RECLAMATION AND REMEDIATION LIABILITIES - Reclamation and Remediation Costs (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Asset Retirement Obligation [Line Items]
Reclamation accretion			$ 11,190	$ 4,829
Total reclamation and remediation costs	$ 69,850	$ 2,414	74,170	277,732
Total reclamation costs
Asset Retirement Obligation [Line Items]
Reclamation adjustments and other	9,419	0	9,419	11,229
Reclamation accretion	6,874	2,414	11,190	4,829
Total reclamation and remediation costs	16,293	2,414	20,609	16,058
Total remediation costs
Asset Retirement Obligation [Line Items]
Reclamation adjustments and other	53,557	0	53,561	261,674
Reclamation accretion			0	0
Total reclamation and remediation costs	$ 53,557	$ 0	$ 53,561	$ 261,674