Note 11 - Commitments, Contingencies and Obligations (Details Textual) - USD ($) $ in Thousands	1 Months Ended			3 Months Ended
	May 31, 2024	Jul. 31, 2018	Jun. 30, 2011	Mar. 31, 2025	Mar. 31, 2024
Loss Contingencies [Line Items]
Environmental remediation expense				$ 790	$ 986
Lessee, operating lease, liability, to be paid				12,730
Lease Commitments [Member]
Loss Contingencies [Line Items]
Lessee, operating lease, liability, to be paid				9,800
Performance Obligation Commitments [Member]
Loss Contingencies [Line Items]
Surety bonds				215,600
Letters of credit outstanding, amount				6,600
Canada Revenue Agency [Member]
Loss Contingencies [Line Items]
Payments for legal settlements	$ 32,000
Assessed sales tax	1,038,834
Notice Of Assessment [Member] | Canada Revenue Agency [Member]
Loss Contingencies [Line Items]
Assessed sales tax	$ 1,973,181
Greens Creek [Member]
Loss Contingencies [Line Items]
Contractual obligation				19,600
Greens Creek [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation				11,700
Lucky Friday [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation				7,600
Keno Hill [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation				11,100
Casa Berardi [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation				7,600
Other [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation				$ 1,900
Johnny M Mine Area near San Mateo, New Mexico [Member]
Loss Contingencies [Line Items]
Estimated response costs		$ 9,600
Carpenter Snow Creek Superfund Site, Cascade County, Montana [Member]
Loss Contingencies [Line Items]
Estimated response costs			$ 4,500
Estimated future response cost			$ 100,000