Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2021	Apr. 30, 2021
Document Information [Line Items]
Entity Central Index Key	0001123494
Entity Registrant Name	HARVARD BIOSCIENCE INC
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2021
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	001-33957
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3306140
Entity Address, Address Line One	84 October Hill Road
Entity Address, City or Town	Holliston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01746
City Area Code	508
Local Phone Number	893-8999
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	HBIO
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		39,956,714