XML 43 R37.htm IDEA: XBRL DOCUMENT v2.4.0.8
Asset Retirement Obligation (Tables)
12 Months Ended
Dec. 31, 2013
Asset Retirement Obligation Disclosure [Abstract]  
Information Related to Asset Retirement Obligation

The following table reflects information related to our asset retirement obligations:

 

Balance at December 31, 2011

   $  180,662   

Additions to asset retirement obligations

     5,434   

Accretion expense

     10,871   

Liabilities settled

     (7,308
  

 

 

 

Balance at December 31, 2012

     189,659   

Additions to asset retirement obligations

     3,741   

Accretion expense

     11,046   

Liabilities settled

     (3,615
  

 

 

 

Balance at December 31, 2013

   $ 200,831