Supplemental Information on Oil and Gas Exploration and Production Activities (Unaudited) - Capitalized Costs Related to Oil and Gas Producing Activities (Details) - USD ($) $ in Thousands |
Dec. 31, 2019 |
Dec. 31, 2018 |
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| Reserve Quantities [Line Items] | ||
| Proved properties | $ 8,909,069 | $ 7,153,799 |
| Unproved properties | 1,686,666 | 2,873,037 |
| Capitalized costs, gross | 10,595,735 | 10,026,836 |
| Accumulated depreciation, depletion, amortization and impairment | (7,191,957) | (4,613,293) |
| Net capitalized costs | 3,403,778 | 5,413,543 |
| Investment in Grizzly Oil Sands ULC | ||
| Reserve Quantities [Line Items] | ||
| Proved properties | 64,476 | 67,475 |
| Unproved properties | 85,395 | 79,605 |
| Capitalized costs, gross | 149,871 | 147,080 |
| Accumulated depreciation, depletion, amortization and impairment | (1,634) | (1,553) |
| Net capitalized costs | $ 148,237 | $ 145,527 |
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- 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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- Definition The sum of capitalized costs relating to oil and gas producing activities before accounting for accumulated depreciation. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- 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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- Definition Capitalized costs of proved properties incurred for any combination mineral interests acquisitions; wells and related equipment; support equipment and facilities; and uncompleted wells and equipment and other costs not previously disclosed within this table. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Capitalized costs of unproved properties incurred for any combination mineral interests acquisitions and other costs not previously disclosed within this table. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Details
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