CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Income Statement [Abstract]
Revenues – Note 15		$ 0	$ 33,229
Cost of sales:
Production costs		0	30,756
Mine site period costs – Note 2			13,720
Asset retirement obligation adjustments – Notes 2 and 8		0	4,701
Depreciation and amortization – Note 2		0	3,361
Write-down of supplies inventories – Notes 2 and 4		0	1,051
Total cost of sales		0	53,589
Operating expenses:
Projects, exploration, and development		20,637	18,355
General and administrative		12,673	14,367
Mine site period costs – Note 2		11,886
Depreciation and amortization – Note 2		2,814	0
Accretion – Note 8		1,087	408
Write-down of supplies inventories – Notes 2 and 4		495	0
Gain on settlement of accrued liability		(1,151)	0
Asset retirement obligation adjustments – Notes 2 and 8		(2,887)	0
Loss from operations		(45,554)	(53,490)
Other (expense) income:
Interest expense – Note 9		(18,467)	(18,481)
Interest income		8,278	2,313
Gain on sale of assets, net of commissions		544	3,948
Fair value adjustment to warrants – Notes 14 and 21		175	(159)
Gain on extinguishment of debt – Note 9		0	5,041
Net loss		$ (55,024)	$ (60,828)
Loss per share
Basic (in USD per share)	[1]	$ (2.61)	$ (3.58)
Diluted (in USD per share)	[1]	$ (2.61)	$ (3.58)
Weighted average shares outstanding
Basic (in shares)	[1]	21,113,516	16,977,306
Diluted (in shares)	[1]	21,113,516	16,977,306

[1] On November 14, 2023, the Company effectuated a reverse stock split with a ratio of 1-for-10. All share and per share information has been retroactively adjusted to give effect to the reverse stock split for all periods presented.