v3.25.2

Fee Income (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2025 | Jun. 30, 2024
Revenue from Contract with Customer [Abstract] |  |  |  |
Fee income | $ 286 | $ 1,460 | $ 3,707 | $ 5,313
Recurring fee income | $ 100 | $ 200 | $ 200 | $ 500

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- Definition Fee Income, Recurring + References No definition available. + Details
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Namespace Prefix: | ocsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- Definition Amount of fee income including, but not limited to, managerial assistance, servicing of investment, and origination and commitment fees. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(1)(c)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1 + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- References No definition available. + Details
Name: | us-gaap_RevenueFromContractWithCustomerAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration