v3.26.1
INVESTMENTS - Valuation Inputs (Details)
$ in Thousands
 6 Months Ended
Jun. 30, 2026
USD ($)
investment
Jun. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
investment
Schedule of Investments [Line Items]      
Fair value $ 2,458,590   $ 2,398,524
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Net unrealized appreciation (depreciation) on investments Net unrealized appreciation (depreciation) on investments  
Unrealized gain (loss) $ (27,300) $ 34,000  
Purchases of portfolio investments 368,859 409,178  
Senior debt and 1st lien notes      
Schedule of Investments [Line Items]      
Fair value 1,725,708   1,676,334
Subordinated debt and 2nd lien notes      
Schedule of Investments [Line Items]      
Fair value 234,415   190,290
Equity shares      
Schedule of Investments [Line Items]      
Fair value 435,572   $ 436,466
Investments with No Previous Contractual Commitment to Provide Financing      
Schedule of Investments [Line Items]      
Purchases of portfolio investments 278,500 355,300  
Investment with Previous Commitment to Provide Financing      
Schedule of Investments [Line Items]      
Purchases of portfolio investments $ 92,300    
Investment, Excluding Short Term Investment, with Previous Commitment to Provide Financing      
Schedule of Investments [Line Items]      
Purchases of portfolio investments   $ 50,700  
Yield Analysis | Senior debt and 1st lien notes | Market Approach      
Schedule of Investments [Line Items]      
Number of investments | investment 3   7
Fair value $ 52,300   $ 31,700
Yield Analysis | Subordinated debt and 2nd lien notes | Market Approach      
Schedule of Investments [Line Items]      
Number of investments | investment 1    
Fair value $ 200    
Yield Analysis | Subordinated debt and 2nd lien notes | Expected Recovery      
Schedule of Investments [Line Items]      
Number of investments | investment 1    
Fair value $ 300    
Yield Analysis | Equity shares | Market Approach      
Schedule of Investments [Line Items]      
Number of investments | investment 1    
Yield Analysis | Equity shares | Black-Scholes      
Schedule of Investments [Line Items]      
Fair value $ 500    
Net Asset Approach | Equity shares | Yield Analysis      
Schedule of Investments [Line Items]      
Number of investments | investment 1    
Fair value $ 4,000    
Valuation, Unadjusted Prices From Independent Pricing Services And Independent Indicative Broker Quotes | Debt Securities, Structured Product Position | Yield Analysis      
Schedule of Investments [Line Items]      
Number of investments | investment 1    
Fair value $ 9,900    
Market Approach | Senior debt and 1st lien notes | Yield Analysis      
Schedule of Investments [Line Items]      
Number of investments | investment     2
Fair value     $ 5,800