EQUITY METHOD INVESTMENTS - Summary of the operating results of McEwen Copper (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
Advanced projects									$ (7,961)	$ (7,152)	$ (82,637)
Foreign exchange gain (loss)									(2,041)	1,459	(59,503)
Interest and other income									(7,217)	(4,595)	36,918
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
McEwen Copper Inc.
EQUITY METHOD INVESTMENTS
Subsidiary (as a percent)									(100.00%)	(100.00%)	(100.00%)
Advanced projects									$ (41,925)	$ (114,544)	$ (36,475)
Other expenses									(11,679)	(6,196)	(4,684)
Foreign exchange gain (loss)									(2,701)	2,631	(99,338)
Interest and other income									1,294	19,130	19,356
Income (loss) before income and mining taxes									(55,011)	(98,979)	(121,141)
Net income (loss) and comprehensive income (loss) attributable to McEwen shareholders									(55,011)	(98,979)	(121,141)
Loss from investment in McEwen Copper									$ (25,547)	$ (46,977)	$ (57,821)