Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Statement of Cash Flows [Abstract]
Net loss for the period	$ (9,254)	$ (14,730)	$ (7,957)	$ (10,910)	$ (42,043)	$ (29,658)
Items not involving cash:
Depletion, depreciation and amortization	850		800		2,529	2,363
Share-based compensation					3,292	1,702
Change in value of warrant liabilities					0	8,050
Accretion of asset retirement obligation	397		350		1,301	1,022	$ 1,284
Unrealized foreign exchange (gain) loss					2,284	(440)
Revision and settlement of asset retirement obligation					(238)	(39)
Unrealized gain on available-for-sale assets					13,716	0
Other non-cash expenses (income)					297	(3,017)
Changes in assets and liabilities
(Increase) decrease in inventories					2,729	(1,673)
(Increase) decrease in trade and other receivables					565	(61)
Increase in prepaid expenses and other assets					(7,614)	(678)
Decrease in accounts payable and accrued liabilities					(1,703)	(434)
Net cash used in operating activities					(29,453)	(21,983)
INVESTING ACTIVITIES
Purchase of property, plant and equipment					1,237	953
Purchases of marketable securities					(11,435)	0
Maturities and sales of marketable securities					0	2,554
Net cash (used in) provided by investing activities					(12,672)	1,601
FINANCING ACTIVITIES
Issuance of common shares for cash, net of issuance cost					7,886	92,122
Cash paid to fund employee income tax withholding due upon vesting of restricted stock units					(884)	(659)
Cash received from exercise of stock options					472	1,718
Cash received from exercise of warrants					0	6,627
Cash paid to settle and fund employee income tax withholding due upon exercise of stock appreciation rights					(11)	(48)
Cash received from non-controlling interest					0	229
Net cash provided by financing activities					7,463	99,989
Effect of exchange rate fluctuations on cash held in foreign currencies					(84)	(61)
Net change in cash, cash equivalents and restricted cash					(34,746)	79,546
Cash, cash equivalents and restricted cash, beginning of period		$ 132,822		$ 40,985	132,822	40,985	40,985
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, END OF PERIOD	$ 98,076		$ 120,531		98,076	120,531	$ 132,822
Supplemental disclosure of cash flow information:
Increase (decrease) in accrued capital expenditures and accounts payable for property, plant and equipment					$ (116)	$ 0