Significant Accounting Policies and Recent Accounting Updates (Details) |
3 Months Ended | 9 Months Ended | |||
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Jun. 30, 2026
USD ($)
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Jun. 30, 2025
USD ($)
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Jun. 30, 2026
USD ($)
segment
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Jun. 30, 2025
USD ($)
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Sep. 30, 2025
USD ($)
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| Accounting Policies [Abstract] | |||||
| Amortization of deferred loan origination fees, net | $ 1,241,000 | $ 12,956,000 | $ 14,779,000 | $ 29,309,000 | |
| Interest income, operating, accretion of discounts | 4,524,000 | 3,886,000 | 14,302,000 | 9,747,000 | |
| Payment-in-kind interest income | 12,912,000 | 5,748,000 | 36,499,000 | 15,222,000 | |
| Payment-in-kind interest capitalized | 12,777,000 | 5,295,000 | 36,363,000 | 14,928,000 | |
| Investment company, premium prepayment fees | 210,000 | 284,000 | 828,000 | 284,000 | |
| Interest and fee income | 189,518,000 | 113,969,000 | 594,325,000 | 297,335,000 | |
| Non-cash preferred dividends | 668,000 | 435,000 | 1,926,000 | 649,000 | |
| Dividend income, operating, paid in kind | 668,000 | 435,000 | 1,926,000 | 649,000 | |
| Proceeds from dividends received | 255,000 | 0 | 255,000 | 0 | |
| Dividend income received in cash | 1,000 | 1,000 | 33,000 | 1,000 | |
| Return of capital | 1,000 | 1,000 | 35,000 | 1,000 | |
| Non-accrual status loans | 5,755,000 | 5,755,000 | $ 2,381,000 | ||
| Excise tax expense | 0 | 0 | 0 | 0 | |
| Income tax expense | 0 | 0 | 0 | 0 | |
| Deferred debt issuance cost | 46,904,000 | 46,904,000 | $ 38,246,000 | ||
| Amortization of deferred debt issuance costs | 3,853,000 | 2,131,000 | 10,054,000 | 5,305,000 | |
| Amortization of deferred offering costs | $ 1,062,000 | $ 507,000 | $ 2,513,000 | $ 1,597,000 | |
| Number of operating segments | segment | 1 | ||||
| Number of reportable segments | segment | 1 | ||||
| X | ||||||||||
- Definition Amortization Of Deferred Offering Costs No definition available.
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- Definition Dividend Income, Operating, Non-Cash Capitalized No definition available.
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- Definition Interest And Fee Income, Operating, Paid In Cash No definition available.
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- Definition Interest Income, Operating, Accretion Of Discounts No definition available.
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- Definition Interest Income, Operating, Paid-In-Kind, Capitalized No definition available.
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- Definition Investment Company, Premium Prepayment Fees No definition available.
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- Definition Investment Income, Operating, Tax Expense (Benefit), Excise Tax No definition available.
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- Definition Investment Income, Operating, Tax Expense (Benefit), Income Tax No definition available.
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- References No definition available.
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- Definition The net increase(decrease) in interest income during the period representing the allocation of deferred loan origination fees less deferred loan origination costs using the effective interest method over the term of the debt arrangement to which they pertain taking into account the effect of prepayments. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount of amortization expense attributable to debt issuance costs. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount of deferred tax liability attributable to taxable temporary differences from debt issuance costs. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount of dividend income from investment paid in cash, classified as operating. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of dividend income from investment paid in kind, classified as operating. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition This item represents the aggregate fair value of loans held as assets that are in nonaccrual status for which the fair value option has been elected, if the entity's policy is to recognize interest income separately from other changes in fair value. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of interest income from investment paid in kind, classified as operating. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of distribution in excess of tax-basis earnings and profit of investment company. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Dividends received on equity and other investments during the current period. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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