Segment Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) segment	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Segment Information
Number of reportable segments | segment			2
Revenue	$ 1,730	$ 1,692	$ 3,367	$ 3,336
Depreciation, depletion and amortization	264	130	560	318
Exploration, El Quevar, Velardena and Administrative Expense	2,636	1,891	5,357	3,949
Pre-tax (gain) loss	1,689	460	2,424	1,533
Total Assets	12,191	13,255	12,191	13,255	$ 13,077
Capital Expenditures	30		58
Minerals
Segment Information
Costs Applicable to Sales	525	548	$ 1,028	1,085
Velardena properties
Segment Information
Number of reportable segments | segment			1
Revenue	1,730	1,692	$ 3,367	3,336
Depreciation, depletion and amortization	170	35	373	126
Exploration, El Quevar, Velardena and Administrative Expense	605	381	1,193	738
Pre-tax (gain) loss	(443)	(877)	(723)	(1,651)
Total Assets	6,369	7,326	6,369	7,326
Capital Expenditures			28
Velardena properties | Minerals
Segment Information
Costs Applicable to Sales	525	548	1,028	1,085
Corporate, Exploration & Other
Segment Information
Depreciation, depletion and amortization	94	95	187	192
Exploration, El Quevar, Velardena and Administrative Expense	2,031	1,510	4,164	3,211
Pre-tax (gain) loss	2,132	1,337	3,147	3,184
Total Assets	5,822	$ 5,929	5,822	$ 5,929
Capital Expenditures	$ 30		$ 30