XML 58 R42.htm IDEA: XBRL DOCUMENT v3.26.1

Note 4 - Investments (Details Textual) - CRFH Joint Venture [Member] - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2026	Mar. 18, 2026
Amount Committed to Invest		$ 87,500
Payments to Acquire Investments	$ 0
CR Financial Holdings [Member]
Amount Committed to Invest		$ 12,500

X

- Definition

Represents the amount committed to invest by the entity.

+ References

No definition available.

+ Details

Name:	hrzn_AmountCommittedToInvest
Namespace Prefix:	hrzn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The cash outflow associated with the purchase of all investments (debt, security, other) during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-13

+ Details

Name:	us-gaap_PaymentsToAcquireInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=hrzn_CrfhJointVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=hrzn_CrFinancialHoldingsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: