v3.25.2
Fair Value of Financial Instruments - Schedule of Fair Value Hierarchy of Investments (Details) - USD ($)
$ in Thousands
Jun. 30, 2025
Dec. 31, 2024
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Cash (including restricted and foreign cash) $ 170,523 $ 257,000
Total Investments at fair value 12,728,642 6,407,466
Foreign currency forward contracts    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivatives: (11,400)  
First-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 9,924,118 4,456,838
Second-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 426,937 258,538
Unsecured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 451,319 336,635
Preferred equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 1,022,197 689,952
Common equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 893,578 664,556
Interest rate swaps    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivatives: 28,822  
Level 1    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Cash (including restricted and foreign cash) 170,523 257,000
Total Investments at fair value 465 49,334
Level 1 | Foreign currency forward contracts    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivatives: 0  
Level 1 | First-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 0 0
Level 1 | Second-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 0 0
Level 1 | Unsecured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 0 0
Level 1 | Preferred equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 0 0
Level 1 | Common equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 465 49,334
Level 1 | Interest rate swaps    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivatives: 0  
Level 2    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 528,984 220,986
Level 2 | Foreign currency forward contracts    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivatives: (11,400)  
Level 2 | First-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 375,351 110,529
Level 2 | Second-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 116,649 92,379
Level 2 | Unsecured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 0 0
Level 2 | Preferred equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 0 0
Level 2 | Common equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 36,984 18,078
Level 2 | Interest rate swaps    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivatives: 28,822  
Level 3    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 12,076,329 6,074,522
Level 3 | Foreign currency forward contracts    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivatives: 0  
Level 3 | First-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 9,548,767 4,346,309
Level 3 | Second-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 310,288 166,159
Level 3 | Unsecured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 451,319 336,635
Level 3 | Preferred equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 1,022,197 689,952
Level 3 | Common equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 743,758 535,467
Level 3 | Interest rate swaps    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivatives: 0  
Levels 1, Level 2, and Level 3    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 12,605,778 6,344,842
Levels 1, Level 2, and Level 3 | First-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 9,924,118 4,456,838
Levels 1, Level 2, and Level 3 | Second-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 426,937 258,538
Levels 1, Level 2, and Level 3 | Unsecured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 451,319 336,635
Levels 1, Level 2, and Level 3 | Preferred equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 1,022,197 689,952
Levels 1, Level 2, and Level 3 | Common equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value 781,207 602,879
Investments measured at Net Asset Value    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Total Investments at fair value $ 122,864 $ 62,624