v3.26.3
Fair Value Measurement - Summary of Fair Value of the Company's Investments (Detail) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value $ 4,751,045 $ 3,008,628
Liabilities at Fair Value 12,673  
Interest Rate Swap [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Liabilities at Fair Value 12,673  
Practical Expedient [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value 68,353 49,937
First Lien Senior Secured [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value 4,585,380 2,903,414
Collateralized Loan Obligations [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value 94,435  
Second Lien Senior Secured [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value   5,460
Subordinated Notes [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value   49,318
Preferred Equity [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value 0 [1] 499
Unlisted Common Stock [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value 2,877  
Limited Partnership Interests [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value 68,353 49,937
Limited Partnership Interests [Member] | Practical Expedient [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value 68,353 49,937
Fair Value, Inputs, Level 3 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value 4,682,692 2,958,691
Fair Value, Inputs, Level 3 [Member] | First Lien Senior Secured [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value 4,585,380 2,903,414
Fair Value, Inputs, Level 3 [Member] | Collateralized Loan Obligations [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value 94,435  
Fair Value, Inputs, Level 3 [Member] | Second Lien Senior Secured [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value   5,460
Fair Value, Inputs, Level 3 [Member] | Subordinated Notes [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value   49,318
Fair Value, Inputs, Level 3 [Member] | Preferred Equity [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value 0 [1] $ 499
Fair Value, Inputs, Level 3 [Member] | Unlisted Common Stock [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair Value 2,877  
Fair Value, Inputs, Level 2 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Liabilities at Fair Value 12,673  
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Liabilities at Fair Value $ 12,673  
[1] Includes an investment with a fair value of 0.