Document and Entity Information Document
 3 Months Ended
Mar. 31, 2015
Apr. 15, 2015
Entity Information    
Entity Registrant Name Tennant Company  
Entity Central Index Key 0000097134  
Document Type 10-Q  
Document Period End Date Mar. 31, 2015  
Current Fiscal Year End Date --12-31  
Entity Well-known Seasoned Issuer Yes  
Entity Voluntary Filers No  
Entity Current Reporting Status Yes  
Entity Filer Category Large Accelerated Filer  
Entity Common Stock, Shares Outstanding   18,402,023
Document Fiscal Year Focus 2015  
Document Fiscal Period Focus Q1  
Amendment Flag false