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Fair Value of Financial Instruments - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Total net change in unrealized appreciation (depreciation) | $ (46,240) | $ (2,089) | $ (6,277) | $ (87,147) |
2033 Notes |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Current price per par value (in dollars per share) | $ 24.05 |  | $ 24.05 |  | $ 24.59
2031 Asset-Backed Notes |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Current price per par value (in dollars per share) | 0.930 |  | $ 0.930 |  | $ 0.951
Common Stock Investment | Unobservable Inputs (Level 3) | Appreciation |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Total net change in unrealized appreciation (depreciation) |  |  | $ 10,700 | 9,500 |
Preferred Stock Investments | Unobservable Inputs (Level 3) | Depreciation |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Total net change in unrealized appreciation (depreciation) |  |  | (2,000) | (23,200) |
Debt | Unobservable Inputs (Level 3) | Depreciation |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Total net change in unrealized appreciation (depreciation) |  |  |  | (12,200) |
Debt | Unobservable Inputs (Level 3) | Appreciation |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Total net change in unrealized appreciation (depreciation) |  |  | (16,900) |  |
Warrants | Unobservable Inputs (Level 3) | Depreciation |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Total net change in unrealized appreciation (depreciation) |  |  | $ (900) | $ (13,400) |
Underwriting | 2033 Notes |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Current price per par value (in dollars per share) | $ 25.00 |  | $ 25.00 |  |

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- 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/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-3 + Details
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