XML 14 R1.htm IDEA: XBRL DOCUMENT v3.20.1
Document and Entity Information - shares
3 Months Ended
Apr. 30, 2020
Jun. 05, 2020
Document and Entity Information    
Document Type 10-Q  
Document Period End Date Apr. 30, 2020  
Entity Registrant Name MESABI TRUST  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   13,120,010
Current Fiscal Year End Date --01-31  
Document Fiscal Year Focus 2021  
Document Fiscal Period Focus Q1  
Entity Central Index Key 0000065172  
Amendment Flag false