XML 76 R52.htm IDEA: XBRL DOCUMENT
v3.20.4

OPERATING SEGMENT REPORTING - Summary of Reportable Operating Segments (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2020 | Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Revenue from gold and silver sales |  |  |  |  |  |  |  |  | $ 104,789 | $ 117,019 | $ 128,175
Depreciation and depletion |  |  |  |  |  |  |  |  | (22,910) | (24,753) | (15,079)
Gross (loss) | $ (13,687) | $ (701) | $ (8,875) | $ (3,685) | $ 1,261 | $ 1,619 | $ 4,677 | $ 1,429 | (26,948) | 8,986 | 32,082
Advanced projects |  |  |  |  |  |  |  |  | (11,681) | (9,520) | (15,063)
Impairment of mineral property interests and plant and equipment (Note 9) |  |  |  | (83,800) |  |  |  |  | (83,805) |  |
Loss from investment in Minera Santa Cruz S.A. (Note 10) |  |  |  |  |  |  |  |  | (1,517) | (8,754) | (11,865)
Other operating |  |  |  |  |  |  |  |  | (1,968) |  |
Loss before income and mining taxes |  |  |  |  |  |  |  |  | (153,715) | (63,591) | (47,640)
Capital expenditures |  |  |  |  |  |  |  |  | 13,925 | 30,270 | 97,468
USA |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Depreciation and depletion |  |  |  |  |  |  |  |  | (11,785) | (10,934) |
Gross (loss) |  |  |  |  |  |  |  |  | (21,366) | (701) |
Advanced projects |  |  |  |  |  |  |  |  | (1,071) | (649) | (7,959)
Impairment of mineral property interests and plant and equipment (Note 9) |  |  |  |  |  |  |  |  | (83,805) |  |
Other operating |  |  |  |  |  |  |  |  | (1,390) |  |
Segment loss |  |  |  |  |  |  |  |  | (114,409) | (9,904) | (13,133)
Capital expenditures |  |  |  |  |  |  |  |  | 4,821 | 18,806 | 84,713
Canada |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Depreciation and depletion |  |  |  |  |  |  |  |  | (10,883) | (13,271) | (12,972)
Gross (loss) |  |  |  |  |  |  |  |  | (4,070) | 5,666 | 5,957
Advanced projects |  |  |  |  |  |  |  |  | (6,088) | (1,636) |
Other operating |  |  |  |  |  |  |  |  | (578) |  |
Segment loss |  |  |  |  |  |  |  |  | (17,186) | (21,749) | (16,075)
Capital expenditures |  |  |  |  |  |  |  |  | 9,104 | 11,464 | 12,584
Mexico |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Depreciation and depletion |  |  |  |  |  |  |  |  | (242) | (548) | (2,107)
Gross (loss) |  |  |  |  |  |  |  |  | (1,512) | 4,021 | 26,125
Advanced projects |  |  |  |  |  |  |  |  | (4,522) | (7,235) | (7,104)
Segment loss |  |  |  |  |  |  |  |  | (6,547) | (3,214) | 16,780
Capital expenditures |  |  |  |  |  |  |  |  |  |  | 171
MSC |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Loss from investment in Minera Santa Cruz S.A. (Note 10) |  |  |  |  |  |  |  |  | (1,517) | (8,754) | (11,865)
Segment loss |  |  |  |  |  |  |  |  | (1,517) | (8,754) | (11,865)
Los Azules |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Segment loss |  |  |  |  |  |  |  |  | (2,121) | (3,411) | (7,129)
Total Segment |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Depreciation and depletion |  |  |  |  |  |  |  |  | (22,910) | (24,753) | (15,079)
Gross (loss) |  |  |  |  |  |  |  |  | (26,948) | 8,986 | 32,082
Advanced projects |  |  |  |  |  |  |  |  | (11,681) | (9,520) | (15,063)
Loss from investment in Minera Santa Cruz S.A. (Note 10) |  |  |  |  |  |  |  |  | (1,517) | (8,754) | (11,865)
Segment loss |  |  |  |  |  |  |  |  | (141,780) | (47,032) | (31,422)
General and Administrative and other |  |  |  |  |  |  |  |  | (11,935) | (16,559) | (16,218)
Gold and silver sales |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Revenue from gold and silver sales | $ 27,703 | $ 27,395 | $ 18,291 | $ 31,400 | $ 32,362 | $ 32,691 | $ 36,383 | $ 15,583 | 104,789 | 117,019 | 128,175
Gold and silver sales | USA |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Revenue from gold and silver sales |  |  |  |  |  |  |  |  | 48,884 | 43,847 |
Gold and silver sales | Canada |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Revenue from gold and silver sales |  |  |  |  |  |  |  |  | 41,452 | 50,058 | 62,024
Gold and silver sales | Mexico |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Revenue from gold and silver sales |  |  |  |  |  |  |  |  | 14,453 | 23,114 | 66,151
Gold and silver sales | Total Segment |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Revenue from gold and silver sales |  |  |  |  |  |  |  |  | 104,789 | 117,019 | 128,175
Production costs applicable to sales | USA |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Production costs applicable to sales |  |  |  |  |  |  |  |  | (58,465) | (33,614) |
Production costs applicable to sales | Canada |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Production costs applicable to sales |  |  |  |  |  |  |  |  | (34,639) | (31,121) | (43,095)
Production costs applicable to sales | Mexico |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Production costs applicable to sales |  |  |  |  |  |  |  |  | (15,723) | (18,545) | (37,919)
Production costs applicable to sales | Total Segment |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Production costs applicable to sales |  |  |  |  |  |  |  |  | (108,827) | (83,280) | (81,014)
Exploration | USA |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Production costs applicable to sales |  |  |  |  |  |  |  |  | (6,777) | (8,554) | (5,174)
Exploration | Canada |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Production costs applicable to sales |  |  |  |  |  |  |  |  | (6,450) | (25,779) | (22,032)
