v3.25.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)
$ in Millions
3 Months Ended 12 Months Ended 49 Months Ended
Mar. 31, 2025
USD ($)
company
segment
Mar. 31, 2024
company
Mar. 31, 2025
USD ($)
company
Dec. 31, 2024
USD ($)
Mar. 31, 2025
USD ($)
Schedule of Investments [Line Items]          
Concentration risk, percentage (as a percent) 100.00%     100.00%  
Cash equivalents | $ $ 15.5   $ 15.5 $ 14.4 $ 15.5
Cash balances exceeded federal deposit insurance corporation insurance protection levels | $ $ 22.8   $ 22.8 $ 13.5 $ 22.8
Percentage of total investment income, attributable to noncash paid-in-kind interest income (as a percent) 5.80% 4.50%      
Percentage of total investment income, attributable to noncash cumulative dividend income (as a percent) 0.20% 0.10%      
Percentage of total investment income, attributable to interest income, debt investments, net (as a percent) 2.30% 2.50%      
Number of reportable segments | segment 1        
Investment Owned, At Fair Value | Investment Type Concentration Risk          
Schedule of Investments [Line Items]          
Concentration risk, percentage (as a percent) 100.00%     100.00%  
Investment Owned, At Fair Value | Investment Type Concentration Risk | Nonperforming Financial Instruments          
Schedule of Investments [Line Items]          
Concentration risk, percentage (as a percent) 2.80%     1.50%  
Investment Owned, At Cost | Investment Type Concentration Risk          
Schedule of Investments [Line Items]          
Concentration risk, percentage (as a percent) 100.00%     100.00%  
Investment Owned, At Cost | Investment Type Concentration Risk | Nonperforming Financial Instruments          
Schedule of Investments [Line Items]          
Concentration risk, percentage (as a percent) 6.10%     5.60%  
Private Loan portfolio investments          
Schedule of Investments [Line Items]          
Consultation period subsequent to initial investment 12 months        
Investment company, number of portfolio companies with annual third-party appraisal was obtained, reviewed and certified | company 13 14 63    
Percentage of portfolio with annual third-party appraisal was obtained, reviewed and certified (as a percent)         96.00%
Private Loan portfolio investments | Investment Owned, At Fair Value | Investment Type Concentration Risk          
Schedule of Investments [Line Items]          
Concentration risk, percentage (as a percent) 26.00% 21.00% 88.00%    
LMM portfolio investments          
Schedule of Investments [Line Items]          
Consultation period subsequent to initial investment 12 months        
Investment company, number of portfolio companies with annual third-party appraisal was obtained, reviewed and certified | company 12 12 48    
Percentage of portfolio with annual third-party appraisal was obtained, reviewed and certified (as a percent)     99.00%    
LMM portfolio investments | Investment Owned, At Fair Value | Investment Type Concentration Risk          
Schedule of Investments [Line Items]          
Concentration risk, percentage (as a percent) 26.00% 26.00% 95.00%    
Middle Market portfolio investments          
Schedule of Investments [Line Items]          
Percentage of portfolio investments containing limited consultation with financial advisory services firm (as a percent) 91.00%   91.00% 93.00% 91.00%
Middle Market portfolio investments | Investment Owned, At Fair Value | Investment Type Concentration Risk          
Schedule of Investments [Line Items]          
Concentration risk, percentage (as a percent) 2.40%     3.30%  
Middle Market portfolio investments | Investment Owned, At Cost | Investment Type Concentration Risk          
Schedule of Investments [Line Items]          
Concentration risk, percentage (as a percent) 3.40%     5.80%  
Other Portfolio investments | Investment Owned, At Fair Value | Investment Type Concentration Risk          
Schedule of Investments [Line Items]          
Concentration risk, percentage (as a percent) 1.80%     2.00%  
Other Portfolio investments | Investment Owned, At Cost | Investment Type Concentration Risk          
Schedule of Investments [Line Items]          
Concentration risk, percentage (as a percent) 1.40%     1.60%