Note 19 - Supplemental Oil and Gas Disclosures - Cost Incurred in Oil and Gas Property Acquisition Exploration and Development Activities (Details) - USD ($) $ in Millions |
12 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
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| Costs incurred: (1) | |||||||||
| Proved properties acquisitions | [1] | $ 8.1 | $ 223.8 | $ 24.1 | |||||
| Exploration (2) (3) | [1],[2],[3] | 7.4 | 30.6 | 49.9 | |||||
| Development | [1] | 23.6 | 114.5 | 56.2 | |||||
| Total costs incurred in oil and gas property acquisition, exploration and development activities | [1] | $ 39.1 | $ 368.9 | $ 130.2 | |||||
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| X | ||||||||||
- Definition Costs incurred, including capitalized costs and costs charged to expense, associated with the acquisition of oil and gas properties that have proved reserves. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Development costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Exploration costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount of costs incurred related to oil and gas property acquisition, exploration and development activities, including capitalized costs and costs charged to expense. No definition available.
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| X | ||||||||||
- References No definition available.
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