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Fair Value - Fair Value Levels (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022
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Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | $ 3,011,322 | $ 3,221,247
First lien |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 1,683,952 | 1,753,967
Second lien |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 424,513 | 561,207
Subordinated |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 90,948 | 76,659
Equity and other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 811,909 | 829,414
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 | 72,473 | 84,956
Level II | First lien |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 46,063 | 0
Level II | Second lien |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 18,333 | 81,139
Level II | Subordinated |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 8,077 | 3,817
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 | 2,938,849 | 3,136,291
Level III | First lien |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 1,637,889 | 1,753,967
Level III | Second lien |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 406,180 | 480,068
Level III | Subordinated |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | 82,871 | 72,842
Level III | Equity and other |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Total investments | $ 811,909 | $ 829,414

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