Mineral Properties - Guadalupe (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	9 Months Ended
	Jul. 31, 2020	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Mineral properties, Net		$ 2,146	$ 2,146	$ 2,146
Deferred option gain		68	68	$ 168
Gain (Loss) On Disposal Of Mineral Property Interests, Net		3,540	6,108
Guadalupe De Los Reyes, Mexico | Option Agreement Two
Property, Plant and Equipment [Line Items]
Sale price of gold/silver project	$ 1,500
Payments Received In Lieu Of Grant Of Royalty And Back-In Rights		2,100
Deferred option gain		2,892	$ 2,892
Gain (Loss) On Disposal Of Mineral Property Interests, Net		3,540
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-31 | Guadalupe De Los Reyes, Mexico | Option Agreement Two
Property, Plant and Equipment [Line Items]
Payments Received In Lieu Of Grant Of Royalty And Back-In Rights		1,100
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-31 | Guadalupe De Los Reyes, Mexico | Option Agreement Two
Property, Plant and Equipment [Line Items]
Payments Received In Lieu Of Grant Of Royalty And Back-In Rights		$ 1,000