XML 66 R56.htm IDEA: XBRL DOCUMENT
v3.8.0.1

COMMITMENTS AND CONTINGENCIES - Streaming Agreement (Details) $ in Thousands |  | 3 Months Ended
--- | --- | ---
Aug. 25, 2017 $ / oz | Mar. 31, 2018 USD ($) | Mar. 31, 2017 USD ($)
Other commitments |  |  |
Revenues |  | $ 41,285 | $ 14,833
Black Fox |  |  |
Other commitments |  |  |
Obligation to sell (as a percent) | 8.00% |  |
Revenues |  | $ 600 | $ 0
Pike River property |  |  |
Other commitments |  |  |
Obligation to sell (as a percent) | 6.30% |  |
Long Term Gold Price (in dollars per ounce) | $ / oz | 539 |  |
Pike River property | Maximum |  |  |
Other commitments |  |  |
Inflation adjustment (as a percent) | 2.00% |  |

X
- 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

X
- 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

X
- 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

X
- 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

X
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
Name: | us-gaap_Revenues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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

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

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