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Oil and Gas Reserves Information (Unaudited) - Summary of Changes in Net Quantities of Crude Oil and Natural Gas Reserves (Detail) | 5 Months Ended | 7 Months Ended | 12 Months Ended |  |
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Dec. 31, 2018 MBbls | Dec. 31, 2018 MMcf MBbls | Dec. 31, 2018 MBbls MMBbls | Aug. 13, 2018 MBbls MMcf | Dec. 31, 2020 MMcf MMBbls Bcf | Dec. 31, 2019 MMcf MBbls MMBbls | Dec. 31, 2019 MMcf MMBbls | Dec. 31, 2019 MMcf MMBbls | Dec. 31, 2019 MMcf Bcf MMBbls | Dec. 31, 2018 MBbls | Dec. 31, 2018 MBbls MMcf | Dec. 31, 2018 MBbls Bcf | Dec. 31, 2018 MMcf | Dec. 31, 2018 MMBbls | Dec. 31, 2017 MBbls MMcf
Changes in Oil Prices |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proved Reserves: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revisions of previous estimates | Bcf |  |  |  |  | 2.9 |  |  |  | 0.5 |  |  | 0 |  |  |
Changes in Natural Gas Prices [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proved Reserves: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revisions of previous estimates | Bcf |  |  |  |  | 68.2 |  |  |  | 228.5 |  |  | 0 |  |  |
Oil (MBbls) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proved Reserves: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning of period | 28,994 |  |  |  | 16,747 | 23,612 |  | 23,612 |  |  |  |  |  |  |
Revisions of previous estimates | 5 |  |  |  | (4,241) |  |  | (4,621) |  |  |  |  |  |  |
Extensions and discoveries | 0 |  |  |  | 2 | 259 |  |  |  |  |  |  |  |  |
Acquisitions of minerals in place | 0 |  |  |  | 0 | 240 |  |  |  |  |  |  |  |  |
Sales of minerals in place | (4,002) |  |  |  | 0 |  |  | (58) |  |  |  |  |  |  |
Production | (1,385) |  |  |  | (1,508) |  |  | (2,685) |  |  |  |  |  |  |
End of period | 23,612 |  | 23,612 | 28,994 | 11,000 |  |  | 16,747 |  | 23,612 |  |  |  |  |
Proved Developed Reserves: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proved Developed Reserves | 21,466 | 21,466 | 21,466 | 22,845 | 11,000 | 15,104 | 15,104 | 15,104 | 15,104 | 21,466 | 21,466 | 21,466 |  | 21,466 |
Proved Undeveloped Reserves: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proved Undeveloped Reserves | 2,146 | 2,146 | 2,146 | 6,149 | 0 | 1,643 | 1,643 | 1,643 | 1,643 | 2,146 | 2,146 | 2,146 |  | 2,146 |
Oil (MBbls) | Predecessor |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proved Reserves: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning of period | MBbls | 6,050 |  |  | 7,552 |  |  |  |  |  | 7,552 |  |  |  |  |
Revisions of previous estimates | MBbls |  |  |  | 4 |  |  |  |  |  |  |  |  |  |  |
Extensions and discoveries | MBbls |  |  |  | 5,651 |  |  |  |  |  |  |  |  |  |  |
Acquisitions of minerals in place | MBbls |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |
Sales of minerals in place | MBbls |  |  |  | (6,870) |  |  |  |  |  |  |  |  |  |  |
Production | MBbls |  |  |  | (287) |  |  |  |  |  |  |  |  |  |  |
End of period | MBbls |  |  |  | 6,050 |  |  |  |  |  |  |  |  |  |  |
Proved Developed Reserves: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proved Developed Reserves | MBbls |  |  |  | 403 |  |  |  |  |  |  |  |  |  |  | 7,552
Proved Undeveloped Reserves: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proved Undeveloped Reserves | MBbls |  |  |  | 5,647 |  |  |  |  |  |  |  |  |  |  | 0
Natural Gas (MMcf) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proved Reserves: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning of period |  | 2,246,501 |  |  | 5,341,497 |  | 2,282,758 |  |  |  |  |  |  |  |
Revisions of previous estimates |  | 23,949 |  |  | 306,552 |  | 62,697 |  |  |  |  |  |  |  |
Extensions and discoveries |  | 30,126 |  |  | 365,663 |  | 315,286 |  |  |  |  |  |  |  |
Acquisitions of minerals in place |  | 33,612 |  |  | 0 |  | 3,023,109 |  |  |  |  |  |  |  |
Sales of minerals in place |  | (6,399) |  |  | 0 |  | (49,520) |  |  |  |  |  |  |  |
Production |  | (45,031) |  |  | (450,836) |  | (292,833) |  |  |  |  |  |  |  |
End of period |  | 2,282,758 |  | 2,246,501 | 5,562,876 |  | 5,341,497 |  |  |  | 2,282,758 |  |  |  |
Proved Developed Reserves: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proved Developed Reserves |  |  |  | 550,198 | 1,967,288 | 1,890,357 | 1,890,357 | 1,890,357 | 1,890,357 |  |  |  | 583,107 |  |
Proved Undeveloped Reserves: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proved Undeveloped Reserves |  |  |  | 1,696,303 | 3,595,588 | 3,451,140 | 3,451,140 | 3,451,140 | 3,451,140 |  |  |  | 1,699,651 |  |
Natural Gas (MMcf) | Predecessor |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proved Reserves: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Beginning of period |  | 2,195,273 |  | 1,116,956 |  |  |  |  |  |  | 1,116,956 |  |  |  |
Revisions of previous estimates |  |  |  | 17,778 |  |  |  |  |  |  |  |  |  |  |
Extensions and discoveries |  |  |  | 950,032 |  |  |  |  |  |  |  |  |  |  |
Acquisitions of minerals in place | MBbls |  |  |  | 220,088 |  |  |  |  |  |  |  |  |  |  |
Sales of minerals in place |  |  |  | (54,341) |  |  |  |  |  |  |  |  |  |  |
Production |  |  |  | (55,240) |  |  |  |  |  |  |  |  |  |  |
End of period |  |  |  | 2,195,273 |  |  |  |  |  |  |  |  |  |  |
Proved Developed Reserves: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proved Developed Reserves |  |  |  | 500,031 |  |  |  |  |  |  |  |  |  |  | 436,114
Proved Undeveloped Reserves: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proved Undeveloped Reserves |  |  |  | 1,695,242 |  |  |  |  |  |  |  |  |  |  | 680,842

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- Definition Additions to proved reserves that result from (1) extension of the proved acreage of previously discovered (old) reservoirs through additional drilling in periods after discovery and (2) discovery of new fields with proved reserves or of new reservoirs of proved reserves in old fields. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher SEC -Name Form 20-F -Section Item 18 -Subsection Instruction 2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 5 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61831-109447 + Details
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- Definition The net quantity of proved reserves as of the balance sheet date. Proved oil reserves are the estimated quantities of crude oil and natural gas liquids which geological and engineering data demonstrate with reasonable certainty to be recoverable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher SEC -Name Form 20-F -Section Item 18 -Subsection Instruction 2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61797-109447 + Details
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