Document And Entity Information
9 Months Ended
May 31, 2014
Jul. 11, 2014
Document and Entity Information [Abstract]    
Entity Registrant Name Northern Technologies International Corporation  
Document Type 10-Q  
Current Fiscal Year End Date --08-31  
Entity Common Stock, Shares Outstanding   4,480,902
Amendment Flag false  
Entity Central Index Key 0000875582  
Entity Current Reporting Status Yes  
Entity Voluntary Filers No  
Entity Filer Category Smaller Reporting Company  
Entity Well-known Seasoned Issuer No  
Document Period End Date May 31, 2014  
Document Fiscal Year Focus 2014  
Document Fiscal Period Focus Q3