Basis of Presentation and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
Summary of Significant Accounting Policies [Abstract]
Basis of Presentation Policies [Text Block]	Basis of Presentation The unaudited consolidated financial statements of Harvard Bioscience, Inc. and its wholly-owned subsidiaries (collectively, Harvard Bioscience or the Company) as of March 31, 2019 and for the three months ended March 31, 2019 and 2018 have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles (U.S. GAAP) have been condensed or omitted pursuant to such rules and regulations. The December 31, 2018 consolidated balance sheet was derived from audited financial statements, but does not include all disclosures required by U.S. GAAP. However, the Company believes that the disclosures are adequate to make the information presented not misleading. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018, which was filed with the SEC on March 18, 2019. In the opinion of management, all adjustments, which include normal recurring adjustments necessary to present a fair statement of financial position as of March 31, 2019, results of operations and comprehensive income (loss) for the three months ended March 31, 2019 and 2018 and cash flows for the three months ended March 31, 2019 and 2018, as applicable, have been made. The results of operations for the three months ended March 31, 2019 are not necessarily indicative of the operating results for the full fiscal year or any future periods.
Reclassifications [Policy Text Block]	Reclassifications As disclosed in Note 5, on January 22, 2018, the Company sold substantially all the assets of its operating subsidiary, Denville Scientific, Inc. (Denville). The sale of Denville represented a strategic shift that had a major effect on the Company’s operations and financial results. As such and pursuant to Accounting Standards Codification (ASC) 205-20 – Presentation of Financial Statements - Discontinued Operations, the operating results of Denville for the three months ended March 31, 2018 have been presented in discontinued operations in the consolidated statements of operations. These reclassifications and adjustments had no effect on total amounts within the consolidated balance sheet, consolidated statements of operations and comprehensive income (loss), consolidated statements of cash flows for any of the periods presented.
Leases [Policy Text Block]	Leases The Company accounts for its leases in accordance with ASC 842 Leases. The Company leases office space, manufacturing facilities, automobiles and equipment. The Company concludes on whether an arrangement is a lease at inception. This determination as to whether an arrangement contains a lease is based on an assessment as to whether a contract conveys the right to the Company to control the use of identified property, plant or equipment for period of time in exchange for consideration. Leases with an initial term of 12 months or less are not recorded on the balance sheet. The Company recognizes these lease expenses on a straight line basis over the lease term. As of March 31, 2019, the Company has assessed its contracts and concluded that its leases consist of operating leases. Operating leases are included in operating lease right-of-use (ROU) assets, current portion of operating lease liabilities, and operating lease liabilities in the Company’s consolidated balance sheets. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company determines an incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The incremental borrowing rate represents a significant judgment that is based on an analysis of the Company’s credit rating, country risk, treasury and corporate bond yields, as well as comparison to the Company’s borrowing rate on its most recent loan. The Company uses the implicit rate when readily determinable. The operating lease ROU asset also includes any lease payments made and excludes lease incentives. Lease expense for lease payments is recognized on a straight-line basis over the lease term. The Company has lease agreements with lease and non-lease components, which are generally accounted for separately. Additionally, for its leases, the Company applies a portfolio approach to effectively account for the operating lease ROU assets and liabilities.