XML 59 R35.htm IDEA: XBRL DOCUMENT v3.3.1.900
ASSET RETIREMENT OBLIGATIONS Asset Retirement Obligations (Tables)
 12 Months Ended
Dec. 31, 2015
Asset Retirement Obligation Disclosure [Abstract]  
Schedule of Change in Asset Retirement Obligation [Table Text Block]
The following table presents the changes in carrying amounts of the asset retirement obligations associated with our working interest in crude oil and natural gas properties:
 
2015
 
2014
 
(in thousands)
 
 
 
 
Balance at beginning of period, January 1, 2015
$
73,855

 
$
41,030

Revisions in estimated cash flows
11,658

 
31,945

Obligations incurred with development activities
2,373

 
1,170

Accretion expense
6,293

 
3,455

Obligations discharged with asset retirements
(4,687
)
 
(3,745
)
Balance end of period, December 31, 2015
89,492

 
73,855

Less current portion
(5,460
)
 
(1,863
)
Long-term portion
$
84,032

 
$
71,992