Note 2 - Business Segments and Sales of Products - Information About Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2025		Jun. 30, 2024		Jun. 30, 2025		Jun. 30, 2024		Dec. 31, 2024
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	$ 304,027		$ 245,657		$ 565,366		$ 435,185
Salaries, wages and other benefits	52,351		51,311		105,100		99,747
Contractors	27,139		20,909		53,054		38,911
Materials And Consumables	59,147		51,678		116,906		108,897
Product inventory change	(7,677)		(1,028)		(16,817)		(12,824)
Other direct production costs	16,384		19,357		38,051		39,828
Transfer to ramp-up and suspension costs			(1,763)	[1]			(12,634)	[2]
Depreciation, depletion and amortization	37,159		53,763		75,544		102,670
Gross profit	119,524		51,430		193,528		70,590
Other operating expenses	25,768	[3]	10,830	[4]	47,417	[5]	24,926	[6]
Income from operations	93,756		40,600		146,111		45,664
Interest expense	(11,099)		(12,505)		(22,650)		(25,149)
Fair value adjustments, net	9,615		5,002		13,242		3,150
Net foreign exchange (loss) gain	(3,517)		2,673		(3,873)		6,655
Other income	1,511		1,180		2,453		2,692
Income before income and mining taxes	90,266		36,950		135,283		33,012
Capital additions	58,043		50,420		112,138		98,009
Identifiable assets	3,309,355				3,309,355				$ 2,981,060
MetalSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	297,431		242,303		551,682		427,384
EnvironmentalRemediationServices [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	6,596		3,354		13,684		7,801
IntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	1,201		1,140		2,187		1,461
ReconciliationOfSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	305,228		246,797		567,553		436,646
EliminationOfIntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	(1,201)		(1,140)		(2,187)		(1,461)
Greens Creek [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Salaries, wages and other benefits	18,281		17,675		36,534		34,982
Contractors	1,557		1,782		2,462		3,431
Materials And Consumables	25,400		20,465		51,065		46,918
Product inventory change	(9,234)		(2,904)		(8,333)		(5,100)
Other direct production costs	10,020		8,453		20,345		20,654
Transfer to ramp-up and suspension costs			0	[1]			0	[2]
Depreciation, depletion and amortization	12,897		11,316		26,486		25,759
Gross profit	63,081		38,872		111,586		66,325
Capital additions	8,397		11,704		19,156		20,531
Identifiable assets	567,581				567,581				564,334
Greens Creek [Member] | MetalSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	122,002		95,659		240,145		192,969
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	122,002		95,659		240,145		192,969
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	14,559		13,155		29,335		24,737
Contractors	3,828		3,156		7,691		5,959
Materials And Consumables	10,899		8,735		22,322		18,903
Product inventory change	(476)		219		706		(1,882)
Other direct production costs	201		1,552		(419)		907
Transfer to ramp-up and suspension costs			0	[1]			(2,200)	[2]
Depreciation, depletion and amortization	13,275		10,707		26,700		18,619
Gross profit	21,987		21,547		41,132		29,368
Capital additions	15,942		10,818		31,388		25,806
Identifiable assets	619,273				619,273				587,945
Lucky Friday [Member] | MetalSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	64,273		59,071		127,467		94,411
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	64,273		59,071		127,467		94,411
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	7,209		7,831		13,681		14,567
Contractors	3,886		5,971		7,437		10,709
Materials And Consumables	8,050		7,239		14,044		14,825
Product inventory change	1,968		1,107		(5,994)		(4,653)
Other direct production costs	(373)		3,836		4,641		6,452
Transfer to ramp-up and suspension costs			(1,763)	[1]			(10,434)	[2]
Depreciation, depletion and amortization	5,141		4,730		7,943		8,331
Gross profit	240		0		1,278		0
Capital additions	17,045		14,533		27,481		24,879
Identifiable assets	426,580				426,580				413,982
Keno Hill [Member] | MetalSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	26,121		28,951		43,030		39,797
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	1,201		1,140		2,187		1,461
Keno Hill [Member] | ReconciliationOfSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	27,322		30,091		45,217		41,258
Keno Hill [Member] | EliminationOfIntersegmentSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	(1,201)		(1,140)		(2,187)		(1,461)
Casa Berardi [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Salaries, wages and other benefits	12,164		12,607		25,354		25,351
Contractors	11,449		6,827		22,114		12,050
Materials And Consumables	14,730		14,900		29,301		27,727
Product inventory change	65		550		(3,196)		(1,189)
Other direct production costs	6,536		5,445		13,484		11,700
Transfer to ramp-up and suspension costs			0	[1]			0	[2]
Depreciation, depletion and amortization	5,846		27,010		14,415		49,961
Gross profit	34,245		(8,717)		39,568		(25,393)
Capital additions	15,367		12,376		31,624		25,692
Identifiable assets	701,178				701,178				687,080
Casa Berardi [Member] | MetalSales [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Total sales	85,035		58,622		141,040		100,207
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	85,035		58,622		141,040		100,207
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	138		43		196		110
Contractors	6,419		3,173		13,350		6,762
Materials And Consumables	68		339		174		524
Product inventory change			0		0		0
Other direct production costs			71		0		115
Transfer to ramp-up and suspension costs			0	[1]			0	[2]
Depreciation, depletion and amortization			0		0		0
Gross profit	(29)		(272)		(36)		290
Capital additions	1,292		989		2,489		1,101
Identifiable assets	994,743				994,743				$ 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	6,596		3,354		13,684		7,801
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	6,596		3,354		13,684		7,801
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, and other operating (income) expense, net.