Plant And Equipment (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) item	Dec. 31, 2017 USD ($)
Property, Plant and Equipment [Line Items]
Cost	$ 11,030	$ 12,479
Accumulated depreciation	5,395	4,924
Net	5,635	7,555
Impairment charge	1,000
Immaterial calculation differences
Property, Plant and Equipment [Line Items]
Depreciation	695
Mt Todd, Australia
Property, Plant and Equipment [Line Items]
Cost	5,197	5,646
Accumulated depreciation	5,062	4,591
Net	135	1,055
Corporate, United States
Property, Plant and Equipment [Line Items]
Cost	333	333
Accumulated depreciation	333	333
Used mill equipment, Canada
Property, Plant and Equipment [Line Items]
Cost	5,500	6,500
Net	$ 5,500	$ 6,500
Number of months to be considered held-for-sale | item	12
Impairment charge	$ 1,000