v3.8.0.1
Document and Entity Information - shares
3 Months Ended
Mar. 31, 2018
May 01, 2018
Document And Entity Information    
Entity Registrant Name ACME UNITED CORP  
Entity Central Index Key 0000002098  
Document Type 10-Q  
Document Period End Date Mar. 31, 2018  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Is Entity a Well-known Seasoned Issuer? No  
Is Entity a Voluntary Filer? No  
Is Entity's Reporting Status Current? Yes  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding   3,374,061
Document Fiscal Period Focus Q1  
Document Fiscal Year Focus 2018