Note 2 - Business Segments and Sales of Products - Information About Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2025		Sep. 30, 2024		Sep. 30, 2025		Sep. 30, 2024		Dec. 31, 2024
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	$ 409,542		$ 245,085		$ 974,908		$ 680,270
Salaries, wages and other benefits	56,520		52,419		161,620		152,166
Contractors	33,307		22,723		86,361		61,634
Materials And Consumables	58,522		48,885		175,428		157,782
Product inventory change	(16,329)		(5,530)		(488)		(7,294)
Other direct production costs	15,773		25,285		53,824		65,113
Transfer to ramp-up and suspension costs			(9,987)	[1]			(22,621)	[2]
Depreciation, depletion and amortization	48,624		40,944		124,168		143,614
Gross profit	180,467		59,286		373,995		129,876
Other operating expenses	31,822	[3]	36,811	[4]	79,239	[5]	61,737	[6]
Income from operations	148,645		22,475		294,756		68,139
Interest expense	(13,405)		(10,901)		(36,055)		(36,050)
Fair value adjustments, net	17,625		3,654		30,867		6,804
Net foreign exchange gain (loss)	305		(3,246)		(3,568)		3,409
Other income	2,433		1,229		4,886		3,921
Income before income and mining taxes	155,603		13,211		290,886		46,223
Capital additions	57,905		55,699		170,043		153,708
Identifiable assets	3,221,842				3,221,842				$ 2,981,060
MetalSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	393,351		237,757		945,033		665,141
EnvironmentalRemediationServices [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	16,191		7,328		29,875		15,129
IntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	1,928		1,495		4,115		2,956
ReconciliationOfSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	411,470		246,580		979,023		683,226
EliminationOfIntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	(1,928)		(1,495)		(4,115)		(2,956)
Greens Creek [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Salaries, wages and other benefits	19,392		18,098		55,926		53,080
Contractors	2,951		1,423		5,413		4,854
Materials And Consumables	27,430		21,101		78,495		68,019
Product inventory change	(5,106)		(8,125)		(3,227)		3,025
Other direct production costs	10,550		10,901		30,895		31,555
Transfer to ramp-up and suspension costs			0	[1]			0	[2]
Depreciation, depletion and amortization	16,229		13,948		42,715		39,707
Gross profit	96,406		42,972		207,992		109,297
Capital additions	12,179		11,466		31,335		31,997
Identifiable assets	580,967				580,967				564,334
Greens Creek [Member] | MetalSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	178,064		116,568		418,209		309,537
Greens Creek [Member] | EnvironmentalRemediationServices [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	0		0		0		0
Greens Creek [Member] | IntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	0		0		0		0
Greens Creek [Member] | ReconciliationOfSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	178,064		116,568		418,209		309,537
Greens Creek [Member] | EliminationOfIntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	0		0		0		0
Lucky Friday [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Salaries, wages and other benefits	16,586		14,218		45,921		38,955
Contractors	3,669		3,988		11,360		9,947
Materials And Consumables	11,398		10,411		33,720		29,314
Product inventory change	(1,127)		126		421		(2,008)
Other direct production costs	644		120		(225)		1,027
Transfer to ramp-up and suspension costs			7	[1]			(2,207)	[2]
Depreciation, depletion and amortization	13,471		10,681		40,171		29,300
Gross profit	29,551		11,787		70,683		41,155
Capital additions	16,865		11,178		48,253		36,984
Identifiable assets	641,202				641,202				587,945
Lucky Friday [Member] | MetalSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	74,192		51,072		201,659		145,483
Lucky Friday [Member] | EnvironmentalRemediationServices [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	0		0		0		0
Lucky Friday [Member] | IntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	0		0		0		0
Lucky Friday [Member] | ReconciliationOfSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	74,192		51,072		201,659		145,483
Lucky Friday [Member] | EliminationOfIntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	0		0		0		0
Keno Hill [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Salaries, wages and other benefits	7,377		7,567		21,058		22,134
Contractors	3,781		6,540		11,218		17,249
Materials And Consumables	5,913		6,472		19,957		21,297
Product inventory change	8,057		293		(2,063)		(4,946)
