Concentration of Credit Risk and Major Customers - Schedule of Concentration of Credit Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Concentration Risk [Line Items]
Accounts receivables, before allowance for credit loss	$ 138,015	$ 148,078
Less: Allowance for credit losses	(1,265)	(466)
Total Trade Receivables, net	136,750	147,612
Accounts Receivable | Customer Concentration Risk | Electric coal utilities
Concentration Risk [Line Items]
Accounts receivables, before allowance for credit loss	30,162	28,870
Accounts Receivable | Customer Concentration Risk | Coal exporters and industrial customers
Concentration Risk [Line Items]
Accounts receivables, before allowance for credit loss	69,630	85,080
Accounts Receivable | Customer Concentration Risk | Steel and coke producers
Concentration Risk [Line Items]
Accounts receivables, before allowance for credit loss	33,126	29,340
Accounts Receivable | Customer Concentration Risk | Other
Concentration Risk [Line Items]
Accounts receivables, before allowance for credit loss	$ 5,097	$ 4,788