other current assets [Member]
   
Assets    
Commodity derivative assets $ 12 $ 14
Other assets [Member]
   
Assets    
Commodity derivative assets 1 1
Other accruals [Member]
   
Liabilities    
Commodity derivative liabilities 23 7
Other liabilities and deferred credits [Member]
   
Liabilities    
Commodity derivative liabilities   $ 2