Derivatives - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Realized gain (loss), investment and derivative	$ 289,228
Fair Value Adjustment of Commodity Derivative Instruments		$ (52,204)	$ (52,204)
Coal Contract
Derivative Instruments, Gain (Loss) [Line Items]
Fair Value Adjustment of Commodity Derivative Instruments	$ 52,204	$ (52,204)

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.

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Amount, before tax, of realized gain (loss) on investment and derivative, classified as operating. Investment includes, but is not limited to, debt and equity securities, security sold short, real estate, and commodity.

+ References

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The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of open derivatives, commodity, or energy contracts, held at each balance sheet date, that was included in earnings for the period.

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