XML 69 R58.htm IDEA: XBRL DOCUMENT v3.21.2
Asset Retirement Obligations - Asset Retirement Obligations (Detail) - USD ($)
$ in Thousands
9 Months Ended 12 Months Ended
Sep. 30, 2021
Dec. 31, 2020
Asset Retirement Obligation [Abstract]    
Beginning of period $ 79,822 $ 251,076
Liabilities incurred 88 1,483
Acquisitions 0 123
Liabilities settled (5,719) (4,634)
Disposition of wells 0 (176,748)
Accretion expense 4,257 7,518
Change in estimate 2,856 1,004
End of period 81,304 79,822
Less current portion (6,689) (6,689)
Long-term asset retirement obligations $ 74,615 $ 73,133