UNAUDITED SUPPLEMENTARY QUARTERLY INFORMATION (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Unaudited supplementary quarterly information
Revenues									$ 136,541,000	$ 104,789,000	$ 117,019,000
Gross profit (loss)	$ (5,897,000)	$ 344,000	$ 4,059,000	$ (4,986,000)	$ (13,687,000)	$ (701,000)	$ (8,875,000)	$ (3,685,000)	(6,480,000)	(26,948,000)	8,986,000
Net loss					$ (23,542,000)	$ (9,778,000)	$ (19,814,000)	$ (99,191,000)	(56,712,000)	(152,325,000)	(59,747,000)
Net loss attributable to McEwen shareholders	$ (21,028,000)	$ (17,401,000)	$ (5,989,000)	$ (12,466,000)					$ (56,884,000)	$ (152,325,000)	$ (59,747,000)
Net (loss) per share:
Basic (in dollars per share)	$ (0.05)	$ (0.04)	$ (0.01)	$ (0.03)	$ (0.06)	$ (0.02)	$ (0.05)	$ (0.25)	$ (0.12)	$ (0.38)	$ (0.17)
Diluted (in dollars per share)	$ (0.05)	$ (0.04)	$ (0.01)	$ (0.03)	$ (0.06)	$ (0.02)	$ (0.05)	$ (0.25)	$ (0.12)	$ (0.38)	$ (0.17)
Weighted average shares outstanding:
Weighted average common shares outstanding, Basic (shares in thousands)	454,899,000	459,187,000	459,187,000	441,794,000	408,959,000	403,887,000	400,513,000	400,370,000	454,899,000	403,457,000	361,845,000
Weighted average common shares outstanding, Diluted (shares in thousands)	454,899,000	459,187,000	459,187,000	441,794,000	408,959,000.00	403,887,000.00	400,513,000.00	400,370,000.00	454,899,000	403,457,000	361,845,000
Gold and silver sales
Unaudited supplementary quarterly information
Revenues	$ 34,966,000	$ 37,129,000	$ 40,706,000	$ 23,740,000	$ 27,703,000	$ 27,395,000	$ 18,291,000	$ 31,400,000	$ 136,541,000	$ 104,789,000	$ 117,019,000