Quarterly report pursuant to Section 13 or 15(d)

INVESTMENTS - Narrative (Details)

v3.24.0.1
INVESTMENTS - Narrative (Details)
$ in Thousands
 1 Months Ended 3 Months Ended 6 Months Ended 9 Months Ended
Oct. 31, 2023
USD ($)
Sep. 30, 2023
USD ($)
Aug. 31, 2023
USD ($)
Jun. 30, 2023
USD ($)
May 31, 2023
USD ($)
Dec. 31, 2023
USD ($)
portfolioCompany
industry
state
Dec. 31, 2022
USD ($)
Sep. 30, 2022
USD ($)
Sep. 30, 2022
USD ($)
Dec. 31, 2023
USD ($)
portfolioCompany
industry
state
Dec. 31, 2022
USD ($)
Mar. 31, 2023
USD ($)
Summary of Investment Holdings [Line Items]                        
Purchase of investments                   $ 182,988 $ 133,506  
Dividend income           $ 0 $ 4,466     1,907 10,847  
Cost           868,504       868,504   $ 720,630 [1]
Success fee income           $ 1,382 $ 1,061     1,382 7,794  
Principal repayments of investments                   $ 27,500 $ 50,300  
Number of investment portfolio company | portfolioCompany           25       25    
Number of states which have invested in the company location | state           18       18    
Number of industries that have made investments | industry           16       16    
Fair Value           $ 902,808       $ 902,808   753,543 [1]
Uncollectible receivables allowance, minimum required day for uncollectible adjustment                   90 days    
Gross receivables from portfolio companies           2,300       $ 2,300   2,200
Allowance for uncollectible receivables           1,600       1,600    
Five Largest Portfolio Investments | Investment Portfolio Benchmark | Customer Concentration Risk                        
Summary of Investment Holdings [Line Items]                        
Fair Value           380,900       $ 380,900    
Concentration risk, percentage                   42.20%    
Secured First Lien Debt                        
Summary of Investment Holdings [Line Items]                        
Cost           517,539       $ 517,539   471,439
Fair Value           476,126       476,126   437,517
Preferred Equity                        
Summary of Investment Holdings [Line Items]                        
Cost           151,969       151,969   149,099
Fair Value           214,664       214,664   222,585
Secured Second Lien Debt                        
Summary of Investment Holdings [Line Items]                        
Cost           148,158       148,158   84,158
Fair Value           137,480       137,480   75,734
Common Equity/ Equivalents                        
Summary of Investment Holdings [Line Items]                        
Cost           50,838       50,838   15,934
Fair Value           $ 74,538       74,538   $ 17,707
Home Concepts Acquisition, Inc                        
Summary of Investment Holdings [Line Items]                        
Purchase of investments         $ 15,300              
Home Concepts Acquisition, Inc | Secured First Lien Debt                        
Summary of Investment Holdings [Line Items]                        
Purchase of investments         12,000              
Home Concepts Acquisition, Inc | Preferred Equity                        
Summary of Investment Holdings [Line Items]                        
Purchase of investments         $ 3,300              
Old World Christmas, Inc.                        
Summary of Investment Holdings [Line Items]                        
Purchase of investments       $ 2,500                
Proceeds from equity       2,200                
Dividend income       1,900                
Realized gain on preferred equity       300       $ 13,400 $ 13,400 $ 300    
Nth Degree Investment Group, LLC                        
Summary of Investment Holdings [Line Items]                        
Purchase of investments       30,000                
Nth Degree Investment Group, LLC | Secured Second Lien Debt                        
Summary of Investment Holdings [Line Items]                        
Purchase of investments       25,000                
Nth Degree Investment Group, LLC | Common Equity/ Equivalents                        
Summary of Investment Holdings [Line Items]                        
Purchase of investments       5,000                
Specialty Knives & Tools, LLC                        
Summary of Investment Holdings [Line Items]                        
Realized gain on preferred equity       900                
Net proceeds from the sale of investments       1,500                
Cost       $ 600                
Nocturne Villa Rentals, Inc.                        
Summary of Investment Holdings [Line Items]                        
Purchase of investments     $ 18,700                  
The E3 Company, LLC                        
Summary of Investment Holdings [Line Items]                        
Purchase of investments   $ 46,000                    
The E3 Company, LLC | Secured First Lien Debt                        
Summary of Investment Holdings [Line Items]                        
Purchase of investments   34,800                    
The E3 Company, LLC | Preferred Equity                        
Summary of Investment Holdings [Line Items]                        
Purchase of investments   $ 11,200                    
SFEG Holdings, Inc                        
Summary of Investment Holdings [Line Items]                        
Purchase of investments $ 64,700                      
Cost 4,800                      
Fair Value 8,600                      
SFEG Holdings, Inc | Secured Second Lien Debt                        
Summary of Investment Holdings [Line Items]                        
Purchase of investments 39,000                      
SFEG Holdings, Inc | Common Equity/ Equivalents                        
Summary of Investment Holdings [Line Items]                        
Purchase of investments 25,700                      
Counsel Press, Inc.,                        
Summary of Investment Holdings [Line Items]                        
Realized gain on preferred equity 43,500                      
Success fee income 1,400                      
Principal repayments of investments $ 27,500                      
[1] Cumulative gross unrealized appreciation for federal income tax purposes is $150.4 million; cumulative gross unrealized depreciation for federal income tax purposes is $119.3 million. Cumulative net unrealized appreciation is $31.1 million, based on a tax cost of $722.4 million.