Quarterly report pursuant to Section 13 or 15(d)

Fair Value of Financial Instruments - Schedule of Quantitative Information of Fair Value Measurements (Details)

v3.23.3
Fair Value of Financial Instruments - Schedule of Quantitative Information of Fair Value Measurements (Details) - Significant Unobservable Inputs (Level 3)
$ in Thousands
Sep. 30, 2023
USD ($)
Dec. 31, 2022
USD ($)
Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 3,091,880 $ 2,795,444
Equity and Warrant Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 102,057 85,966
Market Comparable Companies | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 41,339 30,086
Market Comparable Companies | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 16,640 12,479
Market Comparable Companies | Pharmaceuticals | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 1,086,232 903,427
Market Comparable Companies | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 1,151,128 967,108
Market Comparable Companies | Sustainable and Renewable Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 1,768 3,006
Market Comparable Companies | Lower Middle Market | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 278,012 $ 328,393
Market Comparable Companies | Minimum | Hypothetical Market Yield | Pharmaceuticals | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1142 0.1174
Market Comparable Companies | Minimum | Hypothetical Market Yield | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1156 0.1205
Market Comparable Companies | Minimum | Hypothetical Market Yield | Sustainable and Renewable Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1103 0.1471
Market Comparable Companies | Minimum | Hypothetical Market Yield | Lower Middle Market | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1325 0.1368
Market Comparable Companies | Minimum | Premium/(Discount) | Pharmaceuticals | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input (0.0100) (0.0075)
Market Comparable Companies | Minimum | Premium/(Discount) | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input (0.0075) (0.0100)
Market Comparable Companies | Minimum | Premium/(Discount) | Sustainable and Renewable Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0075 0.0075
Market Comparable Companies | Minimum | Premium/(Discount) | Lower Middle Market | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input (0.0075) (0.0200)
Market Comparable Companies | Minimum | EBITDA Multiple | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 11.1 12.4
Market Comparable Companies | Minimum | EBITDA Multiple | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 11.1 12.4
Market Comparable Companies | Minimum | Revenue Multiple | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.9 0.7
Market Comparable Companies | Minimum | Revenue Multiple | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.8 0.6
Market Comparable Companies | Minimum | Tangible Book Value Multiple | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 1.5 1.6
Market Comparable Companies | Minimum | Discount for Lack of Marketability | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0453 0.0811
Market Comparable Companies | Minimum | Discount for Lack of Marketability | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0561 0.0811
Market Comparable Companies | Maximum | Hypothetical Market Yield | Pharmaceuticals | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.2074 0.1904
Market Comparable Companies | Maximum | Hypothetical Market Yield | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.2025 0.1853
Market Comparable Companies | Maximum | Hypothetical Market Yield | Sustainable and Renewable Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1103 0.1471
Market Comparable Companies | Maximum | Hypothetical Market Yield | Lower Middle Market | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1737 0.1849
Market Comparable Companies | Maximum | Premium/(Discount) | Pharmaceuticals | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0350 0.0175
Market Comparable Companies | Maximum | Premium/(Discount) | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0325 0.0150
Market Comparable Companies | Maximum | Premium/(Discount) | Sustainable and Renewable Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0075 0.0075
Market Comparable Companies | Maximum | Premium/(Discount) | Lower Middle Market | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0175 0.0075
Market Comparable Companies | Maximum | EBITDA Multiple | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 11.1 12.4
Market Comparable Companies | Maximum | EBITDA Multiple | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 11.1 12.4
Market Comparable Companies | Maximum | Revenue Multiple | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 18.9 16.1
Market Comparable Companies | Maximum | Revenue Multiple | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 14.0 8.8
Market Comparable Companies | Maximum | Tangible Book Value Multiple | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 1.5 1.6
Market Comparable Companies | Maximum | Discount for Lack of Marketability | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.2869 0.2890
Market Comparable Companies | Maximum | Discount for Lack of Marketability | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.3050 0.3270
Market Comparable Companies | Weighted Average | Hypothetical Market Yield | Pharmaceuticals | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1409 0.1517
Market Comparable Companies | Weighted Average | Hypothetical Market Yield | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1538 0.1521
Market Comparable Companies | Weighted Average | Hypothetical Market Yield | Sustainable and Renewable Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1103 0.1471
Market Comparable Companies | Weighted Average | Hypothetical Market Yield | Lower Middle Market | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1329 0.1482
Market Comparable Companies | Weighted Average | Premium/(Discount) | Pharmaceuticals | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0002 0.0001
Market Comparable Companies | Weighted Average | Premium/(Discount) | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0038 0.0020
