XML 26 R46.htm IDEA: XBRL DOCUMENT v2.4.0.8
Asset Retirement Obligations (Details) (USD $)
In Thousands, unless otherwise specified
9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Dec. 31, 2012
Asset Retirement Obligation, Roll Forward Analysis      
Balance at December 31, 2012 $ 62,563    
Obligations incurred with development activities 337    
Accretion expense 3,667 2,839  
Revision in estimated cash flows 251    
Obligations discharged with disposal of properties and asset retirements (7,376)    
Balance at September 30, 2013 59,442    
Liabilities held for sale 22,788 [1]    
Less current portion 1,000    
Long-term portion $ 35,654   $ 61,563
[1] Represents asset retirement obligations related to our assets held for sale. See Note 12, Assets Held for Sale, Divestitures and Discontinued Operations and Note 15, Subsequent Events, for additional information regarding the potential sale of these properties.