XML 112 R81.htm IDEA: XBRL DOCUMENT
v3.20.1

COMMITMENTS AND CONTINGENCIES - Reclamation Bonds, surety bonds (Details) $ in Thousands, $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2019 CAD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($)
Reclamation Bonds |  |  |
Other assets |  | $ 668 | $ 1,281
Timmins |  |  |
Reclamation Bonds |  |  |
Restrictive time deposits for reclamation bonding |  | $ 100 |
Surety Bonds |  |  |
Reclamation Bonds |  |  |
Percentage of annual fees on surety bonds | 2.00% | 2.00% |
Surety bonds upfront deposit amount |  | $ 0 |
Surety bonding obligation |  | 20,100 |
Surety Bonds | Canada |  |  |
Reclamation Bonds |  |  |
Surety bonding obligation | $ 14.9 | 11,500 |
Reclamation Bonds | Tonkin and Gold Bar Properties |  |  |
Reclamation Bonds |  |  |
Reclamation bonding obligation |  | 20,100 |
Black Fox | Reclamation Bonds |  |  |
Reclamation Bonds |  |  |
Reclamation bonding obligation | $ 14.9 | 11,500 |
Other assets |  |  |
Reclamation Bonds |  |  |
Other assets |  | $ 100 |

X
- Definition It is a type of performance surety bond. This type of surety bond is required by the Bureau of Land Management (BLM) and also by some state government agencies that issue permits for mining type operations. Reclamation bond amounts are not standard. + References No definition available. + Details
Name: | mux_ReclamationBondsBondingObligation
Namespace Prefix: | mux_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the percentage of annual fees on the value of the surety bonds. + References No definition available. + Details
Name: | mux_SuretyBondsAnnualFeesPercentage
Namespace Prefix: | mux_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents a surety bond obligation. It is a promise by a surety or guarantor to pay one party (the obligation) a certain amount if a second party (the principal) fails to meet some obligation, such as fulfilling the terms of a contract. + References No definition available. + Details
Name: | mux_SuretyBondsBondingObligation
Namespace Prefix: | mux_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the amount of upfront deposit on the value of surety bonds. + References No definition available. + Details
Name: | mux_SuretyBondsUpfrontDepositAmount
Namespace Prefix: | mux_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_LossContingenciesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of noncurrent assets classified as other. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_OtherAssetsNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The noncurrent cash, cash equivalents and investments that is restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits classified as long-term; that is not expected to be released from such existing restrictions within one year of the balance sheet date or operating cycle, whichever is longer. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. Includes noncurrent cash equivalents and investments that are similarly restricted as to withdrawal, usage or disposal. + References No definition available. + Details
Name: | us-gaap_RestrictedCashAndInvestmentsNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | mux_MineralPropertyNameAxis=mux_TimminsPropertyInCanadaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_SuretyBondMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_CA
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LossContingenciesByNatureOfContingencyAxis=mux_ReclamationBondMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | mux_MineralPropertyNameAxis=mux_TonkinAndGoldBarPropertiesInAggregateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |