Derivatives - Schedule of Derivative Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Asset Derivatives
Effect of Counterparty Netting	$ (6,024)	$ (1,086)
Net derivative assets	0	0
Liability Derivatives
Effect of Counterparty Netting	6,024	1,086
Net derivative liabilities	(15,142)	(52,204)
Coal Contract
Asset Derivatives
Coal swap contract asset derivatives	6,024	1,086
Liability Derivatives
Coal swap contract liability derivatives	$ (21,166)	$ (53,290)

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