Liquidity (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
	Jun. 26, 2019	Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2020	Dec. 31, 2018	Dec. 31, 2017
Cash and cash equivalents		$ 2,892	$ 4,996		$ 2,892	$ 4,996		$ 3,293	$ 3,250
Increase in cash inflows					8,400
Cash Resources					8,700
Shutdown and care and maintenance costs		422	428		1,391	1,409
Payments to acquire property		1	3		28	61
General and administrative expenses		742	$ 673		2,784	2,556
Income tax payments due		$ 274			274			$ 267
Net proceeds from the sale of the Company’s common stock					2,492	$ 809
Other exploration and property holding costs					8,800
Reduction in working capital					$ 200
Period Of Future Operation					1 year
Forecast
Project expenditures							$ 9,800
Forecast | Canada
Income tax payments due							300
Velardena properties
Shutdown and care and maintenance costs					$ 1,300
Other exploration and property holding costs					1,500
Oxide Plant
Net operating margin					4,000
El Quevar Project
Payments to acquire property					1,000
Other exploration and property holding costs					1,600
El Quevar Project | Forecast
Maintenance and property holding costs							800
LPC Program
Other exploration and property holding costs					600
LPC Program | Forecast
General and administrative expenses							3,100
Santa Maria property | Forecast
Net operating margin							4,800
Sale of an investment				$ 1,000
Yoquivo and other properties | Forecast
Other exploration and property holding costs							2,500
IPO
Net proceeds from the sale of the Company’s common stock					1,900
Golden Tag
Sale of miscellaneous assets					100
Sale of an investment					$ 100
Electrum | Velardena properties | Forecast
Shutdown and care and maintenance costs							1,600
Autlan | Agreement
Payments to acquire property	$ 1,500
Autlan | Agreement | Forecast
Payments to acquire property							$ 1,500