Note 1 - Basis of Preparation of Financial Statements (Details Textual) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2021 USD ($)	Dec. 31, 2020 USD ($) oz
Casa Berardi [Member]
Decrease in Expected Gold Production Due to Suspension (Ounce) | oz			11,700
Suspension Costs			$ 1.6
Pandemic Related Procedures Costs		$ 1.9
San Sebastian [Member]
Suspension Costs			1.8
Greens Creek [Member]
Suspension Costs from Quarantining Employee Per Week		$ 1.0	$ 2.3
Percentage of Increase (Decrease) in Silver Production	(30.00%)