XML 19 R39.htm IDEA: XBRL DOCUMENT v2.4.0.8
Asset Retirement Obligation - Asset Retirement Obligation (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2014
Mar. 31, 2013
Dec. 31, 2013
Asset Retirement Obligation Disclosure [Abstract]      
Asset retirement obligation at December 31, 2013 $ 3,222    
Liabilities incurred 27    
Liabilities divested (91)    
Liabilities settled (24)    
Accretion expense 44 63  
Asset retirement obligation at March 31, 2014 3,178    
Less current portion (182)   (121)
Asset retirement obligation, long-term $ 2,996   $ 3,101