v3.25.4
Document And Entity Information
Feb. 06, 2026
Document Information [Line Items]  
Entity, Registrant Name HORIZON TECHNOLOGY FINANCE CORPORATION
Document, Type 8-K
Document, Period End Date Feb. 06, 2026
Entity, Incorporation, State or Country Code DE
Entity, File Number 814-00802
Entity, Tax Identification Number 27-2114934
Entity, Address, Address Line One 312 Farmington Avenue
Entity, Address, City or Town Farmington
Entity, Address, State or Province CT
Entity, Address, Postal Zip Code 06032
City Area Code 860
Local Phone Number 676-8654
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity, Emerging Growth Company false
Amendment Flag false
Entity, Central Index Key 0001487428
CommonStock Custom [Member]  
Document Information [Line Items]  
Title of 12(b) Security Common Stock
Trading Symbol HRZN
Security Exchange Name NASDAQ
NotesDue2027625 Custom [Member]  
Document Information [Line Items]  
Title of 12(b) Security 6.25% Notes due 2027
Trading Symbol HTFC
Security Exchange Name NYSE