v3.23.3

Audit Information	12 Months Ended
	Sep. 30, 2023
Audit Information [Abstract]
Auditor Name	Ernst & Young LLP
Auditor Location	Los Angeles, CA
Auditor Firm ID	42

X

- Definition

PCAOB issued Audit Firm Identifier

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 10-K
-Number 249
-Section 310

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 20-F
-Number 249
-Section 220
-Subsection f

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 40-F
-Number 249
-Section 240
-Subsection f

+ Details

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Namespace Prefix:	dei_
Data Type:	dei:nonemptySequenceNumberItemType
Balance Type:	na
Period Type:	duration

X

- References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 10-K
-Number 249
-Section 310

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 20-F
-Number 249
-Section 220
-Subsection f

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 40-F
-Number 249
-Section 240
-Subsection f

+ Details

Name:	dei_AuditorLocation
Namespace Prefix:	dei_
Data Type:	dei:internationalNameItemType
Balance Type:	na
Period Type:	duration

X

- References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 10-K
-Number 249
-Section 310

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 20-F
-Number 249
-Section 220
-Subsection f

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 40-F
-Number 249
-Section 240
-Subsection f

+ Details

Name:	dei_AuditorName
Namespace Prefix:	dei_
Data Type:	dei:internationalNameItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Audit Information [Abstract]

+ References

No definition available.

+ Details

Name:	ocsl_AuditInformationAbstract
Namespace Prefix:	ocsl_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration