Quarterly report pursuant to Section 13 or 15(d)

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

v3.24.1.u1
Fair Value of Financial Instruments - Schedule of Quantitative Information of Fair Value Measurements (Details) - Significant Unobservable Inputs (Level 3)
$ in Thousands
Mar. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 3,382,970 $ 3,057,299
Equity and Warrant Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 111,629 116,916
Debt Investments and Other Investment Receivables    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 3,385,826 3,066,947
Market Comparable Companies | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 46,154 52,094
Market Comparable Companies | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 16,912 19,014
Market Comparable Companies | Pharmaceuticals | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 973,558 971,775
Market Comparable Companies | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 1,078,024 1,181,823
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 1,566 1,678
Market Comparable Companies | Medical Devices | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 30,480  
Market Comparable Companies | Lower Middle Market | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 399,205 $ 322,162
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 0.1069 0.1091
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 0.1026 0.1130
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 0.1127 0.1075
Market Comparable Companies | Minimum | Hypothetical Market Yield | Medical Devices | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1279  
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 0.1092 0.1254
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 (0.0200) (0.0100)
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 (0.0150) (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 0.0150 0.0075
Market Comparable Companies | Minimum | Premium/(Discount) | Medical Devices | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0050  
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 0.0000 (0.0075)
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   12.3
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   12.3
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 0.3 0.3
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 1.0 0.9
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 1.7 1.8
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 0.0922 0.0711
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 0.0765 0.0621
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 0.2121 0.2143
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 0.1904 0.2074
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 0.1127 0.1075
Market Comparable Companies | Maximum | Hypothetical Market Yield | Medical Devices | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1279  
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 0.1883 0.2015
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 0.0400 0.0350
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 0.0350 0.0500
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 0.0150 0.0075
Market Comparable Companies | Maximum | Premium/(Discount) | Medical Devices | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0050  
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 0.0300 0.0225
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   12.3
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   12.3
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 19.2 20.1
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 12.5 10.2
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 1.7 1.8
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 0.9288 0.9272
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 0.3483 0.3312
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 0.1334 0.1346
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 0.1396 0.1503
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 0.1127 0.1075
Market Comparable Companies | Weighted Average | Hypothetical Market Yield | Medical Devices | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.1279  
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 0.1385 0.1413
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 0.0003 0.0004
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 0.0019 0.0047
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 0.0150 0.0075
Market Comparable Companies | Weighted Average | Premium/(Discount) | Medical Devices | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.0050  
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 0.0092 0.0056
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   12.3
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   12.3
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 6.8 7.2
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 4.3 4.2
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 1.7 1.8
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 0.3610 0.3157
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 0.2342 0.2170
Market Adjusted OPM Backsolve | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 13,271 $ 11,096
Market Adjusted OPM Backsolve | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 2,370 $ 3,074
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 (0.8555) (0.8614)
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 (0.3306) (0.7067)
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 0.5841 0.3269
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 0.6782 0.3486
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 0.2706 0.0747
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 0.1648 0.1317
Discounted Cash Flow | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 29,884 $ 28,713
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 0.2068 0.1988
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 0.3353 0.3197
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 0.3162 0.3051
Convertible Note Analysis | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 24,227 $ 23,244
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 0.6000 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 0.3955 0.3932
Liquidation | Pharmaceuticals | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 5,215 $ 8,455
Liquidation | Technology | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 54,837 0
Liquidation | Other Investment Receivable | Other Investment Receivables    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 2,856 $ 9,648
Liquidation | Minimum | Probability weighting of alternative outcomes | Pharmaceuticals | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.2000 0.1000
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 0.3000 1.0000
Liquidation | Minimum | Probability weighting of alternative outcomes | Other Investment Receivable | Other Investment Receivables    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input   0.1000
Liquidation | Maximum | Probability weighting of alternative outcomes | Pharmaceuticals | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.6000 0.5000
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 1.0000 1.0000
Liquidation | Maximum | Probability weighting of alternative outcomes | Other Investment Receivable | Other Investment Receivables    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input   0.5000
Liquidation | Weighted Average | Probability weighting of alternative outcomes | Pharmaceuticals | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.5120 0.4183
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 0.5201 1.0000
Liquidation | Weighted Average | Probability weighting of alternative outcomes | Other Investment Receivable | Other Investment Receivables    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investment company, investment owned, measurement input 0.3997 0.4183
Other | Equity Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments $ 3,038 $ 2,925
Other | Warrants    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 0 0
Debt Investments originated within 6 months | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 615,126 431,512
Imminent Payoffs | Debt Investments    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Investments 64,479 54,430
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 $ 136,253 $ 62,220