Portfolio Investments - Summarized Balance Sheet Information (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2025 |
Jun. 30, 2024 |
Sep. 30, 2024 |
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| Investment Company, Nonconsolidated Subsidiary [Line Items] | ||||
| Investments at fair value | $ 2,809,377 | $ 2,809,377 | $ 3,021,279 | |
| Cash and cash equivalents | 79,799 | 79,799 | 63,966 | |
| Restricted cash | 0 | 0 | 14,577 | |
| Other assets | 6,585 | 6,585 | 775 | |
| Total assets | 2,964,212 | 2,964,212 | 3,198,341 | |
| Senior credit facility payable | 510,000 | 510,000 | 710,000 | |
| Secured borrowings | 0 | 0 | 5,766 | |
| Other liabilities | 2,381 | 2,381 | 4,088 | |
| Total liabilities | 1,487,743 | 1,487,743 | 1,710,530 | |
| Total liabilities and net assets | 2,964,212 | 2,964,212 | 3,198,341 | |
| Investment owned, at cost | 3,012,589 | 3,012,589 | 3,144,919 | |
| SLF JV I | ||||
| Investment Company, Nonconsolidated Subsidiary [Line Items] | ||||
| Investments at fair value | 332,977 | 332,977 | 329,496 | |
| Cash and cash equivalents | 20,122 | 20,122 | 36,082 | |
| Restricted cash | 2,516 | 2,516 | 6,994 | |
| Other assets | 2,389 | 2,389 | 3,260 | |
| Total assets | 358,004 | 358,004 | 375,832 | |
| Senior credit facility payable | 197,000 | 197,000 | 200,000 | |
| Secured borrowings | 0 | 0 | 11,311 | |
| Notes payable at fair value | 128,750 | 128,750 | 128,750 | |
| Other liabilities | 15,243 | 15,243 | 10,007 | |
| Total liabilities | 340,993 | 340,993 | 350,068 | |
| Members' equity | 17,011 | 17,011 | 25,764 | |
| Total liabilities and net assets | 358,004 | 358,004 | 375,832 | |
| Investment owned, at cost | 348,377 | 348,377 | 337,882 | |
| Net proceeds | 128,750 | $ 128,750 | ||
| Glick JV LLC | ||||
| Investment Company, Nonconsolidated Subsidiary [Line Items] | ||||
| Investments at fair value | 109,333 | 109,333 | 124,887 | |
| Cash and cash equivalents | 17,294 | 17,294 | 10,907 | |
| Restricted cash | 941 | 941 | 1,032 | |
| Other assets | 970 | 970 | 8,177 | |
| Total assets | 128,538 | 128,538 | 145,003 | |
| Senior credit facility payable | 69,000 | 69,000 | 79,000 | |
| Notes payable at fair value | 53,788 | 53,788 | 55,886 | |
| Other liabilities | 5,750 | 5,750 | 4,351 | |
| Total liabilities | 128,538 | 128,538 | 145,003 | |
| Members' equity | 0 | 0 | 0 | |
| Total liabilities and net assets | 128,538 | 128,538 | 145,003 | |
| Investment owned, at cost | 114,441 | 114,441 | $ 127,867 | |
| Net proceeds | $ 66,685 | $ 66,685 | ||
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- Definition Amount of asset recognized for present right to economic benefit. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of cash and cash equivalent. Cash includes, but is not limited to, currency on hand, demand deposit with financial institution, and account with general characteristic of demand deposit. Cash equivalent includes, but is not limited to, short-term, highly liquid investment that is both readily convertible to known amount of cash and so near maturity that it presents insignificant risk of change in value because of change in interest rate. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Cost of the investment. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Fair value of investment in security owned. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of liability recognized for present obligation requiring transfer or otherwise providing economic benefit to others. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of liabilities and equity items, including the portion of equity attributable to noncontrolling interests, if any. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of ownership interest in limited liability company (LLC), attributable to the parent entity. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of assets classified as other. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of liabilities classified as other. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The net cash inflow or outflow in aggregate debt due to repayments and proceeds from additional borrowings. No definition available.
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- Definition Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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