v3.19.1
Document and Entity Information - shares
3 Months Ended
Mar. 31, 2019
May 03, 2019
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, 2019  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Is Entity's Reporting Status Current? Yes  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding   3,352,130
Document Fiscal Period Focus Q1  
Document Fiscal Year Focus 2019  
Entity Emerging Growth Company? false  
Entity Small Business? true