Revenue From Contracts With Customers - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	$ 654,023	$ 604,916	$ 1,331,620	$ 1,141,086
Coal
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	541,099	532,726	1,124,478	1,009,110
Power Generation
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	240,546	256,731	541,057	570,428
Industrial
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	217,293	141,702	409,411	271,455
Metallurgical
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	83,260	134,293	174,010	167,227
Terminal Revenue
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	31,368	21,779	58,079	43,176
Freight Revenue
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	81,556	50,411	149,063	88,800
Domestic | Coal
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	141,311	212,702	336,820	438,150
Domestic | Power Generation
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	122,779	203,853	307,455	427,356
Domestic | Industrial
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	12,230	8,849	18,738	10,794
Domestic | Metallurgical
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	6,302	0	10,627	0
Export | Coal
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	399,788	320,024	787,658	570,960
Export | Power Generation
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	117,767	52,878	233,602	143,072
Export | Industrial
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	205,063	132,853	390,673	260,661
Export | Metallurgical
Disaggregation of Revenue [Line Items]
Total Revenue from Contracts with Customers	$ 76,958	$ 134,293	$ 163,383	$ 167,227