Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net loss			$ (2,424)	$ (1,533)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	$ 264	$ 130	560	318
Accretion of asset retirement obligation			103	97
Gain on trading securities			(104)
Asset write off			7
Gain on reduction of asset retirement obligation				(56)
Gain on sale of assets			(1,335)	(596)
Warrant liability fair market adjustment				400	$ (17,100)
Stock compensation			250	307
Changes in operating assets and liabilities:
Increase (decrease) in trade accounts receivable			(121)	525
Decrease (increase) decrease in prepaid expenses and other assets			175	(47)
Decrease (increase) in inventories			3	(36)
Decrease (increase) in value added tax recoverable, net			127	(187)
Decrease in deferred revenue			(147)
Decrease in reclamation liability			(17)	(3)
Decrease in accounts payable and accrued liabilities			(9)	(47)
Decrease in deferred leasehold payments			(17)	(11)
Net cash used in operating activities			$ (2,949)	$ (1,269)