v2.4.0.6
Asset Retirement Obligations and Accrued Environmental Costs - Asset Retirement Obligations and Accrued Environmental Costs (Detail) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Asset retirement obligations $ 8,920 $ 8,776 $ 8,295
Accrued environmental costs 922 994  
Total asset retirement obligations and accrued environmental costs 9,842 9,770  
Asset retirement obligations and accrued environmental costs due within one year (513) (571)  
Long-term asset retirement obligations and accrued environmental costs $ 9,329 [1] $ 9,199 [1]  
[1] Certain amounts have been restated to reflect a prior period adjustment. See Note 21-Accumulated Other Comprehensive Income, in the Notes to Consolidated Financial Statements.