Investment Company, Financial Commitment to Investee, Unrealized Appreciation (Depreciation)

No definition available.

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Namespace Prefix:	fsk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of financial support committed by investment company to investee that is contractually required but not provided.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-16

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Commitments and Contingencies - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Aug. 09, 2018
Letter of Credit \| Senior Secured Revolving Credit Facility \| Line of Credit
Other Commitments [Line Items]
Amount outstanding	$ 175.0		$ 175.0
Letters of credit	21.0
Debt Securities, Revolving Credit Facility
Other Commitments [Line Items]
Unfunded commitments	708.7
Debt Securities, Delayed Draw Term Loan
Other Commitments [Line Items]
Unfunded commitments	825.4
Debt Securities
Other Commitments [Line Items]
Unrealized appreciation (depreciation) on unfunded commitments	(1.7)
Partnership Interest
Other Commitments [Line Items]
Unfunded commitments	735.2	$ 560.2
Partnership Interest \| Credit Opportunities Partners JV, LLC
Other Commitments [Line Items]
Unfunded commitments	$ 735.2