Revenue From Contracts With Customers - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	$ 546,689	$ 677,597
Coal
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	447,927	583,379
Power Generation
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	225,707	300,511
Industrial
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	152,766	192,118
Metallurgical
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	69,454	90,750
Terminal Revenue
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	24,528	26,711
Freight Revenue
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	69,842	67,507
Other Revenue
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	4,392
Domestic | Coal
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	181,396	195,509
Domestic | Power Generation
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	164,733	184,676
Domestic | Industrial
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	3,406	6,508
Domestic | Metallurgical
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	13,257	4,325
Export | Coal
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	266,531	387,870
Export | Power Generation
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	60,974	115,835
Export | Industrial
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	149,360	185,610
Export | Metallurgical
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	$ 56,197	$ 86,425