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