XML 42 R35.htm IDEA: XBRL DOCUMENT v2.4.0.8
Asset retirement obligations (“ARO”) (Tables)
3 Months Ended
Mar. 31, 2014
Asset Retirement Obligation Disclosure [Abstract]  
Schedule of changes in asset retirement obligations
The reconciliation of the changes in the asset retirement obligations is presented below:
 
Three months ended March 31, 2014
Year ended December 31, 2013
Beginning balance, ARO liability
$
27,113

$
16,124

Additional ARO liability incurred
794

1,730

ARO liabilities settled
(791
)
(2,580
)
Accretion expense
282

1,733

Additional ARO liability from Sebree acquisition

10,106

Ending balance, ARO liability
$
27,398

$
27,113