v3.26.1
Fair Value of Financial Instruments - Schedule of Fair Value Hierarchy of Investments (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Cash (including restricted and foreign cash) $ 488,163 $ 282,924
Fair Value 14,068,239 14,286,039
Foreign currency forward contracts    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivative assets 9,886  
Derivative liabilities   1,941
First-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 10,917,188 10,979,070
Second-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 498,121 568,641
Unsecured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 456,403 477,128
Specialty finance debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 38,000 37,452
Preferred equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 982,150 1,072,481
Common equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 615,910 722,100
Specialty finance equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 527,414 375,812
Interest rate swaps    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivative assets 15,744 26,732
Derivative liabilities 938  
Level 1    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Cash (including restricted and foreign cash) 488,163 282,924
Fair Value 419 706
Level 1 | Foreign currency forward contracts    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivative assets 0  
Derivative liabilities   0
Level 1 | First-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
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]    
Fair Value 0 0
Level 1 | Unsecured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 0 0
Level 1 | Specialty finance debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 0 0
Level 1 | Preferred equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 0 0
Level 1 | Common equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 419 706
Level 1 | Specialty finance equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 0 0
Level 1 | Interest rate swaps    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivative assets 0 0
Derivative liabilities 0  
Level 2    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 450,039 481,386
Level 2 | Foreign currency forward contracts    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivative assets 9,886  
Derivative liabilities   1,941
Level 2 | First-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 300,333 318,098
Level 2 | Second-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 120,520 125,924
Level 2 | Unsecured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 0 0
Level 2 | Specialty finance debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 0 0
Level 2 | Preferred equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 0 0
Level 2 | Common equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 29,186 37,364
Level 2 | Specialty finance equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 0 0
Level 2 | Interest rate swaps    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivative assets 15,744 26,732
Derivative liabilities 938  
Level 3    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 13,205,096 13,590,644
Level 3 | Foreign currency forward contracts    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivative assets 0  
Derivative liabilities   0
Level 3 | First-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 10,616,855 10,660,972
Level 3 | Second-lien senior secured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 377,601 442,717
Level 3 | Unsecured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 456,403 477,128
Level 3 | Specialty finance debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 38,000 37,452
Level 3 | Preferred equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 982,150 1,072,481
Level 3 | Common equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 564,590 684,030
Level 3 | Specialty finance equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 169,497 215,864
Level 3 | Interest rate swaps    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Derivative assets 0 0
Derivative liabilities 0  
Levels 1, Level 2, and Level 3    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 13,655,554 14,072,736
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]    
Fair Value 10,917,188 10,979,070
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]    
Fair Value 498,121 568,641
Levels 1, Level 2, and Level 3 | Unsecured debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 456,403 477,128
Levels 1, Level 2, and Level 3 | Specialty finance debt investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 38,000 37,452
Levels 1, Level 2, and Level 3 | Preferred equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 982,150 1,072,481
Levels 1, Level 2, and Level 3 | Common equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 594,195 722,100
Levels 1, Level 2, and Level 3 | Specialty finance equity investments    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value 169,497 215,864
Investments measured at NAV    
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]    
Fair Value $ 412,685 $ 213,303