XML 41 R30.htm IDEA: XBRL DOCUMENT v2.4.0.6
Asset Retirement Obligations (Tables)
 3 Months Ended
Mar. 31, 2013
Asset Retirement Obligations  
Schedule of changes in carrying amount of asset retirement obligations

Changes in the carrying amount of our AROs were as follows (in thousands):

 

 

 

2013

 

Balance at January 1,

 

$

240,634

 

Accretion expense

 

4,127

 

Revisions to estimated cash flows

 

(2,057

)

Payments

 

(327

)

Balance at March 31,

 

242,377

 

Less: current portion

 

(3,693

)

Asset retirement obligation, net of current portion

 

$

238,684