Market Comparable Companies | Weighted Average | Premium/(Discount) | Sustainable and Renewable Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0075 0.0075
Market Comparable Companies | Weighted Average | Premium/(Discount) | Lower Middle Market | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0014 (0.0043)
Market Comparable Companies | Weighted Average | EBITDA Multiple | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 11.1 12.4
Market Comparable Companies | Weighted Average | EBITDA Multiple | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 11.1 12.4
Market Comparable Companies | Weighted Average | Revenue Multiple | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 7.5 7.4
Market Comparable Companies | Weighted Average | Revenue Multiple | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 4.1 3.4
Market Comparable Companies | Weighted Average | Tangible Book Value Multiple | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 1.5 1.6
Market Comparable Companies | Weighted Average | Discount for Lack of Marketability | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.2066 0.1979
Market Comparable Companies | Weighted Average | Discount for Lack of Marketability | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1965 0.1897
Market Adjusted OPM Backsolve | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 7,513 $ 13,795
Market Adjusted OPM Backsolve | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 2,838 $ 6,934
Market Adjusted OPM Backsolve | Minimum | Market Equity Adjustment | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input (0.8681) (0.9782)
Market Adjusted OPM Backsolve | Minimum | Market Equity Adjustment | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input (0.7280) (0.9782)
Market Adjusted OPM Backsolve | Maximum | Market Equity Adjustment | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.2591 0.1634
Market Adjusted OPM Backsolve | Maximum | Market Equity Adjustment | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1871 0.6643
Market Adjusted OPM Backsolve | Weighted Average | Market Equity Adjustment | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input (0.1007) (0.1669)
Market Adjusted OPM Backsolve | Weighted Average | Market Equity Adjustment | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input (0.0358) (0.0886)
Discounted Cash Flow | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 28,668 $ 19,153
Discounted Cash Flow | Minimum | Discount Rate | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1983 0.1772
Discounted Cash Flow | Maximum | Discount Rate | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.3214 0.3013
Discounted Cash Flow | Weighted Average | Discount Rate | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.3056 0.2446
Convertible Note Analysis | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 23,491 $ 20,356
Convertible Note Analysis | Minimum | Probability weighting of alternative outcomes | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0100 0.0100
Convertible Note Analysis | Maximum | Probability weighting of alternative outcomes | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.5000 0.5000
Convertible Note Analysis | Weighted Average | Probability weighting of alternative outcomes | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.3526 0.3579
Liquidation | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 0 $ 0
Liquidation | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 24,555 1,671
Liquidation | Lower Middle Market | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 6,243 $ 8,042
Liquidation | Minimum | Probability weighting of alternative outcomes | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.5000 0.0500
Liquidation | Minimum | Probability weighting of alternative outcomes | Lower Middle Market | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.2000 0.2000
Liquidation | Minimum | Revenue Multiple | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 1.7 2.1
Liquidation | Minimum | Revenue Multiple | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input   6.2
Liquidation | Minimum | Discount for Lack of Marketability | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.8500 0.8500
Liquidation | Minimum | Discount for Lack of Marketability | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input   90.00
Liquidation | Maximum | Probability weighting of alternative outcomes | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.5000 0.8000
Liquidation | Maximum | Probability weighting of alternative outcomes | Lower Middle Market | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.8000 0.8000
Liquidation | Maximum | Revenue Multiple | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 1.7 2.1
Liquidation | Maximum | Revenue Multiple | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input   6.2
Liquidation | Maximum | Discount for Lack of Marketability | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.8500 0.8500
Liquidation | Maximum | Discount for Lack of Marketability | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input   90.00
Liquidation | Weighted Average | Probability weighting of alternative outcomes | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.5000 0.4829
Liquidation | Weighted Average | Probability weighting of alternative outcomes | Lower Middle Market | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.8000 0.8000
Liquidation | Weighted Average | Revenue Multiple | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 1.7 2.1
Liquidation | Weighted Average | Revenue Multiple | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input   6.2
Liquidation | Weighted Average | Discount for Lack of Marketability | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.8500 0.8500
Liquidation | Weighted Average | Discount for Lack of Marketability | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input   90.00
Other | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 4,419 $ 3,513
Other | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 640 6
Debt Investments originated within 6 months | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 394,728 392,168
Imminent Payoffs | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 23,494 77,676
Debt Investments Maturing in Less than One Year | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 102,229 $ 93,597