v2.4.1.9
ASSET RETIREMENT OBLIGATION (Tables)
3 Months Ended
Mar. 31, 2015
Asset Retirement Obligation Disclosure [Abstract]  
Schedule of Changes to Asset Retirement Obligation
Following is a table of the changes to our asset retirement obligation for the following periods (in thousands):
 
 
Three Months Ended March 31,
 
 
2015
 
2014
Asset retirement obligation, at beginning of period
 
$
22,037

 
$
21,047

Liabilities settled
 

 
(77
)
Liabilities incurred
 

 

Changes in estimated obligations
 

 

Accretion of discount
 
424

 
406

Total asset retirement obligation, at end of period
 
$
22,461

 
$
21,376