XML 44 R33.htm IDEA: XBRL DOCUMENT
v3.24.2

Consolidated Schedule of Investments (Unaudited) - Investments (Details) (Parentheticals) | Jun. 30, 2024 | Dec. 31, 2023
--- | --- | ---
NAV % | 196.70% | 218.90%
Investment, Affiliated Issuer, Controlled [Member] |  |
NAV % |  | 4.40%
Investment, Affiliated Issuer, Controlled [Member] | Debt Investments [Member] |  |
NAV % | 3.50% |
Investment, Affiliated Issuer, Noncontrolled [Member] |  |
NAV % |  | 0.30%
Investment, Unaffiliated Issuer [Member] |  |
NAV % | 188.40% | 214.20%
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] |  |
NAV % | 66.60% |
Unrestricted Short Term Investments [Member] |  |
NAV % | 9.80% | 1.00%
Restricted Short Term Investments [Member] |  |
NAV % | 1.00% | 0.80%
Debt Securities [Member] | Investment, Affiliated Issuer, Controlled [Member] | Consumer-related Technologies [Member] |  |
NAV % | 1.70% | 1.60%
Debt Securities [Member] | Investment, Affiliated Issuer, Noncontrolled [Member] |  |
NAV % | 4.80% |
Debt Securities [Member] | Investment, Affiliated Issuer, Noncontrolled [Member] | Life Science [Member] |  |
NAV % | 4.80% | 0.30%
Debt Securities [Member] | Investment, Unaffiliated Issuer [Member] |  |
NAV % | 178.80% | 205.00%
Debt Securities [Member] | Investment, Unaffiliated Issuer [Member] | Life Science [Member] |  |
NAV % |  | 75.60%
Debt Securities [Member] | Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] |  |
NAV % |  | 83.30%
Debt Securities [Member] | Investment, Unaffiliated Issuer [Member] | Healthcare Information and Services Segment [Member] |  |
NAV % | 19.70% | 21.50%
Debt Securities [Member] | Investment, Unaffiliated Issuer [Member] | Sustainability Segment [Member] |  |
NAV % | 21.00% | 24.60%
Equity Securities [Member] | Investment, Affiliated Issuer, Controlled [Member] | Technology Sector [Member] |  |
NAV % | 0.00% | 0.90%
Equity Securities [Member] | Investment, Affiliated Issuer, Noncontrolled [Member] | Life Science [Member] |  |
NAV % | 0.00% | 0.00%
Equity Securities [Member] | Investment, Unaffiliated Issuer [Member] |  |
NAV % | 2.10% | 1.50%
Warrant [Member] | Investment, Affiliated Issuer, Noncontrolled [Member] | Life Science [Member] |  |
NAV % | 0.00% | 0.00%
Warrant [Member] | Investment, Unaffiliated Issuer [Member] |  |
NAV % | 6.50% | 7.60%
Warrant [Member] | Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] |  |
NAV % | 4.00% | 4.50%
Warrant [Member] | Investment, Unaffiliated Issuer [Member] | Healthcare Information and Services Segment [Member] |  |
NAV % | 0.40% | 0.60%
Warrant [Member] | Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] |  |
NAV % | 1.90% | 2.30%
Warrant [Member] | Investment, Unaffiliated Issuer [Member] | Sustainability Segment [Member] |  |
NAV % | 0.20% | 0.20%
Other Investments [Member] | Investment, Affiliated Issuer, Controlled [Member] | Life Science [Member] |  |
NAV % | 1.80% | 1.90%
Other Investments [Member] | Investment, Unaffiliated Issuer [Member] | Life Science [Member] |  |
NAV % | 1.00% | 0.10%
Debt Investments [Member] | Investment, Unaffiliated Issuer [Member] | Life Science [Member] |  |
NAV % | 71.50% |

X
- Definition The NAV percent of investment owned. + References No definition available. + Details
Name: | hrzn_InvestmentOwnedNavPercent
Namespace Prefix: | hrzn_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_InvestmentIssuerAffiliationAxis=us-gaap_InvestmentAffiliatedIssuerControlledMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=hrzn_DebtInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentIssuerAffiliationAxis=us-gaap_InvestmentAffiliatedIssuerNoncontrolledMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentIssuerAffiliationAxis=us-gaap_InvestmentUnaffiliatedIssuerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EquitySecuritiesByIndustryAxis=us-gaap_TechnologySectorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=hrzn_UnrestrictedShortTermInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=hrzn_RestrictedShortTermInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_DebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EquitySecuritiesByIndustryAxis=hrzn_ConsumerrelatedTechnologiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EquitySecuritiesByIndustryAxis=hrzn_LifeScienceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EquitySecuritiesByIndustryAxis=hrzn_HealthcareInformationAndServicesSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EquitySecuritiesByIndustryAxis=hrzn_SustainabilitySegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_WarrantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EquitySecuritiesByIndustryAxis=hrzn_LifeScienceSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_OtherInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=hrzn_DebtInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |