Consolidated Statements of Assets and Liabilities (Parenthetical) - USD ($) $ in Thousands |
Mar. 31, 2026 |
Sep. 30, 2025 |
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Investments at cost | $ 2,646,425 | [1],[2],[3],[4] | $ 2,819,393 | [5],[6],[7],[8] | ||||||||||||||||
| Cash at cost | 90,446 | [3],[4] | 81,955 | [7],[8] | ||||||||||||||||
| Cash and cash equivalents at cost | 31,427 | 40,729 | ||||||||||||||||||
| Credit facility payable, cost | $ 328,355 | $ 683,855 | ||||||||||||||||||
| Common stock, shares, issued | 99,217,896 | 99,217,896 | ||||||||||||||||||
| Common stock, shares, outstanding | 99,217,896 | 99,217,896 | ||||||||||||||||||
| Common stock par value | $ 0.001 | $ 0.001 | ||||||||||||||||||
| Common stock, shares authorized | 200,000,000 | 200,000,000 | ||||||||||||||||||
| 2036 Asset-Backed Debt | ||||||||||||||||||||
| Asset-backed debt payable, net | $ 0 | $ 287,000 | ||||||||||||||||||
| Unamortized deferred financing costs | 0 | 2,373 | ||||||||||||||||||
| 2036-R Asset-Backed Debt | ||||||||||||||||||||
| Asset-backed debt payable, net | 287,000 | 266,000 | ||||||||||||||||||
| Unamortized deferred financing costs | 415 | 634 | ||||||||||||||||||
| 2037 Asset-Backed Debt | ||||||||||||||||||||
| Asset-backed debt payable, net | 389,500 | 361,000 | ||||||||||||||||||
| Unamortized deferred financing costs | 2,355 | 2,669 | ||||||||||||||||||
| 2038-R Asset-Backed Debt | ||||||||||||||||||||
| Asset-backed debt payable, net | 287,000 | 0 | ||||||||||||||||||
| Unamortized deferred financing costs | 2,230 | 0 | ||||||||||||||||||
| 2026 Notes Payable | ||||||||||||||||||||
| Notes payable, par | 185,000 | 185,000 | ||||||||||||||||||
| Unamortized deferred financing costs | 2 | 391 | ||||||||||||||||||
| 2029 Notes Payable | ||||||||||||||||||||
| Notes payable, par | 200,000 | 0 | ||||||||||||||||||
| Unamortized deferred financing costs | 4,132 | 0 | ||||||||||||||||||
| Non-controlled, Non-affiliated Investments | ||||||||||||||||||||
| Investments at cost | 2,151,925 | 2,458,018 | ||||||||||||||||||
| Controlled, affiliated investments | ||||||||||||||||||||
| Investments at cost | $ 494,500 | $ 361,375 | ||||||||||||||||||
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