EQUITY METHOD INVESTMENTS - Summary of the operating results of Minera Santa Cruz S.A. (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2025	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
EQUITY METHOD INVESTMENTS
Revenue from gold and silver sales	$ 64,623	$ 50,534	$ 46,700	$ 35,696	$ 33,523	$ 52,250	$ 47,476	$ 41,228	$ 197,553	$ 174,477	$ 166,231
Depreciation and depletion									(27,229)	(30,229)	(29,221)
Other expense									10,724	2,651	(29,976)
Income (loss) before income and mining taxes									6,949	(46,739)	67,036
Net income (loss) and comprehensive income (loss) attributable to McEwen shareholders	$ 38,126	$ (462)	$ 3,040	$ (6,270)	$ (8,232)	$ (2,081)	$ (12,995)	$ (20,383)	34,434	(43,691)	55,299
Income tax recovery									$ 27,485	$ 3,048	$ (33,859)
Minera Santa Cruz S.A.
EQUITY METHOD INVESTMENTS
Subsidiary (as a percent)									(100.00%)	(100.00%)	(100.00%)
Revenue from gold and silver sales									$ 459,545	$ 310,411	$ 254,926
Production costs applicable to sales									(248,460)	(215,065)	(177,234)
Depreciation and depletion									(52,969)	(51,188)	(58,935)
Gross profit									158,116	44,158	18,757
Exploration									(13,490)	(11,257)	(9,346)
Other expense									(11,843)	(1,717)	(3,977)
Income (loss) before income and mining taxes									132,783	31,184	5,434
Current and deferred taxes									(44,505)	(6,548)	3,051
Net income (loss) and comprehensive income (loss) attributable to McEwen shareholders									88,278	24,636	8,485
Net income									43,256	12,072	4,157
Amortization of fair value increments									(2,160)	(3,088)	(4,612)
Income tax recovery									29	37	517
Income from investment in MSC, net of amortization									$ 41,125	$ 9,021	$ 62