v3.23.3

Portfolio Investments - Composition of Investments (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Sep. 30, 2022
--- | --- | ---
Schedule of Investments [Line Items] |  |
Investment owned, at cost | $ 3,044,119 | $ 2,617,754
Investments at fair value | 2,892,420 | 2,494,111
Debt investments, fair value | $ 2,719,775 | $ 2,369,862
% of Debt Portfolio | 100.00% | 100.00%
Investments in debt securities |  |
Schedule of Investments [Line Items] |  |
Investment owned, at cost | $ 2,654,484 | $ 2,294,392
Investments at fair value | 2,557,102 | 2,223,329
Investments in equity securities |  |
Schedule of Investments [Line Items] |  |
Investment owned, at cost | 171,858 | 127,596
Investments at fair value | 143,767 | 103,534
Debt investments in the JVs |  |
Schedule of Investments [Line Items] |  |
Investment owned, at cost | 162,986 | 146,444
Investments at fair value | 162,673 | 146,533
Equity investments in the JVs |  |
Schedule of Investments [Line Items] |  |
Investment owned, at cost | 54,791 | 49,322
Investments at fair value | 28,878 | 20,715
Floating rate debt securities, including the debt investments in the JVs |  |
Schedule of Investments [Line Items] |  |
Debt investments, fair value | $ 2,345,205 | $ 2,049,644
% of Debt Portfolio | 86.23% | 86.49%
Fixed rate debt securities |  |
Schedule of Investments [Line Items] |  |
Debt investments, fair value | $ 374,570 | $ 320,218
% of Debt Portfolio | 13.77% | 13.51%

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