v3.25.2
Investment Portfolio - Narrative (Details)
$ in Millions
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2025
USD ($)
company
Jun. 30, 2024
USD ($)
Jun. 30, 2025
USD ($)
company
Jun. 30, 2024
USD ($)
Dec. 31, 2024
USD ($)
company
Schedule of Investments [Line Items]          
Amount funded to joint venture     $ 2,140.0    
Net realized gain (loss) on investments:     (153.0) $ (307.0)  
Receivable for investments sold and repaid $ 320.0   320.0   $ 186.0
Credit Opportunities Partners JV, LLC          
Schedule of Investments [Line Items]          
Aggregate credit opportunities partners     2,800.0    
Cost basis of investments sold     836.6    
Proceeds from sale of investments     850.5    
Net realized gain (loss) on investments:     13.9    
Receivable for investments sold and repaid 355.4   $ 355.4    
Credit opportunities partners JV, LLC, entitled to a fee percentage     0.25%    
Administrative services 2.8 $ 2.3 $ 5.1 4.7  
FS KKR Capital Corp.          
Schedule of Investments [Line Items]          
Contributed capital to committed capital ratio     87.50%    
Joint venture voting control, percentage     50.00%    
Amount funded to joint venture     $ 1,872.5    
SCRS          
Schedule of Investments [Line Items]          
Contributed capital to committed capital ratio     12.50%    
Joint venture voting control, percentage     50.00%    
Unfunded Debt Securities          
Schedule of Investments [Line Items]          
Unfunded commitments 1,730.1   $ 1,730.1   1,534.1
Unfunded Equity/Other Commitments          
Schedule of Investments [Line Items]          
Unfunded commitments $ 369.7   $ 369.7   387.1
Partnership Interest          
Schedule of Investments [Line Items]          
Unfunded commitments         $ 735.2
Controlled/affiliated          
Schedule of Investments [Line Items]          
Number of investments in portfolio companies | company 32   32   31
Net realized gain (loss) on investments: $ (68.0) (1.0) $ (54.7) (9.0) $ 23.2
Non-controlled/affiliated          
Schedule of Investments [Line Items]          
Number of investments in portfolio companies | company 11   11   11
Net realized gain (loss) on investments: $ (1.0) $ 2.0 $ 8.4 $ (8.0) $ (60.7)