Long-term Debt - Schedule of Long-term Debt Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Apr. 30, 2021	Dec. 31, 2018
Debt Instrument [Line Items]
Long-term debt, gross	$ 185,206
Less: Unamortized Debt Issuance Costs	(1,686)	$ (3,721)
Principal amount	183,520	346,851
Less: amounts due in one year	(1,635)	(4,741)
Long-Term Debt	181,885	342,110
MEDCO Revenue Bonds in Series Due September 2025 at 5.75%
Debt Instrument [Line Items]
Long-term debt, gross	$ 102,865	$ 102,865
Stated interest rate percentage	5.75%	5.75%
PEDFA Solid Waste Disposal Revenue Bonds
Debt Instrument [Line Items]
Long-term debt, gross	$ 75,000	$ 75,000
Stated interest rate percentage	9.00%		900.00%
Advance Royalty Commitments
Debt Instrument [Line Items]
Long-term debt, gross	$ 5,922	$ 7,716
Weighted average interest rate	8.80%	8.09%
Other Asset Backed Financing
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,419	$ 2,400
Loans Payable | Revolving Credit Facility
Debt Instrument [Line Items]
Current portion of finance lease obligations	9,471	24,105
Loans Payable | Term Loan B Facility
Debt Instrument [Line Items]
Long-term debt, gross	0	63,484
Less: Unamortized Debt Issuance Costs		(106)
Principal amount		$ 63,590
Weighted average interest rate		8.92%
Senior Notes | Senior Secured Second Lien Notes due 2025
Debt Instrument [Line Items]
Long-term debt, gross	$ 0	$ 99,107
Stated interest rate percentage	11.00%	11.00%		11.00%