Note 14 - Properties, Plants, Equipment and Mineral Interests, and Lease Commitments (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Payments to Acquire Property, Plant, and Equipment, Total	$ 109,048	$ 91,016	$ 121,421
Finance Lease, Right-of-Use Asset, before Accumulated Amortization	78,900	74,000
Finance Lease, Right-of-Use Asset, Accumulated Amortization	60,600	51,700
Lucky Friday [Member]
Payments to Acquire Property, Plant, and Equipment, Total	29,885	25,776	8,989
Greens Creek [Member]
Payments to Acquire Property, Plant, and Equipment, Total	23,883	19,685	29,570
Mining Assets, Value Beyond Proven and Probable Reserves (VBPP)	132,600
Casa Berardi [Member]
Payments to Acquire Property, Plant, and Equipment, Total	49,617	40,840	36,059
Mining Assets, Value Beyond Proven and Probable Reserves (VBPP)	323,600
Nevada Operations [Member]
Payments to Acquire Property, Plant, and Equipment, Total	5,470	$ 4,003	$ 42,953
Mining Assets, Value Beyond Proven and Probable Reserves (VBPP)	$ 382,900