v2.4.0.8
Suspended Wells (Details) (USD $)
In Millions, unless otherwise specified
6 Months Ended
Jun. 30, 2013
Dec. 31, 2012
Suspended Wells (Textual) [Abstract]    
Capitalized cost of suspended wells $ 915 $ 1,038
Increase (decrease) in capitalized cost of suspended wells $ (123)