XML 16 R1.htm IDEA: XBRL DOCUMENT v3.26.1
Document and Entity Information - USD ($)
12 Months Ended
Jan. 31, 2026
Apr. 21, 2026
Jul. 31, 2025
Document and Entity Information      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Jan. 31, 2026    
Document Transition Report false    
Securities Act File Number 1-4488    
Entity Registrant Name MESABI TRUST    
Entity Incorporation, State or Country Code NY    
Entity Tax Identification Number 13-6022277    
Entity Address, Address Line One 1 Columbus Circle, 17th Floor    
Entity Address, Address Line Two Mail Stop: NYC01-1710    
Entity Address, City or Town New York    
Entity Address, State or Province NY    
Entity Address, Postal Zip Code 10019    
City Area Code 904    
Local Phone Number 271-2520    
Title of 12(b) Security Units of Beneficial Interest in Mesabi Trust    
Trading Symbol MSB    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 383,596,142
Entity Common Stock, Shares Outstanding   13,120,010  
Documents Incorporated by Reference [Text Block]

Document

Parts Into Which
Incorporated

Annual Report of the Trustees for the Fiscal Year Ended January 31, 2026 (Annual Report)

Parts I, II, and IV

   
Current Fiscal Year End Date --01-31    
Document Fiscal Year Focus 2026    
Document Fiscal Period Focus FY    
Entity Central Index Key 0000065172    
Amendment Flag false    
Auditor Name Boulay PLLP    
Auditor Firm ID 542    
Auditor Location Minneapolis, Minnesota