XML 62 R44.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Note 5 - Transactions With Affiliated Companies (Details Textual) | Dec. 31, 2023
--- | ---
Cadrenal Therapeutics, Inc. [Member] | Investment, Affiliated Issuer, Noncontrolled [Member] |
Equity Ownership, Excluding Consolidated Entity and Equity Method Investee, Percentage | 5.00%

X
- Definition Percentage of ownership of equity interest excluding interest in entity that is consolidated and equity method investee. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name Accounting Standards Codification -Section 50 -Paragraph 1 -SubTopic 10 -Topic 321 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479536/321-10-50-1 + Details
Name: | us-gaap_EquityOwnershipPercentageExcludingConsolidatedEntityAndEquityMethodInvestee
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_InvestmentIssuerNameAxis=hrzn_CadrenalTherapeuticsIncMember
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: |