- Definition

Represents the long term gold price per ounce used to find the present value of an amount to be paid or received in the future as an input to measure the fair value.

+ References

No definition available.

+ Details

Name:	mux_FairValueInputsLongTermGoldPricePerOunce
Namespace Prefix:	mux_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents inflation adjustment of the long term gold price per ounce.

+ References

No definition available.

+ Details

Name:	mux_InflationAdjustmentLongTermGoldPricePerOunce
Namespace Prefix:	mux_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage the Company is obligated to sell as part of the streaming agreement.

+ References

No definition available.

+ Details

Name:	mux_PercentageOfGoldProductionObligatedToSell
Namespace Prefix:	mux_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the amount of revenue of the acquiree since the acquisition date and implementation of the streaming agreement.

+ References

No definition available.

+ Details

Name:	mux_RevenueOfAcquireeSinceAquisitionStreamingAgreementImplementation
Namespace Prefix:	mux_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_OtherCommitmentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionAxis=mux_BlackFoxMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=mux_PikeRiverPropertyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

COMMITMENTS AND CONTINGENCIES - Streaming Agreement (Details) $ in Millions		12 Months Ended
	Aug. 25, 2017 $ / oz	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Black Fox
Other commitments
Obligation to sell (as a percent)	8.00%
Long Term Gold Price (in dollars per ounce)	531
Revenue of acquiree since acquisition date and implementation of streaming agreement \| $		$ 0.4	$ 0.0
Black Fox \| Maximum
Other commitments
Inflation adjustment (as a percent)	2.00%
Pike River property
Other commitments
Obligation to sell (as a percent)	6.30%
Long Term Gold Price (in dollars per ounce)	531
Pike River property \| Maximum
Other commitments
Inflation adjustment (as a percent)	2.00%