Property, Plant and Equipment, Net (Details)			1 Months Ended				3 Months Ended		6 Months Ended
	May 02, 2017 USD ($)	Mar. 31, 2017 USD ($)	May 31, 2017 USD ($)	Oct. 31, 2016 USD ($)	Aug. 31, 2016 USD ($) item	Apr. 30, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Property, plant and equipment
Property, plant and equipment, gross									$ 34,163,000		$ 34,751,000
Less: Accumulated depreciation & amortization									(25,454,000)		(25,516,000)
Property, plant and equipment, net									8,709,000		9,235,000
Payments to acquire property								$ 20,000		$ 20,000
Proceeds from sale of assets									733,000	50,000
Related party receivable											643,000
Gain on sale of equipment									596,000	$ 45,000
Mineral properties
Property, plant and equipment
Property, plant and equipment, gross									9,352,000		9,352,000
Exploration properties
Property, plant and equipment
Property, plant and equipment, gross									2,518,000		2,518,000
Royalty properties
Property, plant and equipment
Property, plant and equipment, gross									200,000		200,000
Buildings
Property, plant and equipment
Property, plant and equipment, gross									4,221,000		4,386,000
Mining equipment and machinery
Property, plant and equipment
Property, plant and equipment, gross									16,055,000		16,351,000
Other furniture and equipment
Property, plant and equipment
Property, plant and equipment, gross									952,000		952,000
Asset retirement cost
Property, plant and equipment
Property, plant and equipment, gross									865,000		$ 992,000
Celaya | Electrum
Property, plant and equipment
Payments to acquire property							$ 200,000
Interest in joint venture							60.00%
Exploration expenditures in first three year of the agreement							$ 2,500,000
Exploration expenditures in second three year of the agreement							$ 2,500,000
Additional interest in joint venture (as a percent)							20.00%
Net profit interest							10.00%
Celaya | Electrum | Minimum
Property, plant and equipment
Earn-in obligation							$ 500,000
Celaya | Electrum | Maximum
Property, plant and equipment
Interest in joint venture							80.00%
Zacatecas Properties | Santacruz
Property, plant and equipment
Proceeds from sale of assets				$ 200,000
Zacatecas Properties | Santacruz | Sale, not discontinued operations
Property, plant and equipment
Proceeds from sale of assets			$ 300,000			$ 200,000
Total consideration						$ 1,500,000
Due six months after signing agreement									300,000
Due 12 months after signing agreement									500,000
Minera Inde | Sale, not discontinued operations | Sale of Equipment
Property, plant and equipment
Sale of mining equipments					$ 687,000
Proceeds from sale of assets	$ 750,000	$ 100,000
Net book value of disposals		$ 185,000
Sales price received (as a percent)					10.00%
Interest rate on receivable (as a percent)		10.00%			10.00%
Minera Inde | Velardena properties | Sale, not discontinued operations | Sale of Equipment
Property, plant and equipment
Number of haul trucks sold | item					2
Number of scoop trams sold | item					2
Sale of mining equipments					$ 687,000
Proceeds from sale of assets	$ 750,000	$ 100,000			$ 69,000
Net book value of disposals		$ 185,000
Sales price received (as a percent)					10.00%
Related party receivable					$ 618,000
Interest rate on receivable (as a percent)					10.00%
Other operating income | Velardena properties | Sale, not discontinued operations | Sale of Equipment
Property, plant and equipment
Gain on sale of equipment									$ 105,000