XML 44 R28.htm IDEA: XBRL DOCUMENT v3.8.0.1
Asset Retirement Obligations (Tables)
 12 Months Ended
Dec. 31, 2017
Asset Retirement Obligation Disclosure [Abstract]  
Schedule of changes in Company's asset retirement obligations
The following table summarizes the changes in the Company’s asset retirement obligations for the years ended December 31, 2017 and 2016 (in thousands). 
 
 
Year Ended December 31,
 
 
2017
 
2016
Beginning asset retirement obligations
 
$
20,640

 
$
15,420

Liabilities incurred during period
 
2,920

 
1,791

Liabilities settled during period
 
(430
)
 
(375
)
Revisions in estimated cash flows
 
1,836

 
2,622

Accretion expense
 
1,290

 
1,182

Ending asset retirement obligations
 
26,256

 
20,640

Less: current asset retirement obligations (1)
 
(1,176
)
 
(915
)
Long-term asset retirement obligations
 
$
25,080

 
$
19,725


__________________
(1)
Included in accrued liabilities in the Company’s consolidated balance sheets at December 31, 2017 and 2016.