Restatement of Previously Issued Audited Financial Statements - Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	$ (136,392)	$ (98,895)
Adjustments to reconcile net loss for the period to net cash used in operating activities:
Non-cash portion of interest expense - Note 10	38,843	54,810
Write-down of production inventories - Note 4	17,924	18,617
Impairment on equipment not in use - Note 5	5,331	63
Depreciation and amortization	5,886	2,078
Stock-based compensation - Note 15	2,380	1,102
Salary continuation and compensation costs	2,116	0
Fair value adjustment to Seller Warrants - Note 19	3,767	0
Accretion - Note 12	374	422
Phantom share compensation	225	706
Amortization reduction of Sprott Royalty Obligation - Note 10	(37)	0
Reduction in asset retirement obligation	0	(1,880)
Change in value of phantom shares	0	181
Changes in operating assets and liabilities	(50,925)
Net cash used in operating activities	(110,508)	(59,771)
Net cash used in investing activities	(31,124)	(12,296)
Cash flows from financing activities:	188,705	68,173
Net increase (decrease) in cash and restricted cash	47,073	(3,894)
Cash and restricted cash, end of period	96,040	48,967
Cash and restricted cash, beginning of period	48,967	52,861
Total cash and restricted cash	96,040	48,967
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	(132,670)
Adjustments to reconcile net loss for the period to net cash used in operating activities:
Non-cash portion of interest expense - Note 10	38,843
Write-down of production inventories - Note 4	17,924
Impairment on equipment not in use - Note 5	5,331
Depreciation and amortization	5,886
Stock-based compensation - Note 15	2,380
Salary continuation and compensation costs	2,116
Fair value adjustment to Seller Warrants - Note 19	45
Accretion - Note 12	374
Phantom share compensation	225
Amortization reduction of Sprott Royalty Obligation - Note 10	(37)
Reduction in asset retirement obligation	0
Change in value of phantom shares	0
Changes in operating assets and liabilities	(50,925)
Net cash used in operating activities	(110,508)
Net cash used in investing activities	(31,124)
Cash flows from financing activities:	188,705
Net increase (decrease) in cash and restricted cash	47,073
Cash and restricted cash, end of period	96,040	48,967
Cash and restricted cash, beginning of period	48,967
Total cash and restricted cash	96,040	48,967
Restatement Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	(3,722)
Adjustments to reconcile net loss for the period to net cash used in operating activities:
Non-cash portion of interest expense - Note 10	0
Write-down of production inventories - Note 4	0
Impairment on equipment not in use - Note 5	0
Depreciation and amortization	0
Stock-based compensation - Note 15	0
Salary continuation and compensation costs	0
Fair value adjustment to Seller Warrants - Note 19	3,722
Accretion - Note 12	0
Phantom share compensation	0
Amortization reduction of Sprott Royalty Obligation - Note 10	0
Reduction in asset retirement obligation	0
Change in value of phantom shares	0
Changes in operating assets and liabilities	0
Net cash used in operating activities	0
Net cash used in investing activities	0
Cash flows from financing activities:	0
Net increase (decrease) in cash and restricted cash	0
Cash and restricted cash, end of period	0	0
Cash and restricted cash, beginning of period	0
Total cash and restricted cash	$ 0	$ 0