XML 95 R73.htm IDEA: XBRL DOCUMENT
v3.10.0.1

SHAREHOLDERS' EQUITY (Details) $ / shares in Units, $ in Thousands, $ in Millions |  |  |  |  |  |  |  |  | 12 Months Ended
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 20, 2018 CAD ($) shares | Dec. 20, 2018 USD ($) $ / shares shares | Nov. 08, 2018 USD ($) | Jun. 11, 2018 shares | Dec. 20, 2017 USD ($) | Dec. 19, 2017 USD ($) $ / shares shares | Sep. 22, 2017 USD ($) item $ / shares shares | Apr. 26, 2017 $ / shares shares | Feb. 13, 2017 | Dec. 31, 2018 USD ($) $ / shares shares | Dec. 31, 2017 USD ($) $ / shares shares | Dec. 31, 2016 USD ($) $ / shares shares
Shareholders’ distributions |  |  |  |  |  |  |  |  |  | $ 3,372 | $ 3,059 | $ 2,986
Semi-annual shareholders’ distribution | $ / shares |  |  |  |  |  |  |  |  |  | 0.010 | 0.010 | 0.005
Share repurchase program (in shares) | shares |  |  |  |  |  |  |  |  |  | 0 |  |
Share repurchase program |  |  |  |  |  |  |  |  |  |  |  | $ 582
Common stock issued | shares |  |  |  |  |  |  |  |  |  | 344,560,000 | 337,051,000 |
Shares of common stock issued upon exercise of stock options | shares |  |  |  |  |  |  |  |  |  | 171 | 94 | 1,457
Weighted average exercise price of stock options (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  | $ 1.02 | $ 1.30 | $ 2.48
Exercise of stock options |  |  |  |  |  |  |  |  |  | $ 192 | $ 122 | $ 3,730
Restricted cash |  |  |  |  |  |  |  |  |  | $ 14,685 | 10,000 |
Number of units issued | shares |  |  |  |  |  |  | 20,700,000 |  |  |  |  |
Proceeds from equity sale (note 10) |  |  |  |  |  |  |  |  |  |  | 42,453 |
Number of common stock reserved for issuance | shares |  |  |  |  |  |  |  |  |  | 17,500,000 |  |
Number of warrants issued | item |  |  |  |  |  |  | 10,350,000 |  |  |  |  |
Share price | $ / shares |  |  |  |  |  | $ 2.50 |  |  |  |  |  |
Net proceeds |  |  |  |  |  |  | $ 43,200 |  |  | $ 918 | 39,397 |
Issuance costs |  |  |  |  |  |  | $ 3,400 |  |  |  | 3,353 |
Flow-through share premium received |  |  |  |  |  |  |  |  |  | $ 2,950 | 1,643 |
Warrants issued in connection with the equity issuance (note 10) |  |  |  |  |  |  |  |  |  |  | $ 3,823 |
Equity Incentive Plan |  |  |  |  |  |  |  |  |  |  |  |
Common stock issued | shares |  |  |  |  |  |  |  |  |  | 171,000 | 94,000 |
Weighted average exercise price of stock options (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  | $ 1.02 | $ 1.30 |
Common Stock |  |  |  |  |  |  |  |  |  |  |  |
Shareholders’ distributions |  |  |  |  |  |  |  |  |  | $ 3,372 | $ 3,059 | $ 2,986
Share repurchase program (in shares) | shares |  |  |  |  |  |  |  |  |  |  |  | 558
Share repurchase program |  |  |  |  |  |  |  |  |  |  |  | $ 582
Shares of common stock issued upon exercise of stock options | shares |  |  |  |  |  |  |  |  |  | 182 | 94 | 1,494
Exercise of stock options |  |  |  |  |  |  |  |  |  | $ 192 | $ 122 | $ 3,730
Shares issued in connection with acquisitions (note 10) (in shares) | shares |  |  |  |  |  |  |  |  |  | 178 |  |
Annual return of capital declared (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  | $ 0.01 | $ 0.010 |
Number of units issued | shares |  |  |  |  |  |  |  |  |  | 515 | 20,700 |
Net proceeds |  |  |  |  |  |  |  |  |  | $ 918 | $ 39,397 |
Warrants issued in connection with the equity issuance (note 10) |  |  |  |  |  |  |  |  |  |  | $ 3,823 |
Warrants |  |  |  |  |  |  |  |  |  |  |  |
Number of common share per warrant | shares |  |  |  |  |  |  | 1 |  |  |  |  |
Price per common share for each warrant | $ / shares |  |  |  |  |  |  | $ 2.70 |  |  |  |  |
Flow Through Common Shares |  |  |  |  |  |  |  |  |  |  |  |
Restricted cash |  |  |  |  |  | $ 10,000 |  |  |  | $ 0 |  |
Number of units issued | shares | 6,634,000 | 6,634,000 |  |  |  | 4,000,000 |  |  |  | 6,634 | 4,000 |
Share price | $ / shares |  | $ 2.24 |  |  |  |  |  |  |  |  |  |
Net proceeds | $ 20.0 | $ 14,900 |  |  | $ 14,900 |  |  |  |  | $ 11,145 | $ 7,799 |
Issuance costs |  |  |  |  |  |  |  |  |  | 800 | 500 |
Flow-through share premium received |  |  |  |  |  |  |  |  |  | $ 3,000 | $ 1,600 |
At-the-market (“ATM”) |  |  |  |  |  |  |  |  |  |  |  |
Number of units issued | shares |  |  |  |  |  |  |  |  |  | 514,897 |  |
Proceeds from equity sale (note 10) |  |  |  |  |  |  |  |  |  | $ 900 |  |
Number of common stock reserved for issuance | shares |  |  |  |  |  |  |  |  |  | 89,100,000 |  |
Aggregate offering price |  |  | $ 90,000 |  |  |  |  |  |  |  |  |
Lexam VG Gold |  |  |  |  |  |  |  |  |  |  |  |
Shares issued in connection with acquisitions (note 10) (in shares) | shares |  |  |  |  |  |  |  | 12,687,035 |  |  |  |
Ratio of Company's share for acquired company's share |  |  |  |  |  |  |  |  | 0.056% |  |  |
Number of units issued | shares |  |  |  |  |  |  |  | 12,687,035 |  |  |  |
Share price | $ / shares |  |  |  |  |  |  |  | $ 3.00 |  |  |  |
Lexam VG Gold | Common Stock |  |  |  |  |  |  |  |  |  |  |  |
Shares issued in connection with acquisitions (note 10) (in shares) | shares |  |  |  |  |  |  |  |  |  |  | 12,687 |
Black Fox |  |  |  |  |  |  |  |  |  |  |  |
Shares issued in connection with acquisitions (note 10) (in shares) | shares |  |  |  | 178,321 |  |  |  |  |  |  |  |

