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DISTRIBUTIONS TO COMMON STOCKHOLDERS - Schedule of Dividends Declared (Details) - $ / shares | 12 Months Ended
--- | ---
Sep. 30, 2025 | Sep. 30, 2024
Class of Stock [Line Items] |  |
Common stock dividends paid (in USD per share) | $ 2.48 | $ 1.98
O 2025 M1 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) | 0.165 |
O 2025 M2 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) | 0.165 |
O 2025 M3 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) | 0.165 |
Common stock, dividends, paid, supplemental (in USD per share) | 0.400 |
O 2025 M4 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) | 0.165 |
O 2025 M5 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) | 0.165 |
O 2025 M6 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) | 0.165 |
O 2025 M7 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) | 0.165 |
O 2025 M8 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) | 0.165 |
O 2025 M9 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) | 0.165 |
O 2025 M10 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) | 0.165 |
O 2025 M11 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) | 0.165 |
O 2025 M12 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) | 0.165 |
Common stock, dividends, paid, supplemental (in USD per share) | $ 0.100 |
O 2024 M1 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) |  | 0.165
O 2024 M2 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) |  | 0.165
O 2024 M3 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) |  | 0.165
O 2024 M4 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) |  | 0.165
O 2024 M5 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) |  | 0.165
O 2024 M6 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) |  | 0.165
O 2024 M7 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) |  | 0.165
O 2024 M8 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) |  | 0.165
O 2024 M9 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) |  | 0.165
O 2024 M10 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) |  | 0.165
O 2024 M11 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) |  | 0.165
O 2024 M12 Dividends |  |
Class of Stock [Line Items] |  |
Common stock, dividends, paid, ordinary (in USD per share) |  | $ 0.165

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