Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) segment	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Segment Information
Number of reportable segments | segment			2
Revenue	$ 1,900	$ 1,771	$ 5,267	$ 5,107
Depreciation, depletion and amortization	337	138	897	456
Exploration, El Quevar, Velardena and Administrative Expense	2,542	2,232	7,899	6,181
Pre-tax (gain) loss	(1,585)	318	839	1,851
Total Assets	14,229	14,902	14,229	14,902	$ 13,077
Capital Expenditures	3	5	61	5
Minerals
Segment Information
Costs Applicable to Sales	657	619	$ 1,685	1,704
Velardena properties
Segment Information
Number of reportable segments | segment			1
Revenue	1,900	1,771	$ 5,267	5,107
Depreciation, depletion and amortization	243	53	616	179
Exploration, El Quevar, Velardena and Administrative Expense	561	623	1,754	1,361
Pre-tax (gain) loss	(311)	(2,016)	(1,034)	(3,667)
Total Assets	6,084	6,573	6,084	6,573
Capital Expenditures	3	3	31	3
Velardena properties | Minerals
Segment Information
Costs Applicable to Sales	657	619	1,685	1,704
Corporate, Exploration & Other
Segment Information
Depreciation, depletion and amortization	94	85	281	277
Exploration, El Quevar, Velardena and Administrative Expense	1,981	1,609	6,145	4,820
Pre-tax (gain) loss	(1,274)	2,334	1,873	5,518
Total Assets	$ 8,145	8,329	8,145	8,329
Capital Expenditures		$ 2	$ 30	$ 2