X
- Definition The annual return of capital distributions declared by the Board of Directors. + References No definition available. + Details
Name: | mux_AnnualReturnOfCapitalDistribution
Namespace Prefix: | mux_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Shares of common stock of the Company at a ratio of the Company’s common stock for each acquired company's share. + References No definition available. + Details
Name: | mux_CommonStockExchangeRatioForAcquisition
Namespace Prefix: | mux_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum aggregate offering price on sale of common shares under the equity distribution agreement. + References No definition available. + Details
Name: | mux_EquityDistributionAgreementSaleOfSharesMaximumAggregateOfferingPrice
Namespace Prefix: | mux_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Current portion of the liability for flow-through share premium. Flow-through shares (FTSs) may be issued by certain corporations in the mining, oil and gas, and renewable energy and energy conservation sectors may issue FTSs to help finance their exploration and project development activities. Flow-through shares must be newly issued shares that have the attributes generally attached to common shares. + References No definition available. + Details
Name: | mux_FlowThroughSharePremiumCurrent
Namespace Prefix: | mux_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Represents the number of warrants issued per unit. + References No definition available. + Details
Name: | mux_NumberOfWarrantPerUnit
Namespace Prefix: | mux_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The return of capital distribution declared per common share. + References No definition available. + Details
Name: | mux_ReturnOfCapitalDistributionDeclaredPerCommonShare
Namespace Prefix: | mux_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | duration

X
- Definition Return of capital paid to shareholders of the Company. + References No definition available. + Details
Name: | mux_StockholdersEquityPaymentsOfCapitalDistribution
Namespace Prefix: | mux_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Value of warrants which are equity-linked financial instruments and should be accounted for permanently in the Shareholder’s Equity section in the Consolidated Balance Sheet. + References No definition available. + Details
Name: | mux_WarrantsEquityLinkedFinancialInstrument
Namespace Prefix: | mux_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Exercise price per share or per unit of warrants or rights outstanding. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(4)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of securities into which each warrant or right may be converted. For example, but not limited to, each warrant may be converted into two shares. + References No definition available. + Details
Name: | us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate number of common shares reserved for future issuance. + 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 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. + 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockSharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cash outflow for cost incurred directly with the issuance of an equity security. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585 + Details
Name: | us-gaap_PaymentsOfStockIssuanceCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash inflow from the additional capital contribution to the entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=98513485&loc=SL98516268-108586 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(1)(a)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(2)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_RestrictedCash
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Weighted average price at which option holders acquired shares when converting their stock options into shares. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Price of a single share of a number of saleable stocks of a company. + References No definition available. + Details
Name: | us-gaap_SharePrice
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of shares of stock issued during the period pursuant to acquisitions. + 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: 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(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesAcquisitions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of new stock issued during the period. + 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 4: 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(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of share options (or share units) exercised during the current period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(2) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: 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(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 3: 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: 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(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodValueNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Value of stock issued as a result of the exercise of stock options. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29-31) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Number of shares that have been repurchased during the period and are being held in treasury. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_TreasuryStockSharesAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_TreasuryStockValueAcquiredCostMethod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_PlanNameAxis=mux_EquityIncentivePlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_WarrantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=mux_IssuanceOfFlowThroughCommonSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=mux_AtMarketMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mux_LexamVgGoldMember
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: |