v3.26.3
Financing Arrangements - Narrative (Details) - USD ($)
$ in Millions
9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Jun. 15, 2019
Jun. 14, 2019
Debt Instrument [Line Items]          
Asset coverage per ratio (as percent) 179.00%        
Long term outstanding $ 6,487 $ 7,369 $ 7,620    
Senior securities, asset coverage ratio (as percent) 177.00% 184.00%      
Average outstanding amount $ 7,104 $ 8,174      
Weighted average interest rate (as percent) 5.72% 5.48%      
Investment Advisory Agreement | FS/KKR Advisor, LLC          
Debt Instrument [Line Items]          
Asset coverage per ratio (as percent)       150.00% 200.00%