Note 11 - Commitments, Contingencies and Obligations (Details Textual) - USD ($) $ in Thousands	1 Months Ended			3 Months Ended		6 Months Ended
	May 31, 2024	Jul. 31, 2018	Jun. 30, 2011	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Loss Contingencies [Line Items]
Environmental remediation expense				$ 844	$ 1,153	$ 1,634	$ 2,139
Lessee, operating lease, liability, to be paid				12,031		12,031
Lease Commitments [Member]
Loss Contingencies [Line Items]
Lessee, operating lease, liability, to be paid				12,000		12,000
Performance Obligation Commitments [Member]
Loss Contingencies [Line Items]
Surety bonds				218,900		218,900
Letters of credit outstanding, amount				6,700		6,700
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				19,700		19,700
Greens Creek [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation				12,300		12,300
Lucky Friday [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation				5,900		5,900
Keno Hill [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation				8,400		8,400
Casa Berardi [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation				10,400		10,400
Other [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation				$ 4,500		$ 4,500
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