v3.26.1
Investment Portfolio - Narrative (Details)
$ in Millions
 3 Months Ended 12 Months Ended
Feb. 23, 2026
USD ($)
Mar. 31, 2026
USD ($)
company
Mar. 31, 2025
USD ($)
Dec. 31, 2025
USD ($)
company
Schedule of Investments [Line Items]        
Amount funded to joint venture   $ 2,520.0    
Net realized gain (loss) on investments:   (195.0) $ (18.0)  
Receivable for investments sold and repaid   263.0   $ 313.0
Credit Opportunities Partners JV, LLC        
Schedule of Investments [Line Items]        
Cost basis of investments sold $ 189.0 0.0   1,805.4
Aggregate credit opportunities partners 175.0      
Amount funded to joint venture 2,975.0      
Proceeds from sale of investments   0.0   1,829.2
Net realized gain (loss) on investments:   0.0   23.8
Receivable for investments sold and repaid   $ 180.1    
Credit opportunities partners JV, LLC, entitled to a fee percentage   0.25%    
Administrative services   $ 3.1 2.3  
FS KKR Capital Corp.        
Schedule of Investments [Line Items]        
Joint venture voting control, percentage   50.00%    
Amount funded to joint venture $ 2,450.0 $ 2,016.0    
Contributed capital to committed capital ratio 79.00%      
SCRS        
Schedule of Investments [Line Items]        
Joint venture voting control, percentage   50.00%    
Amount funded to joint venture $ 525.0      
Contributed capital to committed capital ratio 21.00%      
Credit Opportunities Partners JV, LLC        
Schedule of Investments [Line Items]        
Unfunded commitments   $ 434.0   245.0
Unfunded Debt Securities        
Schedule of Investments [Line Items]        
Unfunded commitments   1,326.0   1,447.4
Unfunded Equity/Other Commitments        
Schedule of Investments [Line Items]        
Unfunded commitments   $ 87.2   $ 87.5
Controlled/affiliated        
Schedule of Investments [Line Items]        
Number of investments in portfolio companies | company   37   34
Net realized gain (loss) on investments:   $ (55.7) 13.0 $ (73.7)
Non-controlled/affiliated        
Schedule of Investments [Line Items]        
Number of investments in portfolio companies | company   9   10
Net realized gain (loss) on investments:   $ (98.0) $ 9.0 $ (2.3)