Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net loss			$ (3,988)	$ (5,659)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	$ 168	$ 265	323	544
Accretion of asset retirement obligation			131	121
Decrease (increase) in derivative at fair value, net				125
Gain on trading securities			(39)
Asset write off			(1)	100
Gain on sale of assets			(17)
Stock compensation			1,416	666
Changes in operating assets and liabilities from continuing operations:
Decrease in lease receivable				95
(Increase) decrease in prepaid expenses and other assets			112	(505)
(Increase) decrease in inventories			(1,681)	45
Decrease in value added tax recoverable, net			(1,555)	(11)
Decrease in other long-term assets			552	598
Decrease in reclamation liability			(33)	(2)
Increase (decrease) in accounts payable and accrued liabilities			1,322	(950)
Decrease in other current liabilities			(280)	(953)
Decrease in deferred revenue			(279)	(245)
Decrease in other long-term liabilities			(181)	(82)
Net cash used in operating activities			$ (4,198)	$ (6,113)