ASSET RETIREMENT AND ENVIRONMENTAL RECLAMATION OBLIGATIONS - Summary (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Asset Retirement Obligation and Accrual for Environmental Loss Contingencies [Roll Forward]
Obligations at beginning of period	$ 217,201
Liabilities incurred	3,456
Liabilities settled	(2,628)
Accretion expense	5,669
Change in estimate	12,634
Total obligations at end of period	236,332
Less current obligations at end of period	(16,337)
Long-term obligations at end of period	$ 219,995	$ 195,566