Debt (Details Textual) - USD ($) shares in Thousands, $ in Thousands						1 Months Ended		3 Months Ended	4 Months Ended	11 Months Ended	12 Months Ended
	Jan. 01, 2025	Feb. 21, 2024	Nov. 09, 2022	May 02, 2022	Mar. 01, 2021	Mar. 31, 2021	Oct. 31, 2018	Sep. 30, 2024	Dec. 31, 2024	Jun. 30, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Dec. 14, 2020	Dec. 13, 2020	Sep. 30, 2017
Debt Instrument [Line Items]
Gain on debt extinguishment											$ 3,437	$ 0	$ (9,173)
Financing cash flows from finance leases											24,505	31,316	$ 31,544
Finance Lease Obligations											$ 35,200
Rochester Finance Lease | Line of Credit
Debt Instrument [Line Items]
Debt Instrument, Face Amount												$ 60,000
Stated interest rate											5.20%
Senior Notes due 2029
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 375,000
Proceeds from debt						$ 367,500
Extinguishment of debt											$ 76,000
Converted shares (in shares)											25,200
Gain on debt extinguishment											$ 3,400
Senior Notes due Two Thousand Twenty Four
Debt Instrument [Line Items]
Stated interest rate											5.125%
Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity					$ 300,000		$ 250,000							$ 200,000	$ 300,000	$ 250,000	$ 200,000
Line of credit facility					$ 100,000		$ 50,000
Integration costs			$ 50,000
Cash on hand			$ 60,000
Letters of credit outstanding, amount											$ 29,600
Revolving Credit Facility | Subsequent Event
Debt Instrument [Line Items]
Additional increases in RCF		$ 100,000
Non-capitalized underground mine development costs		15,000
Line of credit facility		10,000
Revolving Credit Facility | Forecast
Debt Instrument [Line Items]
Interest coverage ratio	$ 15,000							$ 40,000	$ 30,000	$ 50,000
Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Stated interest rate											9.20%
Long-term debt											$ 175,000
Amount available subject to debt covenants											$ 185,400
Revolving Credit Facility | Credit Agreement | Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 390,000
Line of credit facility				$ 300,000
Revolving Credit Facility | Credit Agreement | Line of Credit | Subsequent Event
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 400,000
Minimum | Revolving Credit Facility | Base Rate [Member]
Debt Instrument [Line Items]
Basis rate											1.00%
Minimum | Revolving Credit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis rate											2.00%
Maximum | Revolving Credit Facility | Base Rate [Member]
Debt Instrument [Line Items]
Basis rate											1.75%
Maximum | Revolving Credit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis rate											2.75%