Document and Entity Information - USD ($)
12 Months Ended
Dec. 31, 2018
Mar. 07, 2019
Jun. 30, 2018
Document And Entity Information [Abstract]      
Document Type 10-K    
Document period end date Dec. 31, 2018    
Amendment flag false    
Document Period Focus FY    
Document Fiscal Year Focus 2018    
Current fiscal year end date --12-31    
Entity central index key 0001123494    
Entity current reporting status Yes    
Entity filer category Accelerated Filer    
Entity registrant name HARVARD BIOSCIENCE INC    
Entity voluntary filers No    
Entity well known seasoned issuer No    
Entity common stock shares outstanding   37,667,783  
Entity public float     $ 153,831,985
Non Affiliate Share Holding     28,753,642
Trading Symbol HBIO    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Small Business true