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Supplemental Oil and Gas Reserve Information - Developed and Undeveloped Oil and Gas Reserve (Details) MMBbls in Millions | May 03, 2021 MMBbls | Dec. 31, 2019 MMBoe MBbls Bcf
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Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (volume) | MMBbls | 583.5 |
Proved developed reserves (energy) | MMBoe |  | 129,200,000
Proved underdeveloped reserves | MMBbls | 22.6 |
Proved undeveloped reserves (energy) | MMBoe |  | 53,300,000
Oil |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (volume) |  | 85,400,000
Proved underdeveloped reserves |  | 34,300,000
Natural Gas Liquids |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (volume) |  | 0
Proved underdeveloped reserves |  | 0
Natural Gas |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (volume) | Bcf |  | 262,700,000
Proved underdeveloped reserves | Bcf |  | 113,500,000
Pro Forma |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (energy) | MMBoe |  | 178,900,000
Proved undeveloped reserves (energy) | MMBoe |  | 53,400,000
Pro Forma | Oil |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (volume) |  | 113,300,000
Proved underdeveloped reserves |  | 34,000,000.0
Pro Forma | Natural Gas Liquids |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (volume) |  | 12,800,000
Proved underdeveloped reserves |  | 1,600,000
Pro Forma | Natural Gas |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (volume) | Bcf |  | 316,900,000
Proved underdeveloped reserves | Bcf |  | 106,500,000
Permian Basin Sale |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (energy) | MMBoe |  | (16,700,000)
Proved undeveloped reserves (energy) | MMBoe |  | (13,700,000)
Permian Basin Sale | Oil |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (volume) |  | (13,200,000)
Proved underdeveloped reserves |  | (11,000,000.0)
Permian Basin Sale | Natural Gas Liquids |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (volume) |  | 0
Proved underdeveloped reserves |  | 0
Permian Basin Sale | Natural Gas |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (volume) | Bcf |  | (20,800,000)
Proved underdeveloped reserves | Bcf |  | (16,300,000)
Williston Basin Acquisition |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (energy) | MMBoe |  | 66,400,000
Proved undeveloped reserves (energy) | MMBoe |  | 13,800,000
Williston Basin Acquisition | Oil |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (volume) |  | 41,100,000
Proved underdeveloped reserves |  | 10,700,000
Williston Basin Acquisition | Natural Gas Liquids |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (volume) |  | 12,800,000
Proved underdeveloped reserves |  | 1,600,000
Williston Basin Acquisition | Natural Gas |  |
Oil and Gas Exploration and Production Industries [Line Items] |  |
Proved developed reserves (volume) | Bcf |  | 75,000,000.0
Proved underdeveloped reserves | Bcf |  | 9,300,000

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- Definition Energy measure of interests in proved developed reserves of crude oil, including condensate and natural gas liquids, natural gas, synthetic oil and gas, or other nonrenewable natural resource that is intended to be upgraded into synthetic oil and gas. + 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=123377692&loc=d3e61797-109447 + Details
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