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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Summary of Changes in Reserve for Future Abandonment Costs (Detail) - USD ($)
$ in Thousands
9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
Reserve for future abandonment costs at beginning of period $ 19,290 $ 18,151
New wells placed on production 1,666 451
Liabilities settled and assets disposed of (6) (80)
Accretion expense 917 880
Reserve for future abandonment costs at end of period $ 21,867 $ 19,402