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Summary of Significant Accounting Policies - Summary of Changes in Reserve for Future Abandonment Costs (Detail) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2021
Mar. 31, 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 328 186
Liabilities settled and assets disposed of 0 (11)
Accretion expense 297 287
Reserve for future abandonment costs at end of period $ 19,915 $ 18,613