Inventories, net (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Inventory [Line Items]
Total inventories, net	$ 200,574	$ 129,382
Coal revenues
Inventory [Line Items]
Raw coal	57,382	20,347
Saleable coal	91,474	81,240
Materials, supplies and other, net
Inventory [Line Items]
Materials, supplies and other, net	$ 51,718	$ 27,795