Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE HIERARCHY FOR INVESTMENTS???PORTFOLIO COMPOSITION - Schedule of Investments (Details)

v3.23.3
FAIR VALUE HIERARCHY FOR INVESTMENTS—PORTFOLIO COMPOSITION - Schedule of Investments (Details)
$ in Thousands
 9 Months Ended 12 Months Ended
Sep. 30, 2023
USD ($)
company
Dec. 31, 2022
USD ($)
company
Summary of Investment Holdings [Line Items]    
Fair value $ 1,103,813 [1] $ 1,068,143 [2]
Cost $ 1,065,140 [3] $ 1,059,886 [4]
Investment Owned, At Cost | Investment Type Concentration Risk    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 100.00% 100.00%
Investment Owned, At Cost | Investment Type Concentration Risk | Nonperforming Financial Instruments    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 5.20% 4.80%
Investment Owned, At Cost | Investment Type Concentration Risk | Equity investments    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 11.70% 10.80%
Investment Owned, At Cost | Investment Type Concentration Risk | First lien debt    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 87.70% 88.50%
Private Loan portfolio investments    
Summary of Investment Holdings [Line Items]    
Number of portfolio companies | company 78 70
Fair value $ 609,000 $ 559,800
Cost $ 611,300 $ 563,000
Total Rate 13.10% 11.80%
Average EBITDA $ 32,600 $ 36,800
Investment company, number of companies within portfolio excluded from EBITDA calculation | company 1 1
Private Loan portfolio investments | Nonperforming Financial Instruments    
Summary of Investment Holdings [Line Items]    
Total Rate 12.30% 11.40%
Private Loan portfolio investments | Investment Owned, At Cost | Investment Type Concentration Risk | Debt investments    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 95.90% 96.20%
Private Loan portfolio investments | Investment Owned, At Cost | Investment Type Concentration Risk | Equity investments    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 4.10% 3.80%
Private Loan portfolio investments | Investment Owned, At Cost | Investment Type Concentration Risk | First lien debt    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 99.40% 99.40%
LMM portfolio investments    
Summary of Investment Holdings [Line Items]    
Number of portfolio companies | company 49 48
Fair value $ 367,600 $ 352,700
Cost $ 301,400 $ 312,500
Total Rate 12.90% 12.10%
Average EBITDA $ 8,600 $ 8,600
Diluted equity ownership percentage 9.00% 9.00%
LMM portfolio investments | Nonperforming Financial Instruments    
Summary of Investment Holdings [Line Items]    
Total Rate 12.90% 11.70%
LMM portfolio investments | Investment Owned, At Cost | Investment Type Concentration Risk | Debt investments    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 70.10% 73.20%
LMM portfolio investments | Investment Owned, At Cost | Investment Type Concentration Risk | Equity investments    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 29.90% 26.80%
LMM portfolio investments | Investment Owned, At Cost | Investment Type Concentration Risk | First lien debt    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 100.00% 99.90%
Middle Market portfolio investments    
Summary of Investment Holdings [Line Items]    
Number of portfolio companies | company 18 21
Fair value $ 101,100 $ 126,700
Cost $ 130,000 $ 159,700
Total Rate 12.80% 11.30%
Average EBITDA $ 74,600 $ 79,200
Middle Market portfolio investments | Nonperforming Financial Instruments    
Summary of Investment Holdings [Line Items]    
Total Rate 10.20% 9.70%
Middle Market portfolio investments | Investment Owned, At Cost | Investment Type Concentration Risk | Debt investments    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 93.90% 95.00%
Middle Market portfolio investments | Investment Owned, At Cost | Investment Type Concentration Risk | Equity investments    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 6.10% 5.00%
Middle Market portfolio investments | Investment Owned, At Cost | Investment Type Concentration Risk | First lien debt    
Summary of Investment Holdings [Line Items]    
Concentration risk, percentage 100.00% 98.50%
[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.