XML 56 R44.htm IDEA: XBRL DOCUMENT
v3.25.3

Fair Value of Financial Instruments - Schedule of Equity Investments (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |  |
Total net change in unrealized appreciation (depreciation) | $ 32,989 | $ (13,894) | $ 55,214 | $ (44,982)
Significant Unobservable Inputs (Level 3) | Debt investments |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |  |
Total net change in unrealized appreciation (depreciation) |  |  | 17,300 | (32,300)
Significant Unobservable Inputs (Level 3) | Preferred stock |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |  |
Total net change in unrealized appreciation (depreciation) |  |  | (6,300) | (9,200)
Significant Unobservable Inputs (Level 3) | Common stock |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |  |
Total net change in unrealized appreciation (depreciation) |  |  | (2,500) | (300)
Significant Unobservable Inputs (Level 3) | Warrant investments |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |  |
Total net change in unrealized appreciation (depreciation) |  |  | $ 1,600 | $ (800)

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 805 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479328/805-10-50-8 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 805 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 43 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479303/805-10-55-43 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 103 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-103 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of unrealized gain (loss) on investment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 + Details
Name: | us-gaap_UnrealizedGainLossOnInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

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