XML 82 R71.htm IDEA: XBRL DOCUMENT v3.19.2
Asset Retirement Obligations - Asset Retirement Obligations (Detail) - USD ($)
$ in Thousands
6 Months Ended 12 Months Ended
Jun. 30, 2019
Dec. 31, 2018
Asset Retirement Obligation [Abstract]    
Beginning of period $ 312,754 $ 276,855
Liabilities incurred 2,529 3,376
Acquisitions   13,438
Liabilities settled (2,582) (5,052)
Disposition of wells   (13,332)
Accretion expense 8,487 25,456
Change in estimate (203) 12,013
End of period 320,985 312,754
Less current portion (5,485) (5,485)
Long-term asset retirement obligations $ 315,500 $ 307,269