INCOME AND MINING TAXES - Reconciliation of Tax Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income tax reconciliation
Income (loss) before income and mining taxes	$ 6,949	$ (46,739)	$ 67,036
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
U.S. Federal statutory tax rate	1,459	(9,815)	14,078
State and local income taxes, net of Federal income tax	1,296
Adjustment for foreign tax rate		(3,746)	(13,769)
Change in valuation allowance		(505)	821
Equity loss from investments		10,555	15,310
Deconsolidation of McEwen Copper Inc.			(46,644)
Disposal of McEwen Copper Inc.'s shares		(1,531)	6,179
Deferred tax liability on investment in associate			38,340
Realized flow-through expenditures		4,017	3,570
Realized flow-through premium		(2,304)	(3,423)
Withholding taxes		426	632
Permanent differences		(2,014)	9,909
Effect of foreign exchange on translation of books and records		(4,157)	42
Losses expired		3,330	8,282
Effect of changes in tax laws/rates enacted in the current period
Effect of cross-border tax laws	931
Tax credits	(74)
Nontaxable/nondeductible items
Non deductible expense	478
Changes in unrecognized tax benefits	695
Other adjustments
Adjustments in relation to prior years		367	(629)
Other		46	(294)
Current and deferred mining tax liabilities		2,283	1,455
(Loss) income and mining tax (recovery) expense	$ (27,485)	$ (3,048)	$ 33,859
Tax Jurisdiction of Domicile [Extensible Enumeration]	United States	United States	United States
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal statutory tax rate	21.00%	21.00%	21.00%
State and local income taxes, net of Federal income tax	19.00%
Adjustment for foreign tax rate	0.00%
Effect of changes in tax laws/rates enacted in the current period	0.00%
Effect of cross-border tax laws	13.00%
Tax credits	(1.00%)
Nontaxable/nondeductible items
Non deductible expense	7.00%
Changes in unrecognized tax benefits	10.00%
Other adjustments
Income and mining tax recovery	(396.00%)
United States
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Change in valuation allowance	$ (30,209)
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Change in valuation allowance	(435.00%)
Canada
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Adjustment for foreign tax rate	$ 2,562
Adjustment for foreign provincial tax rate	(4,640)
Change in valuation allowance	12,248
Branch losses	(10,127)
Equity loss from investments	3,280
Realized flow-through expenditures	5,483
Realized flow-through premium	(5,649)
Deferred mining tax expense net of income tax benefit	672
Withholding taxes	342
Effect of foreign exchange on translation of books and records	(537)
Nontaxable/nondeductible items
Non deductible expense	915
Other adjustments
Adjustments in relation to prior years	(585)
Other	$ (112)
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Adjustment for foreign tax rate	37.00%
Adjustment for foreign provincial tax rate	(67.00%)
Branch losses	(146.00%)
Equity loss from investments	47.00%
Realized flow-through expenditures	79.00%
Realized flow-through premium	(81.00%)
Deferred mining tax expense net of income tax benefit	10.00%
Withholding taxes	5.00%
Effect of foreign exchange on translation of books and records	(8.00%)
Change in valuation allowance	(176.00%)
Nontaxable/nondeductible items
Foregone interest	(13.00%)
Other adjustments
Adjustments in relation to prior years	(8.00%)
Other	(2.00%)
Argentina
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Adjustment for foreign tax rate	$ (60)
Change in valuation allowance	8
Equity loss from investments	(8,636)
Effect of foreign exchange on translation of books and records	(1,382)
Nontaxable/nondeductible items
Non deductible expense	1,772
Other adjustments
Other	$ 57
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Adjustment for foreign tax rate	(1.00%)
Equity loss from investments	(124.00%)
Effect of foreign exchange on translation of books and records	(20.00%)
Change in valuation allowance	0.00%
Nontaxable/nondeductible items
Non deductible expense	26.00%
Other adjustments
Other	1.00%
Mexico
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Adjustment for foreign tax rate	$ (997)
Change in valuation allowance	1,411
Inflation adjustment on monetary assets	738
Effect of foreign exchange on translation of books and records	372
Nontaxable/nondeductible items
Non deductible expense	695
Other adjustments
Other	$ 108
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Adjustment for foreign tax rate	(14.00%)
Inflation adjustment on monetary assets	11.00%
Effect of foreign exchange on translation of books and records	5.00%
Change in valuation allowance	20.00%
Nontaxable/nondeductible items
Non deductible expense	10.00%
Other adjustments
Other	2.00%