Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net loss			$ (5,659)	$ (4,809)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	$ 265	$ 270	544	544
Accretion of asset retirement obligation			121	111
Decrease in derivative at fair value			125
Loss (gain) on trading securities				158
Asset write off			100	19
Gain on sale of assets				(104)
Stock compensation			666	653
Changes in operating assets and liabilities from continuing operations:
Decrease (increase) in lease receivable			95	(29)
Increase (decrease) in prepaid expenses and other assets			(516)	144
Increase (decrease) in inventories			45	(2)
Increase in value added tax recoverable, net				(3)
Decrease (increase) in other long term assets			598	(465)
Decrease in reclamation liability			(2)	(63)
(Decrease) increase in accounts payable and accrued liabilities			(950)	130
(Decrease) increase in other current liabilities			(953)	1,689
Decrease in deferred revenue			(245)	(146)
(Decrease) increase in other long term liabilities			(82)	388
Net cash used in operating activities			$ (6,113)	$ (1,785)

The increase (decrease) during the reporting period in the aggregate value of plant lease receivables.

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