Other direct production costs	(1,985)		5,285		2,656		11,737
Transfer to ramp-up and suspension costs			(9,980)	[1]			(20,414)	[2]
Depreciation, depletion and amortization	8,028		4,218		15,971		12,549
Gross profit	16,380		0		17,658		0
Capital additions	14,747		14,406		42,228		39,285
Identifiable assets	447,999				447,999				413,982
Keno Hill [Member] | MetalSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	47,551		19,809		90,581		59,606
Keno Hill [Member] | EnvironmentalRemediationServices [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	0		0		0		0
Keno Hill [Member] | IntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	1,928		1,495		4,115		2,956
Keno Hill [Member] | ReconciliationOfSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	49,479		21,304		94,696		62,562
Keno Hill [Member] | EliminationOfIntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	(1,928)		(1,495)		(4,115)		(2,956)
Casa Berardi [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Salaries, wages and other benefits	12,988		12,485		38,342		37,836
Contractors	7,241		4,127		29,355		16,177
Materials And Consumables	13,444		10,846		42,745		38,573
Product inventory change	4,293		2,176		(1,097)		(3,365)
Other direct production costs	6,560		8,901		20,044		20,601
Transfer to ramp-up and suspension costs			0	[1]			0	[2]
Depreciation, depletion and amortization	10,896		12,097		25,311		62,058
Gross profit	38,122		(4,028)		77,690		(21,365)
Capital additions	13,480		18,606		45,104		44,298
Identifiable assets	712,177				712,177				687,080
Casa Berardi [Member] | MetalSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	93,544		50,308		234,584		150,515
Casa Berardi [Member] | EnvironmentalRemediationServices [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	0		0		0		0
Casa Berardi [Member] | IntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	0		0		0		0
Casa Berardi [Member] | ReconciliationOfSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	93,544		50,308		234,584		150,515
Casa Berardi [Member] | EliminationOfIntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	0		0		0		0
Other Operating Segment [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Salaries, wages and other benefits	177		51		373		161
Contractors	15,665		6,645		29,015		13,407
Materials And Consumables	337		55		511		579
Product inventory change			0		0		0
Other direct production costs			78		4		193
Transfer to ramp-up and suspension costs			0	[1]			0	[2]
Depreciation, depletion and amortization			0		0		0
Gross profit	(8)		(499)		(28)		789
Capital additions	634		43		3,123		1,144
Identifiable assets	839,497				839,497				$ 727,719
Other Operating Segment [Member] | MetalSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	0		0		0		0
Other Operating Segment [Member] | EnvironmentalRemediationServices [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	16,191		7,328		29,875		15,129
Other Operating Segment [Member] | IntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	0		0		0		0
Other Operating Segment [Member] | ReconciliationOfSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	16,191		7,328		29,875		15,129
Other Operating Segment [Member] | EliminationOfIntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	$ 0		$ 0		$ 0		$ 0

[1] Total cost of sales in excess of sales value are transferred to ramp-up and suspension costs.

[2] Total cost of sales in excess of sales value are transferred to ramp-up and suspension costs.

[3] Other operating expense items include general and administrative, exploration and pre-development, ramp-up and suspension costs, provision for closed operations and environmental matters, and other operating (income) expense, net.

[4] Other operating expense items include general and administrative, exploration and pre-development, ramp-up and suspension costs, provision for closed operations and environmental matters, and other operating (income) expense, net.

[5] Other operating expense items include general and administrative, exploration and pre-development, provision for closed operations and environmental matters, ramp-up and suspension costs and other operating (income) expense, net.

[6] Other operating expense items include general and administrative, exploration and pre-development, ramp-up and suspension costs, provision for closed operations and environmental matters, write down of property, plant and equipment and other operating (income) expense, net.