Document and Entity Information - shares
 6 Months Ended
May 31, 2020
Jul. 07, 2020
Document and Entity Information    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date May 31, 2020  
Document Fiscal Year Focus 2020  
Entity Current Reporting Status Yes  
Document Fiscal Period Focus Q2  
Entity Registrant Name Trilogy Metals Inc.  
Entity Central Index Key 0001543418  
Current Fiscal Year End Date --11-30  
Entity Interactive Data Current Yes  
Entity Filer Category Accelerated Filer  
Title of 12(b) Security Common Shares  
Trading Symbol TMQ  
Security Exchange Name NYSE  
Entity Common Stock, Shares Outstanding   140,965,583
Entity Emerging Growth Company false  
Entity Small Business true  
Entity Shell Company false