CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Revenues - Note 14	$ 36,001,000	$ 7,636,000	$ 55,037,000	$ 18,760,000
Cost of sales:
Production costs	29,494,000	7,486,000	47,311,000	16,421,000
Depreciation and amortization	1,573,000	548,000	2,614,000	1,324,000
Mine site period costs - Note 4	2,434,000	12,870,000	12,978,000	20,062,000
Write-down of production inventories - Note 4	0	10,959,000	0	17,924,000
Total cost of sales	33,501,000	31,863,000	62,903,000	55,731,000
Operating expenses:
General and administrative	5,164,000	10,432,000	8,958,000	12,438,000
Projects and development	1,023,000	0	1,516,000	0
Accretion - Note 12	102,000	94,000	204,000	187,000
Loss from operations	(3,789,000)	(34,753,000)	(18,544,000)	(49,596,000)
Other (expense) income:
Interest expense, net of capitalized interest - Note 9	(5,298,000)	(15,072,000)	(9,747,000)	(34,959,000)
Fair value adjustment to warrants - Notes 11 and 18	651,000	(922,000)	10,144,000	(922,000)
Interest income	9,000	35,000	32,000	147,000
Loss before income taxes	(8,427,000)	(50,712,000)	(18,115,000)	(85,330,000)
Income taxes - Note 15	0	0	0	0
Net loss	$ (8,427,000)	$ (50,712,000)	$ (18,115,000)	$ (85,330,000)
Earnings Per Share [Abstract]
Basic (in dollars per share)	$ (0.14)	$ (2.76)	$ (0.30)	$ (9.12)
Diluted (in dollars per share)	$ (0.14)	$ (2.76)	$ (0.30)	$ (9.12)
Weighted average shares outstanding:
Basic (in shares)	59,927,523	18,395,983	59,914,487	9,359,655
Diluted (in shares)	59,927,523	18,395,983	59,914,487	9,359,655