Quarterly report pursuant to Section 13 or 15(d)

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)

v3.24.2.u1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)
$ in Millions
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2024
USD ($)
company
Jun. 30, 2023
company
Jun. 30, 2024
USD ($)
Jun. 30, 2023
Jun. 30, 2024
USD ($)
company
Dec. 31, 2023
USD ($)
Schedule of Investments [Line Items]            
Cash equivalents | $ $ 6.6   $ 6.6   $ 6.6 $ 15.2
Cash exceeded federal deposit insurance corporation insurance protection levels | $ $ 19.8   $ 19.8   $ 19.8 $ 40.1
Percentage of total investment income, attributable to noncash paid-in-kind interest income (as a percent) 3.70% 1.80% 3.50% 2.10%    
Percentage of total investment come, attributable to noncash cumulative dividend income (as a percent) 0.50% 0.20% 0.40% 0.30%    
Percentage of total investment income, attributable to interest income, debt investments, net (as a percent) 2.00% 1.80% 1.90% 1.80%    
Investment Owned, At Fair Value | Investment Type Concentration Risk            
Schedule of Investments [Line Items]            
Concentration risk (as a percent)     100.00%     100.00%
Investment Owned, At Cost | Investment Type Concentration Risk            
Schedule of Investments [Line Items]            
Concentration risk (as a percent)     100.00%     100.00%
Non-accrual Status | Investment Owned, At Fair Value | Investment Type Concentration Risk            
Schedule of Investments [Line Items]            
Concentration risk (as a percent)     1.20%     0.60%
Non-accrual Status | Investment Owned, At Cost | Investment Type Concentration Risk            
Schedule of Investments [Line Items]            
Concentration risk (as a percent)     3.60%     2.30%
Revolving Credit Facility | Line of Credit            
Schedule of Investments [Line Items]            
Commitment fee (as a percentage)     3.40%      
LMM portfolio investments            
Schedule of Investments [Line Items]            
Consultation period subsequent to initial investment (in months)     12 months      
Investment company, number of portfolio companies with annual third-party appraisal was obtained, reviewed and certified | company 18 18     70  
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 (as a percent) 21.00% 23.00%     94.00%  
Private Loan portfolio investments            
Schedule of Investments [Line Items]            
Consultation period subsequent to initial investment (in months)     12 months      
Investment company, number of portfolio companies with annual third-party appraisal was obtained, reviewed and certified | company 19 15     60  
Percentage of portfolio with annual third-party appraisal was obtained, reviewed and certified (as a percent)         95.00%  
Private Loan portfolio investments | Investment Owned, At Fair Value | Investment Type Concentration Risk            
Schedule of Investments [Line Items]            
Concentration risk (as a percent) 22.00% 24.00%     72.00%  
Middle Market portfolio investments            
Schedule of Investments [Line Items]            
Percentage of portfolio investments containing limited consultation with financial advisory services firm (as a percent) 98.00%   98.00%   98.00% 98.00%
Other Portfolio investments | Investment Owned, At Fair Value | Investment Type Concentration Risk            
Schedule of Investments [Line Items]            
Concentration risk (as a percent)     3.80%     3.30%
Other Portfolio investments | Investment Owned, At Cost | Investment Type Concentration Risk            
Schedule of Investments [Line Items]            
Concentration risk (as a percent)     4.30%     4.00%