v3.25.1
Investment Portfolio - Schedule of Investment Portfolio At Cost And Fair Value (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2025
Dec. 31, 2024
Schedule of Investments [Line Items]    
Notional Amount $ 14,690.0 $ 14,044.0
Fair Value $ 14,121.5 [1] $ 13,490.4 [2]
Percentage  of Portfolio | Customer Concentration Risk    
Schedule of Investments [Line Items]    
Percentage of Portfolio 100.00% 100.00%
Senior Secured Loans—First Lien    
Schedule of Investments [Line Items]    
Notional Amount $ 8,408.0 $ 7,995.0
Fair Value $ 8,206.0 $ 7,795.0
Senior Secured Loans—First Lien | Percentage  of Portfolio | Customer Concentration Risk    
Schedule of Investments [Line Items]    
Percentage of Portfolio 58.10% 57.80%
Senior Secured Loans—Second Lien    
Schedule of Investments [Line Items]    
Notional Amount $ 692.0 $ 690.0
Fair Value $ 683.0 $ 693.0
Senior Secured Loans—Second Lien | Percentage  of Portfolio | Customer Concentration Risk    
Schedule of Investments [Line Items]    
Percentage of Portfolio 4.80% 5.10%
Other Senior Secured Debt    
Schedule of Investments [Line Items]    
Notional Amount $ 68.0 $ 130.0
Fair Value $ 62.0 $ 123.0
Other Senior Secured Debt | Percentage  of Portfolio | Customer Concentration Risk    
Schedule of Investments [Line Items]    
Percentage of Portfolio 0.40% 0.90%
Subordinated Debt    
Schedule of Investments [Line Items]    
Notional Amount $ 207.0 $ 214.0
Fair Value $ 242.0 $ 233.0
Subordinated Debt | Percentage  of Portfolio | Customer Concentration Risk    
Schedule of Investments [Line Items]    
Percentage of Portfolio 1.70% 1.70%
Asset Based Finance    
Schedule of Investments [Line Items]    
Notional Amount $ 2,299.0 $ 2,232.0
Fair Value $ 2,170.0 $ 2,102.0
Asset Based Finance | Percentage  of Portfolio | Customer Concentration Risk    
Schedule of Investments [Line Items]    
Percentage of Portfolio 15.40% 15.60%
Credit Opportunities Partners JV, LLC    
Schedule of Investments [Line Items]    
Notional Amount $ 1,869.0 $ 1,572.0
Fair Value $ 1,661.0 $ 1,363.0
Credit Opportunities Partners JV, LLC | Percentage  of Portfolio | Customer Concentration Risk    
Schedule of Investments [Line Items]    
Percentage of Portfolio 11.80% 10.10%
Equity/Other    
Schedule of Investments [Line Items]    
Notional Amount $ 1,147.0 $ 1,211.0
Fair Value $ 1,098.0 $ 1,181.0
Equity/Other | Percentage  of Portfolio | Customer Concentration Risk    
Schedule of Investments [Line Items]    
Percentage of Portfolio 7.80% 8.80%
[1] See Note 8 for additional information regarding the fair value of the Company’s financial instruments.
[2] See Note 8 for additional information regarding the fair value of the Company’s financial instruments.