Document And Entity Information
 12 Months Ended
Dec. 31, 2021
shares
Document Information [Line Items]  
Entity Registrant Name MAG SILVER CORP
Document, Type 40-F
Current Fiscal Year End Date --12-31
Document Fiscal Period Focus FY
Document Fiscal Year Focus 2021
Document, Annual Report true
Document, Period End Date Dec. 31, 2021
Entity, File Number 001-33574
Entity, Incorporation, State or Country Code A1
Entity, Address, Address Line One 800 West Pender Street, Suite 770
Entity, Address, City or Town Vancouver
Entity, Address, State or Province BC
Entity, Address, Postal Zip Code V6C 2V6
City Area Code 604
Local Phone Number 630-1399
Title of 12(b) Security Common Shares, without par value
Trading Symbol MAG
Security Exchange Name NYSE
Entity, Common Stock Shares, Outstanding 97,809,441
Entity, Current Reporting Status Yes
Entity, Interactive Data, Current Yes
Entity, Emerging Growth Company false
ICFR Auditor Attestation Flag true
Auditor Name Deloitte LLP
Auditor Location Vancouver, British Columbia, Canada
Auditor Firm ID 1208
Amendment Flag false
Entity Central Index Key 0001230992
Document Registration Statement false
Annual Information Form true
Audited Annual Financial Statements true
Business Contact [Member]  
Document Information [Line Items]  
Entity, Address, Address Line One 850 Library Avenue, Suite 204
Entity, Address, City or Town Newark
Entity, Address, State or Province DE
Entity, Address, Postal Zip Code 19711
City Area Code 302
Local Phone Number 738-6680
Contact Personnel Name Puglisi & Associates