Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE HIERARCHY FOR INVESTMENTS???PORTFOLIO COMPOSITION - Narrative (Details)

v3.23.3
FAIR VALUE HIERARCHY FOR INVESTMENTS—PORTFOLIO COMPOSITION - Narrative (Details)
$ in Thousands
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2023
USD ($)
entity
company
Sep. 30, 2022
Sep. 30, 2023
USD ($)
entity
company
Sep. 30, 2022
Sep. 30, 2023
USD ($)
entity
company
Dec. 31, 2022
USD ($)
company
entity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Annualized total return on investments 0.120 0.105 0.129 0.086    
Achieved total return on investments           0.091
Fair value $ 1,103,813 [1]   $ 1,103,813 [1]   $ 1,103,813 [1] $ 1,068,143 [2]
Cost $ 1,065,140 [3]   $ 1,065,140 [3]   $ 1,065,140 [3] $ 1,059,886 [4]
Investment Owned, At Fair Value | Investment Type Concentration Risk            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Concentration risk, percentage     100.00%     100.00%
Investment Owned, At Cost | Investment Type Concentration Risk            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Concentration risk, percentage     100.00%     100.00%
Private Loan portfolio investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Number of portfolio companies | company 78   78   78 70
Fair value $ 609,000   $ 609,000   $ 609,000 $ 559,800
Cost 611,300   $ 611,300   $ 611,300 $ 563,000
Private Loan portfolio investments | Investment Owned, At Fair Value | Investment Type Concentration Risk            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Concentration risk, percentage     21.00% 18.00% 79.00%  
Private Loan portfolio investments | Debt investments | Investment Owned, At Cost | Investment Type Concentration Risk            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Concentration risk, percentage     95.90%     96.20%
Private Loan portfolio investments | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investments, per company 1,000   $ 1,000   $ 1,000  
Private Loan portfolio investments | Minimum | Debt investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment, term     3 years      
Private Loan portfolio investments | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investments, per company $ 20,000   $ 20,000   $ 20,000  
Private Loan portfolio investments | Maximum | Debt investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment, term     7 years      
LMM portfolio investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Number of portfolio companies | company 49   49   49 48
Fair value $ 367,600   $ 367,600   $ 367,600 $ 352,700
Cost 301,400   $ 301,400   $ 301,400 $ 312,500
LMM portfolio investments | Investment Owned, At Fair Value | Investment Type Concentration Risk            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Concentration risk, percentage     25.00% 25.00% 95.00%  
LMM portfolio investments | Debt investments | Investment Owned, At Cost | Investment Type Concentration Risk            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Concentration risk, percentage     70.10%     73.20%
LMM portfolio investments | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investments, per company 1,000   $ 1,000   $ 1,000  
Investments, annual revenues per company     $ 10,000      
LMM portfolio investments | Minimum | Debt investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment, term     5 years      
LMM portfolio investments | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investments, per company $ 20,000   $ 20,000   $ 20,000  
Investments, annual revenues per company     $ 150,000      
LMM portfolio investments | Maximum | Debt investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment, term     7 years      
Middle Market portfolio investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Number of portfolio companies | company 18   18   18 21
Fair value $ 101,100   $ 101,100   $ 101,100 $ 126,700
Cost 130,000   $ 130,000   130,000 $ 159,700
Middle Market portfolio investments | Debt investments | Investment Owned, At Cost | Investment Type Concentration Risk            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Concentration risk, percentage     93.90%     95.00%
Middle Market portfolio investments | Minimum            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investments, per company 1,000   $ 1,000   1,000  
Investments, annual revenues per company     $ 150,000      
Middle Market portfolio investments | Minimum | Debt investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment, term     3 years      
Middle Market portfolio investments | Maximum            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investments, per company $ 20,000   $ 20,000   $ 20,000  
Investments, annual revenues per company     $ 1,500,000      
Middle Market portfolio investments | Maximum | Debt investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment, term     7 years      
Other Portfolio investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Number of portfolio companies | entity 4   4   4 4
Fair value $ 26,200   $ 26,200   $ 26,200 $ 29,000
Cost $ 22,400   $ 22,400   $ 22,400 $ 24,700
Other Portfolio investments | Investment Owned, At Fair Value | Investment Type Concentration Risk            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Concentration risk, percentage     2.40%     2.70%
Other Portfolio investments | Investment Owned, At Cost | Investment Type Concentration Risk            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Concentration risk, percentage     2.10%     2.30%
Other Portfolio investments | Minimum | Debt investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment, term     5 years      
Other Portfolio investments | Maximum | Debt investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment, term     10 years      
[1] Investment fair value was determined using significant unobservable inputs, unless otherwise noted. See Note C—Fair Value Hierarchy for Investments—Portfolio Composition for further discussion. Negative fair value is the result of the capitalized discount on the loan or the unfunded commitment being valued below par.
[2] Investment fair value was determined using significant unobservable inputs, unless otherwise noted. See Note C — Fair Value Hierarchy for Investments—Portfolio Composition for further discussion. Negative fair value is the result of the capitalized discount on the loan or the unfunded commitment being valued below par.
[3] Principal is net of repayments. Cost is net of repayments and accumulated unearned income. Negative cost is the result of the capitalized discount being greater than the principal amount outstanding on the loan.
[4] Principal is net of repayments. Cost is net of repayments and accumulated unearned income.