XML 55 R44.htm IDEA: XBRL DOCUMENT
v3.21.2

INVESTMENTS (Details) $ / shares in Units, $ in Thousands |  | 3 Months Ended | 6 Months Ended
--- | --- | --- | ---
Jun. 23, 2021 USD ($) property $ / shares shares | Jun. 30, 2021 project | Jun. 30, 2020 USD ($) | Jun. 30, 2020 USD ($)
Investments rollforward |  |  |  |
Number of projects sold | project |  | 2 |  |
Proceeds from sale of investments |  |  |  | $ 305
Disposal Group |  |  |  |
Investments rollforward |  |  |  |
Number of projects sold | property | 2 |  |  |
Disposal Group | Projects in Nevada |  |  |  |
Investments rollforward |  |  |  |
Cash consideration received | $ 500 |  |  |
Number of common shares | shares | 4,963,455 |  |  |
Warrants received | shares | 2,481,727 |  |  |
Percentage of common shares received | 10.00% |  |  |
Price per common share for each warrant | $ / shares | $ 0.60 |  |  |
Marketable equity securities |  |  |  |
Investments rollforward |  |  |  |
Proceeds from sale of investments |  |  | $ 1,200 | $ 1,300

X
- Definition Shares received as consideration for disposal group. + References No definition available. + Details
Name: | mux_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesReceived
Namespace Prefix: | mux_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Shares received as consideration for disposal group representing percentage of shares issued and outstanding of the acquiree. + References No definition available. + Details
Name: | mux_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesReceivedPercentage
Namespace Prefix: | mux_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Warrants received as consideration for disposal group. + References No definition available. + Details
Name: | mux_DisposalGroupIncludingDiscontinuedOperationConsiderationWarrantsReceived
Namespace Prefix: | mux_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | mux_InvestmentsRollforward
Namespace Prefix: | mux_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of projects sold. + References No definition available. + Details
Name: | mux_NumberOfProjectsSold
Namespace Prefix: | mux_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Exercise price per share or per unit of warrants or rights outstanding. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644 + Details
Name: | us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation. + References No definition available. + Details
Name: | us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The cash inflow associated with the aggregate amount received by the entity through sale or maturity of marketable securities (held-to-maturity or available-for-sale) during the period. + References No definition available. + Details
Name: | us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=mux_ProjectsInNevadaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_AvailableforsaleSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |