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Summary of Significant Accounting Policies - Narrative (Details) | 12 Months Ended
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Dec. 31, 2020 USD ($) bbl | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($)
Summary Of Significant Accounting Policies [Line Items] |  |  |
Decrease in capital spending, percentage | 50.00% |  |
Accounts receivable, collection period | 30 days |  |
Allowance for doubtful accounts | $ 0 | $ 0 |
Impairment of oil and natural gas properties | $ 1,357,099,000 | 2,039,770,000 | $ 0
Conversion ratio, gas to barrels of oil (in Mcf of gas) | bbl | 6 |  |
Capitalized costs of oil and natural gas properties excluded from amortization | $ 1,457,043,000 | 1,686,666,000 |
Unrecognized tax benefits that would impact effective tax rate | 0 |  |
Equity method investment recognized impairment charges |  |  | 0
Unsecured Debt |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Debt instrument, repurchase amount | 73,300,000 |  |
Investment in Mammoth Energy Services, Inc. |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Equity method investment recognized impairment charges | 0 | 160,800,000 |
Investment in Grizzly Oil Sands ULC |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Equity method investment recognized impairment charges | $ 0 | $ 32,400,000 | $ 0
Minimum |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Useful life | 3 years |  |
Minimum | Restricted stock |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Vesting period | 1 year |  |
Maximum |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Useful life | 30 years |  |
Maximum | Restricted stock |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Vesting period | 3 years |  |

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