Segment Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($) segment	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Segment Information
Number of reportable segments | segment	2
Revenue	$ 1,932	$ 1,637
Mineral Extraction Processing and Marketing Costs	597	503
Depreciation, depletion and amortization	274	296
Exploration, El Quevar, Velardena and Administrative Expense	2,760	2,721
Pre-tax (gain) loss	2,351	735
Total Assets	11,288	12,334	$ 12,644
Capital Expenditures	$ 25	28
Velardena properties
Segment Information
Number of reportable segments | segment	1
Revenue	$ 1,932	1,637
Mineral Extraction Processing and Marketing Costs	597	503
Depreciation, depletion and amortization	202	203
Exploration, El Quevar, Velardena and Administrative Expense	634	588
Pre-tax (gain) loss	(316)	(217)
Total Assets	5,641	6,661
Capital Expenditures		28
Corporate, Exploration & Other
Segment Information
Depreciation, depletion and amortization	72	93
Exploration, El Quevar, Velardena and Administrative Expense	2,126	2,133
Pre-tax (gain) loss	2,667	952
Total Assets	5,647	$ 5,673
Capital Expenditures	$ 25