Note 20 - Supplemental Oil and Gas Disclosures - Unaudited - Capitalized Costs Related to Oil and Natural Gas (Details) - USD ($) $ in Millions |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|---|
| Net capitalized cost: | |||
| Proved oil and natural gas properties and equipment | $ 8,532.2 | $ 8,169.9 | $ 8,102.0 |
| Accumulated depreciation, depletion and amortization related to oil, NGLs and natural gas activities | (7,793.3) | (7,665.1) | (7,525.0) |
| Net capitalized costs related to producing activities | $ 738.9 | $ 504.8 | $ 577.0 |
| X | ||||||||||
- Definition Amount of accumulated depreciation, depletion, amortization and valuation allowance relating to oil and gas producing activities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Capitalized costs of proved properties that include fee ownership or a lease, concession, or other interest representing the right to extract oil or gas subject to such terms as may be imposed by the conveyance of that interest. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Net amount of capitalized costs relating to oil and gas producing activities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- References No definition available.
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