Note 10 - Commitments, Contingencies and Obligations (Details Textual) - USD ($) $ in Thousands			1 Months Ended			3 Months Ended		6 Months Ended
	May 24, 2023	Jul. 12, 2022	Jul. 31, 2018	Aug. 31, 2012	Jun. 30, 2011	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Loss Contingencies [Line Items]
Environmental remediation expense						$ 3,111	$ 1,472	$ 4,155	$ 2,373
Finance lease, liability, to be paid						35,927		35,927
Lessee, operating lease, liability, to be paid						13,215		13,215
Lease Commitments [Member]
Loss Contingencies [Line Items]
Lessee, operating lease, liability, to be paid						13,200		13,200
Performance Obligation Commitments [Member]
Loss Contingencies [Line Items]
Surety Bonds						193,200		193,200
Letters of credit outstanding, amount						6,800		6,800
Greens Creek [Member]
Loss Contingencies [Line Items]
Terms of settlement included fine	$ 100
Contractual obligation						35,900		35,900
Greens Creek [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation						16,500		16,500
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						20,800		20,800
Casa Berardi [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation						3,500		3,500
Nevada Operations [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation						2,300		2,300
Keno Hill [Member] | Purchase Orders and Commitment [Member]
Loss Contingencies [Line Items]
Contractual obligation						$ 10,500		10,500
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
Johnny M Mine Area near San Mateo, New Mexico [Member] | Environmental Remediation Past Response Costs [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies, period increase (decrease)								10,100
Johnny M Mine Area near San Mateo, New Mexico [Member] | Environmental Remediation Past Response Costs [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies, period increase (decrease)								$ 1,100
Carpenter Snow Creek Superfund Site, Cascade County, Montana [Member]
Loss Contingencies [Line Items]
Estimated response costs					$ 4,500
Estimated future response cost					$ 100,000