UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Revenues – Note 15		$ 0	$ 8,758	$ 0	$ 21,755
Cost of sales:
Production costs		0	8,803	0	22,020
Depreciation and amortization – Note 2		0	1,025	0	2,577
Mine site period costs – Note 2		0	1,409	0	10,429
Total cost of sales		0	11,237	0	35,026
Operating expenses:
Projects, exploration, and development		7,200	7,011	15,974	8,200
General and administrative		2,765	3,032	9,810	11,352
Mine site period costs – Note 2		2,694	0	9,325	0
Gain on settlement of accrued liability – Note 8		0	0	(1,151)	0
Depreciation and amortization – Note 2		726	0	2,155	0
Accretion – Note 12		186	102	558	306
Loss from operations		(13,571)	(12,624)	(36,671)	(33,129)
Other (expense) income:
Interest expense – Note 9		(4,698)	(4,459)	(13,721)	(14,003)
Interest income		2,100	826	6,159	846
Fair value adjustment to warrants – Notes 13 and 20		1	1,133	182	(482)
Gain (loss) on sale of equipment and supplies inventories, net of commissions	[1]	456	(725)	541	(123)
Net loss		$ (15,712)	$ (15,849)	$ (43,510)	$ (46,891)
Loss per share:
Basic (in dollars per share)		$ (0.08)	$ (0.08)	$ (0.22)	$ (0.29)
Diluted (in dollars per share)		$ (0.08)	$ (0.08)	$ (0.22)	$ (0.29)
Weighted average shares outstanding:
Basic (in shares)		201,954,021	199,207,092	201,021,368	159,607,217
Diluted (in shares)		201,954,021	199,207,092	201,021,368	159,607,217

[1] Certain items from prior years were reclassified in the financial statements to conform with the current year presentation.