v3.25.4
Investments (Details) - USD ($)
12 Months Ended
Nov. 18, 2025
Mar. 19, 2025
Dec. 27, 2024
Dec. 31, 2025
Dec. 31, 2024
Dec. 18, 2024
Schedule of Equity Method Investments [Line Items]            
Capital commitments       $ 300,000,000    
Investments       0    
Investments at fair value       1,681,258,000 $ 717,299,000  
Maximum borrowing capacity           $ 575,000,000
Subordinated Debt            
Schedule of Equity Method Investments [Line Items]            
Investments at fair value       103,961,000 5,147,000  
Preferred Equity            
Schedule of Equity Method Investments [Line Items]            
Investments at fair value       24,362,000 14,694,000  
Equity Interests            
Schedule of Equity Method Investments [Line Items]            
Investments at fair value       37,894,000 $ 10,984,000  
Bain Capital Senior Loan Program II, LLC            
Schedule of Equity Method Investments [Line Items]            
Investments sold       148,700,000    
Bain Capital Senior Loan Program II, LLC | MM CLO WH 1 Credit Facility            
Schedule of Equity Method Investments [Line Items]            
Maximum borrowing capacity   $ 100,000,000        
Spread rate (as a percent)   200.00%        
Effective interest rate   6.10%        
Line of credit facility expiration date   Mar. 19, 2029        
Outstanding balance       98,300,000    
Bain Capital Senior Loan Program II, LLC | Subordinated Debt            
Schedule of Equity Method Investments [Line Items]            
Investments at fair value       20,200,000    
Bain Capital Senior Loan Program II, LLC | Preferred Equity            
Schedule of Equity Method Investments [Line Items]            
Investments at fair value       100,000    
Bain Capital Senior Loan Program II, LLC | Equity Interests            
Schedule of Equity Method Investments [Line Items]            
Investments at fair value       $ 7,000,000    
Amberstone Co., Ltd.            
Schedule of Equity Method Investments [Line Items]            
Ownership Percentage     50.00%      
Capital commitments $ 100,000,000   $ 100,000,000