Exploration | Mexico |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Production costs applicable to sales |  |  |  |  |  |  |  |  | (513) |  | (2,241)
Exploration | Los Azules |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Production costs applicable to sales |  |  |  |  |  |  |  |  | (2,121) | (3,411) | (7,129)
Exploration | Total Segment |  |  |  |  |  |  |  |  |  |  |
Operating Segment Reporting |  |  |  |  |  |  |  |  |  |  |
Production costs applicable to sales |  |  |  |  |  |  |  |  | $ (15,861) | $ (37,744) | $ (36,576)

X
- Definition The amount of advanced project cost. + References No definition available. + Details
Name: | mux_AdvancedProjectCost
Namespace Prefix: | mux_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line. Includes expenses classified as other. + References No definition available. + Details
Name: | mux_GeneralAndAdministrativeAndOtherExpense
Namespace Prefix: | mux_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets. Includes the cash outflow from the purchase of mining and mining related assets during the period. + References No definition available. + Details
Name: | mux_PaymentsToAcquirePropertyPlantAndEquipmentAndAcquireMiningAssets
Namespace Prefix: | mux_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Segment income or loss for the period. + References No definition available. + Details
Name: | mux_SegmentOperatingIncomeLoss
Namespace Prefix: | mux_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2420-110228 + Details
Name: | us-gaap_AssetImpairmentCharges
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of expense for allocation of cost of tangible and intangible assets over their useful lives, and reduction in quantity of natural resource due to consumption directly used in production of good and rendering of service. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(b)(2)) -URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227 + Details
Name: | us-gaap_CostDepreciationAmortizationAndDepletion
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 924 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 11.L) -URI http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.2(a),(d)) -URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227 + Details
Name: | us-gaap_CostOfGoodsAndServicesSold
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 31 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599 Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1,2) -URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599 + Details
Name: | us-gaap_GrossProfit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 940 -SubTopic 20 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=68072869&loc=d3e41242-110953 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(10)) -URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(8)) -URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 235 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-05(b)(2)) -URI http://asc.fasb.org/extlink&oid=120399901&loc=d3e537907-122884 Reference 9: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 31 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599 Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(15)) -URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 + Details
Name: | us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of income (loss) for proportionate share of equity method investee's income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(12)) -URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(10)) -URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(13)(f)) -URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570 + Details
Name: | us-gaap_IncomeLossFromEquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of other expense that is infrequent in occurrence or unusual in nature. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=114868883&loc=SL114871943-224233 + Details
Name: | us-gaap_OtherNonrecurringExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 40 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9031-108599 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 41 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9038-108599 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 42 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9054-108599 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 235 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-05(b)(2)) -URI http://asc.fasb.org/extlink&oid=120399901&loc=d3e537907-122884 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(1)) -URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227 + Details
Name: | us-gaap_Revenues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_SegmentReportingInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mux_UnitedStatesReportableSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mux_CanadaReportableSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mux_MexicoReportableSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mux_MSCReportableSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mux_LosAzulesReportableSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mux_ReportableSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_MineralMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_ProductMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_MineralExplorationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |