CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Cash flows used in operating activities:
Net loss	$ (23,213)	$ (32,278)	$ (41,328)	$ (117,608)
Adjustments to reconcile net loss for the period to net cash used in operating activities:
Non-cash portion of interest expense - Note 9			13,042	34,696
Non-cash (gain) loss on fair value adjustment for warrant liabilities - Note 11	(812)	3,354	(10,956)	4,276
Depreciation and amortization			5,175	4,250
Stock-based compensation - Note 14			2,227	1,991
Write-off of deposit	916	0	916	0
Accretion - Note 12	102	93	306	280
Write-down of production inventories - Note 4			0	17,924
Impairment on equipment not in use - Note 5	0	5,331	0	5,331
Phantom share compensation			0	225
Changes in operating assets and liabilities:
Accounts receivable			79	(500)
Income tax receivable			(95)	0
Production-related inventories			5,351	(39,763)
Materials and supplies inventories			(1,141)	(2,094)
Prepaids and other assets, net			(1,634)	(2,765)
Accounts payable and accrued expenses			(1,852)	6,926
Deferred revenue			1,598	0
Other liabilities			1,262	1,619
Net cash used in operating activities			(27,050)	(85,212)
Cash flows used in investing activities:
Additions to plant, equipment, and mine development			(11,908)	(19,237)
Net cash used in investing activities			(11,908)	(19,237)
Cash flows (used in) provided by financing activities:
Principal payments on debt			(2,978)	0
Principal payments on capital leases			(58)	0
Proceeds from sale of royalty to Sprott - Note 10			0	30,000
Proceeds from Recapitalization Transaction			0	10,419
Transaction and issuance costs			0	(15,801)
Net cash (used in) provided by financing activities			(3,036)	106,641
Net (decrease) increase in cash and restricted cash			(41,994)	2,192
Cash and restricted cash, beginning of period			96,040	48,967
Cash and restricted cash, end of period	54,046	51,159	54,046	51,159
Reconciliation of cash and restricted cash:
Cash	19,753	11,505	19,753	11,505
Restricted cash	34,293	39,654	34,293	39,654
Total cash and restricted cash	$ 54,046	$ 51,159	54,046	51,159
Sprott Credit Agreement
Proceeds from issuance of debt			0	68,600
The 1.25 Lien Notes
Proceeds from issuance of debt			0	44,841
First Lien Agreement
Repayment of debt			0	(125,468)
Promissory Note
Repayment of debt			0	(6,914)
Private Placement
Proceeds from issuance of equity			0	75,963
Forward purchase contract
Proceeds from issuance of equity			$ 0	$ 25,000