Quarterly report [Sections 13 or 15(d)]

Summary of Significant Accounting Policies - Concentrations of Portfolio Company Values Compared to the Fair Value of the Corporation's Total Investment Portfolio (Details)

v3.25.3
Summary of Significant Accounting Policies - Concentrations of Portfolio Company Values Compared to the Fair Value of the Corporation's Total Investment Portfolio (Details)
9 Months Ended 12 Months Ended
Sep. 30, 2025
Dec. 31, 2024
Tilson    
Concentration Risk [Line Items]    
Concentration risk investment portfolio   16.00%
Seybert's    
Concentration Risk [Line Items]    
Concentration risk investment portfolio   11.00%
FSS    
Concentration Risk [Line Items]    
Concentration risk investment portfolio 10.00% 10.00%
All About People    
Concentration Risk [Line Items]    
Concentration risk investment portfolio 9.00%  
EFINEA    
Concentration Risk [Line Items]    
Concentration risk investment portfolio 11.00%  
Mattison    
Concentration Risk [Line Items]    
Concentration risk investment portfolio   8.00%
First Coast Mulch    
Concentration Risk [Line Items]    
Concentration risk investment portfolio 9.00%  
Caitec    
Concentration Risk [Line Items]    
Concentration risk investment portfolio 11.00% 6.00%