SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Risks and Uncertainties (Details)	12 Months Ended
Dec. 31, 2024
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Duration current portion of inventories expected to be processed or recovered	12 months

The duration of the current portion of Inventories is determined based on the expected amounts to be processed and/or recovered.

No definition available.

Name:	mux_DurationOfCurrentPortionOfInventoriesToBeProcessedOrRecovered
Namespace Prefix:	mux_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration