XML 68 R57.htm IDEA: XBRL DOCUMENT v3.7.0.1
ASSET RETIREMENT OBLIGATIONS (Details)
$ in Thousands
6 Months Ended
Jun. 30, 2017
USD ($)
Activity related to ARO liability  
Liability for asset retirement obligations at the beginning of the period $ 32,375
Liabilities settled and divested (8,342)
Additions 176
Acquisitions 2,194
Accretion expense 856
Liability for asset retirement obligations at the end of the period $ 27,259