Revenue From Contracts With Customers - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	$ 490,720	$ 654,023	$ 1,037,409	$ 1,331,620
Coal
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	409,322	541,099	857,249	1,124,478
Power Generation
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	218,669	240,546	444,376	541,057
Industrial
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	129,975	217,293	282,741	409,411
Metallurgical
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	60,678	83,260	130,132	174,010
Terminal Revenue
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	12,020	31,368	36,548	58,079
Freight Revenue
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	65,640	81,556	135,482	149,063
Other Revenue
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	3,738		8,130
Domestic | Coal
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	204,167	141,311	385,563	336,820
Domestic | Power Generation
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	186,657	122,779	351,390	307,455
Domestic | Industrial
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	7,745	12,230	11,151	18,738
Domestic | Metallurgical
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	9,765	6,302	23,022	10,627
Export | Coal
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	205,155	399,788	471,686	787,658
Export | Power Generation
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	32,012	117,767	92,986	233,602
Export | Industrial
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	122,230	205,063	271,590	390,673
Export | Metallurgical
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	$ 50,913	$ 76,958	$ 107,110	$ 163,383