Note 11 - Commitments, Contingencies and Obligations (Details Textual) - USD ($) $ in Thousands			1 Months Ended			3 Months Ended
	Dec. 14, 2023	Jul. 12, 2022	Jul. 31, 2018	Aug. 31, 2012	Jun. 30, 2011	Mar. 31, 2024	Mar. 31, 2023
Loss Contingencies [Line Items]
Environmental remediation expense						$ 986	$ 1,044
Finance lease, liability, to be paid						26,389
Lessee, operating lease, liability, to be paid						13,475
Lease Commitments [Member]
Loss Contingencies [Line Items]
Lessee, operating lease, liability, to be paid						13,500
Performance Obligation Commitments [Member]
Loss Contingencies [Line Items]
Surety Bonds						195,300
Letters of credit outstanding, amount						6,800
Greens Creek [Member]
Loss Contingencies [Line Items]
Contractual obligation						26,400
Greens Creek [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation						11,100
Lucky Friday [Member]
Loss Contingencies [Line Items]
EPA maximum for statutory penalties, per day/violation		$ 59,973
EPA maximum for administrative penalties, per day/violation		23,989
EPA maximum for administrative penalties		$ 299,989
Lucky Friday [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation						17,500
Keno Hill [Member]
Loss Contingencies [Line Items]
Maximum Offense Fine	$ 100,000
Keno Hill [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation						10,200
Casa Berardi [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation						2,500
Nevada Operations [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation						800
Johnny M Mine Area near San Mateo, New Mexico [Member]
Loss Contingencies [Line Items]
Payment of response costs				$ 1,100
Estimated response costs			$ 9,600
Environmental remediation expense				10,100
Johnny M Mine Area near San Mateo, New Mexico [Member] | Environmental Remediation Past Response Costs [Member]
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies, period increase (decrease)				$ 10,100		$ 10,100
Carpenter Snow Creek Superfund Site, Cascade County, Montana [Member]
Loss Contingencies [Line Items]
Estimated response costs					$ 4,500
Estimated future response cost					$ 100,000