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Fair Value - Fair Value Levels (Details) - USD ($) $ in Thousands | Sep. 30, 2024 | Dec. 31, 2023
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Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | $ 3,265,271 | $ 3,011,322
First lien |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 2,072,485 | 1,683,952
Second lien |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 250,871 | 424,513
Subordinated |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 109,811 | 90,948
Equity and other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 832,104 | 811,909
Level I |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 0 | 0
Level I | First lien |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 0 | 0
Level I | Second lien |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 0 | 0
Level I | Subordinated |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 0 | 0
Level I | Equity and other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 0 | 0
Level II |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 123,386 | 72,473
Level II | First lien |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 53,422 | 46,063
Level II | Second lien |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 59,539 | 18,333
Level II | Subordinated |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 10,425 | 8,077
Level II | Equity and other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 0 | 0
Level III |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 3,141,885 | 2,938,849
Level III | First lien |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 2,019,063 | 1,637,889
Level III | Second lien |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 191,332 | 406,180
Level III | Subordinated |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 99,386 | 82,871
Level III | Equity and other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | $ 832,104 | $ 811,909

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