v3.26.3
FAIR VALUE OF FINANCIAL INSTRUMENTS - Schedule of Fair Value of Investments (Details) - USD ($)
Sep. 30, 2026
Dec. 31, 2025
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents $ 10,566,935,000 $ 3,120,386,000
Interest rate swap contracts (asset) 80,813,000 9,358,000
Interest rate swap contracts (liability) (941,000) (6,274,000)
Total 10,651,608,000 3,123,817,000
Common equity    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 6,516,384,000 2,168,096,000
Preferred equity    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 1,047,597,000  
Other equity    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 987,596,000 354,399,000
First lien senior secured loans    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 1,446,172,000 508,273,000
Senior subordinated loans    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 510,064,000 89,618,000
Corporate bonds    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 59,122,000  
Money market funds    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 4,801,000 347,000
Level 1    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Interest rate swap contracts (asset) 0 0
Interest rate swap contracts (liability) 0 0
Total 4,801,000 347,000
Level 1 | Common equity    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 0 0
Level 1 | Preferred equity    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 0  
Level 1 | Other equity    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 0 0
Level 1 | First lien senior secured loans    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 0 0
Level 1 | Senior subordinated loans    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 0 0
Level 1 | Corporate bonds    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 0  
Level 1 | Money market funds    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 4,801,000 347,000
Level 2    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Interest rate swap contracts (asset) 80,813,000 9,358,000
Interest rate swap contracts (liability) (941,000) (6,274,000)
Total 1,165,725,000 345,988,000
Level 2 | Common equity    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 0 0
Level 2 | Preferred equity    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 0  
Level 2 | Other equity    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 0 0
Level 2 | First lien senior secured loans    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 1,056,131,000 342,904,000
Level 2 | Senior subordinated loans    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 0 0
Level 2 | Corporate bonds    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 29,722,000  
Level 2 | Money market funds    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 0 0
Level 3    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 9,481,082,000 2,777,482,000
Interest rate swap contracts (asset) 0 0
Interest rate swap contracts (liability) 0 0
Total 9,481,082,000 2,777,482,000
Level 3 | Common equity    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 6,516,384,000 2,168,096,000
Level 3 | Preferred equity    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 1,047,597,000  
Level 3 | Other equity    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 987,596,000 354,399,000
Level 3 | First lien senior secured loans    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 390,041,000 165,369,000
Level 3 | Senior subordinated loans    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents 510,064,000 $ 89,618,000
Level 3 | Corporate bonds    
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]    
Investments and cash equivalents $ 29,400,000