| Document and Entity Information - USD ($) | 12 Months Ended | | |
| Dec. 31, 2021 | Mar. 04, 2022 | Jun. 30, 2021 |
| Document and Entity Information | | | |
| Document Type | 10-K/A | | |
| Document Annual Report | true | | |
| Document Transition Report | false | | |
| Document Period End Date | Dec. 31, 2021 | | |
| Entity File Number | 001-33190 | | |
| Entity Registrant Name | MCEWEN MINING INC. | | |
| Entity Incorporation, State or Country Code | CO | | |
| Entity Tax Identification Number | 84-0796160 | | |
| Entity Address, Address Line One | 150 King Street West | | |
| Entity Address, Address Line Two | Suite 2800 | | |
| Entity Address, City or Town | Toronto | | |
| Entity Address, State or Province | ON | | |
| Entity Address, Country | CA | | |
| Entity Address, Postal Zip Code | M5H 1J9 | | |
| City Area Code | 866 | | |
| Local Phone Number | 441-0690 | | |
| Title of 12(b) Security | Common Stock, no par value | | |
| Trading Symbol | MUX | | |
| Security Exchange Name | NYSE | | |
| Amendment Description | McEwen Mining Inc. (the "Company") is filing this Amendment No. 2 on Form 10-K/A (this "Amendment") to its Annual Report on Form 10-K for the year ended December 31, 2021 filed with the U.S. Securities and Exchange Commission ("SEC") on March 7, 2022 (the "Original Filing"), as previously amended by Amendment No. 1 on Form 10-K/A filed on May 27, 2022 (the "Prior Amendment"), to amend Item 15 of Part IV of the Original Filing, as previously amended, pursuant to Rule 3-09 of Regulation S-X, to include the financial statements and related notes of Minera Santa Cruz S.A ("MSC"), a significant equity investee in which the Company holds a 49% equity ownership interest. In addition, the Company is filing the consent of the independent auditors of MSC and, as required by Rule 12b-15 under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), new certifications by the Company's Chief Executive Officer and Chief Financial Officer.Rule 3-09 of Regulation S-X provides that if a 50%-or-less-owned person accounted for by the equity method meets the first or third condition of the significant subsidiary tests set forth in Rule 1-02(w) of Regulation S-X, substituting 20% for 10%, separate financial statements for such 50%-or-less-owned person shall be filed. These financial statements shall be prepared in accordance with accounting principles generally accepted in the United States of America ("US GAAP") or International Financial Reporting Standards ("IFRS"). MSC met the significant subsidiary test described above for the Company's fiscal years ending December 31, 2021, 2020 and 2019 and accordingly, the Company has included in this Amendment the required Statements of Financial Position as of December 31, 2021 and 2020, and the related Statements of Profit (Loss) and Other Comprehensive Profit (Loss), Statements of Changes in Equity, and Statements of Cash Flows for the years ended December 31, 2021, 2020 and 2019, and the accompanying Notes to the Financial Statements of MSC, prepared in accordance with IFRS. We caution readers that the MSC financial results included in our Annual Report on Form 10-K are presented in accordance with US GAAP and may therefore differ from the MSC results presented as separate financial statements reported under IFRS. No attempt has been made in this Amendment to modify or update the disclosures in the Original Filing except as required to reflect the effect of the revisions discussed herein. Except as otherwise noted herein, this Amendment continues to describe conditions as of the date of the Original Filing and the disclosures contained herein have not been updated to reflect events, results or developments that occurred after the date of the Original Filing, or to modify or update those disclosures affected by subsequent events. Among other things, forward-looking statements made in the Original Filing and Prior Amendment have not been revised to reflect events, results or developments that occurred or facts that became known to us after the date of the Original Filing, and such forward-looking statements should be read in conjunction with our filings with the SEC subsequent to the filing of the Original Filing and Prior Amendment. Accordingly, this Amendment should be read in conjunction with the Original Filing and Prior Amendment and the Company's other filings with the SEC subsequent to March 7, 2022. Furthermore, readers are cautioned to review the reliability of information disclosure, contained in our Annual Report on Form 10-K, pertaining to the disclosure of MSC results. | | |
| Entity Well-known Seasoned Issuer | No | | |
| Entity Voluntary Filers | No | | |
| Entity Current Reporting Status | Yes | | |
| Entity Interactive Data Current | Yes | | |
| Entity Filer Category | Accelerated Filer | | |
| Entity Small Business | false | | |
| Entity Emerging Growth Company | false | | |
| ICFR Auditor Attestation Flag | true | | |
| Entity Shell Company | false | | |
| Entity Public Float | | | $ 633,678,600 |
| Entity Common Stock, Shares Outstanding | | 473,687,391 | |
| Current Fiscal Year End Date | --12-31 | | |
| Document Fiscal Year Focus | 2021 | | |
| Document Fiscal Period Focus | FY | | |
| Entity Central Index Key | 0000314203 | | |
| Amendment Flag | true | | |
| Auditor Location | Toronto, Canada | | |
| Auditor Name | Ernst & Young LLP | | |
| Auditor Firm ID | 1263 | | |
