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Convertible Debt, Royalty and Production Payment Arrangements (Details) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
	Apr. 01, 2025 USD ($) PerTonne Tonnes	Jun. 30, 2025 USD ($) $ / shares	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) $ / shares	Jun. 30, 2024 USD ($)	Mar. 31, 2025 USD ($)
Gain Contingencies [Line Items]
Transaction cost		$ 13,337	$ 1,316	$ 17,639	$ 2,181
Orion Resource Partners LP (Orion) [Member]
Gain Contingencies [Line Items]
Investments	$ 217,075
Aggregate principal amount	195,000
Amount of initial investment	220,000
Issuance discount	2,925
Embedded Derivative [Member]
Gain Contingencies [Line Items]
Proceeds of transaction costs				4,379
Delayed Draw Notes [Member] \| Orion Resource Partners LP (Orion) [Member]
Gain Contingencies [Line Items]
Additional commitment amount	$ 30,000
Long-Term debt, term	2 years
Convertible Debt [Member]
Gain Contingencies [Line Items]
Aggregate principal amount		$ 199,815		$ 199,815		$ 195,000
Initial conversion price \| $ / shares		$ 3.78		$ 3.78
Interest rate on convertible debt		9.875%		9.875%
Maturity date				Apr. 01, 2030
Proceeds of transaction costs				$ 4,274
Effective interest		26.20%		26.20%
Convertible Debt [Member] \| Orion Resource Partners LP (Orion) [Member]
Gain Contingencies [Line Items]
Transaction cost				$ 9,700
PPA [Member]
Gain Contingencies [Line Items]
Proceeds of transaction costs				$ 1,047
Effective interest		29.00%		29.00%
Fixed payments received \| PerTonne	0.128
Percentage of additional variable payments recieved on total gross revenue	0.96%
Fixed and variable payments recieved \| Tonnes	41,500
PPA [Member] \| Delayed Draw Notes [Member]
Gain Contingencies [Line Items]
Fixed payments received \| PerTonne	0.152
Percentage of additional variable payments recieved on total gross revenue	1.14%
Phase 1 of Thacker Pass [Member] \| Orion Resource Partners LP (Orion) [Member]
Gain Contingencies [Line Items]
Investments	$ 250,000
Thacker Pass [Member] \| Orion Resource Partners LP (Orion) [Member]
Gain Contingencies [Line Items]
Amount paid for exchange	$ 25,000
Thacker Pass [Member]
Gain Contingencies [Line Items]
Obligated to gross revenue royalty		8.00%		8.00%
Mineral claims				$ 22,000
Rate of royalty				4.00%
Option at any time to reduce rate of royalty				1.75%