OPERATING SEGMENT REPORTING - Geographic information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Revenues from External Customers and Long-Lived Assets
Non-current Assets	$ 586,695		$ 604,578
Revenue	41,228	$ 34,752
Investment in MSC or McEwen Copper	308,135		326,147
Minera Santa Cruz S.A.
Revenues from External Customers and Long-Lived Assets
Revenue	65,927	45,740
USA
Revenues from External Customers and Long-Lived Assets
Non-current Assets	73,028		71,234
Revenue	25,278	11,587
Canada
Revenues from External Customers and Long-Lived Assets
Non-current Assets	61,908		83,674
Revenue	14,750	$ 23,165
Mexico
Revenues from External Customers and Long-Lived Assets
Non-current Assets	31,116		30,304
Revenue	1,200
Argentina
Revenues from External Customers and Long-Lived Assets
Non-current Assets	420,643		419,366
Argentina | Minera Santa Cruz S.A.
Revenues from External Customers and Long-Lived Assets
Investment in MSC or McEwen Copper	94,500		93,200
Argentina | McEwen Copper Inc.
Revenues from External Customers and Long-Lived Assets
Investment in MSC or McEwen Copper	$ 308,100		$ 326,100