Annual report pursuant to Section 13 and 15(d)

INVESTMENTS - Narrative (Details)

v3.23.3
INVESTMENTS - Narrative (Details)
$ in Thousands
 1 Months Ended 2 Months Ended 3 Months Ended 12 Months Ended
Sep. 30, 2023
USD ($)
state
investment
portfolioCompany
industry
Jul. 31, 2023
USD ($)
Jun. 30, 2023
USD ($)
May 31, 2023
USD ($)
Apr. 30, 2023
USD ($)
Mar. 31, 2023
USD ($)
Jan. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Oct. 31, 2022
USD ($)
Nov. 30, 2022
USD ($)
Mar. 31, 2023
USD ($)
Sep. 30, 2023
USD ($)
state
investment
portfolioCompany
industry
Sep. 30, 2022
USD ($)
investment
Sep. 30, 2021
USD ($)
Summary of Investment Holdings [Line Items]                            
Number of proprietary investments | investment 47                     47 46  
Investments, at fair value $ 704,815 [1]                     $ 704,815 [1] $ 649,615 [2]  
Purchase of investments                       175,477 274,898 $ 181,841
Line of credit commitment                       45,231 74,846  
Cost $ 722,269 [1]                     $ 722,269 [1] 656,053 [2]  
Number of investment portfolio company | portfolioCompany 51                     51    
Number of states which have invested in the company location | state 23                     23    
Number of industries that have made investments | industry 12                     12    
Weighted average investment owned, at cost, amount $ 14,200                     $ 14,200 12,600  
Uncollectible receivables allowance, minimum required day for uncollectible adjustment                       90 days    
Gross receivables from portfolio companies 800                     $ 800 500  
Allowance for uncollectible receivables 9                     9 0  
Leeds Novamark Capital I, L.P                            
Summary of Investment Holdings [Line Items]                            
Investments, at fair value 200                     200    
Proceeds from equity                   $ 6,000        
Realized investment gains                   $ 4,400        
R2i Holdings, LLC                            
Summary of Investment Holdings [Line Items]                            
Net proceeds from the sale of investments               $ 19,200            
NeoGraf Solutions, LLC                            
Summary of Investment Holdings [Line Items]                            
Purchase of investments             $ 29,000              
Line of credit commitment             $ 4,500              
Salt & Straw, LLC                            
Summary of Investment Holdings [Line Items]                            
Purchase of investments                     $ 6,300      
Leadpoint Business Services, LLC                            
Summary of Investment Holdings [Line Items]                            
Purchase of investments           $ 13,500                
Line of credit commitment           $ 5,500                
Funded line of credit       $ 5,500                    
Technical Resource Management, LLC                            
Summary of Investment Holdings [Line Items]                            
Purchase of investments         $ 25,000                  
Line of credit commitment         3,000                  
Investment company, delayed draw term loan commitment         2,500                  
HH-Inspire Acquisition, Inc.                            
Summary of Investment Holdings [Line Items]                            
Purchase of investments     $ 3,400   16,800                  
Cost         35,500                  
Investment company, prepayment fee         200                  
OCI, LLC                            
Summary of Investment Holdings [Line Items]                            
Purchase of investments       $ 22,000                    
PIC 360, LLC                            
Summary of Investment Holdings [Line Items]                            
Investments, at fair value     300                      
Realized investment gains     3,700                      
Trowbridge Chicago, LLC                            
Summary of Investment Holdings [Line Items]                            
Purchase of investments     6,500                      
Line of credit commitment     2,000                      
Investment company, delayed draw term loan commitment     5,300                      
Gray Matter Systems, LLC                            
Summary of Investment Holdings [Line Items]                            
Purchase of investments   $ 5,000                        
Sea Link International IRB, Inc                            
Summary of Investment Holdings [Line Items]                            
Purchase of investments 4,000                          
Antenna Research Associates, Inc                            
Summary of Investment Holdings [Line Items]                            
Purchase of investments 8,100                          
Encore Dredging Holdings, LLC                            
Summary of Investment Holdings [Line Items]                            
Investments, at fair value 4,300                     4,300    
Cost 3,800                     3,800    
Prepayment fee and early termination fees 400                          
Targus Cayman HoldCo Ltd.                            
Summary of Investment Holdings [Line Items]                            
Realized investment gains                 $ 5,900          
Net proceeds from the sale of investments                 8,000          
B. Riley Financial, Inc. – Term Debt                            
Summary of Investment Holdings [Line Items]                            
Net proceeds from the sale of investments     $ 2,400                      
Cost                 $ 2,400          
Investment, interest rate, paid in cash     6.75%           6.75%          
CPM Holdings, Inc                            
Summary of Investment Holdings [Line Items]                            
Net proceeds from the sale of investments 800                          
Investment Portfolio Benchmark | Customer Concentration Risk | Five Largest Portfolio Investments                            
Summary of Investment Holdings [Line Items]                            
Investments, at fair value 176,900                     $ 176,900 $ 174,500  
Concentration risk, percentage                       25.10% 26.90%  
Principal or Proprietary Transactions                            
Summary of Investment Holdings [Line Items]                            
Investments, at fair value $ 695,100                     $ 695,100 $ 630,800  
Principal or Proprietary Transactions | Investment Portfolio Benchmark | Investment Type Concentration Risk                            
Summary of Investment Holdings [Line Items]                            
Concentration risk, percentage                       98.60% 97.10%  
Uncalled capital commitment                            
Summary of Investment Holdings [Line Items]                            
Line of credit commitment                       $ 843 $ 843  
Uncalled capital commitment | HH-Inspire Acquisition, Inc.                            
Summary of Investment Holdings [Line Items]                            
Line of credit commitment         $ 1,800                  
Syndicated Investments                            
Summary of Investment Holdings [Line Items]                            
Number of proprietary investments | investment 4                     4 6  
Investments, at fair value $ 9,700                     $ 9,700 $ 18,800  
Syndicated Investments | Investment Portfolio Benchmark | Investment Type Concentration Risk                            
Summary of Investment Holdings [Line Items]                            
Concentration risk, percentage                       1.40% 2.90%  
[1] Cumulative gross unrealized depreciation for federal income tax purposes is $56.9 million; cumulative gross unrealized appreciation for federal income tax purposes is $33.7 million. Cumulative net unrealized depreciation is $23.2 million, based on a tax cost of $728.0 million.
[2] Cumulative gross unrealized depreciation for federal income tax purposes is $52.3 million; cumulative gross unrealized appreciation for federal income tax purposes is $35.2 million. Cumulative net unrealized depreciation is $17.1 million, based on a tax cost of $666.7 million.