Quarterly report pursuant to Section 13 or 15(d)

RELATED PARTY TRANSACTIONS - Narrative (Details)

v3.23.2
RELATED PARTY TRANSACTIONS - Narrative (Details) - USD ($)
3 Months Ended 12 Months Ended
Jun. 30, 2023
Jun. 30, 2022
Mar. 31, 2023
Related Party Transaction [Line Items]      
Base management fee 2.00% 2.00%  
Investment company, excess expense reimbursable $ 75,000 $ 36,000  
Ratio of net investment income (loss) to average net assets – annualized 4.55% 4.37%  
Investment company, capital gains-based incentive fees $ 0   $ 0
Investment company, capital gains-based incentive fees payable (reversal) 100,000 $ 900,000  
Administration fee [1] 522,000 380,000  
Success fee income 0 5,000,000  
Related Party      
Related Party Transaction [Line Items]      
Success fee income 300,000 $ 300,000  
Due from related parties $ 0   $ 0
Related Party | Adviser | Chief Executive Officer      
Related Party Transaction [Line Items]      
Noncontrolling interest, ownership percentage by parent 100.00%    
Related Party | Administrator | Chief Executive Officer      
Related Party Transaction [Line Items]      
Noncontrolling interest, ownership percentage by parent 100.00%    
Related Party | Gladstone Securities, LLC | Chief Executive Officer      
Related Party Transaction [Line Items]      
Noncontrolling interest, ownership percentage by parent 100.00%    
Advisory Agreement | Affiliated Entity      
Related Party Transaction [Line Items]      
Base management fee 2.00%    
Base management fee, percent fee 100.00%    
Maximum base management fee paid cannot exceed a percentage of total assets 2.00%    
Incentive fee base on minimum rate of return required on investment $ 0    
Percentage of pre-incentive fee net investment income is less than the hurdle rate 100.00%    
Investment company, pre-incentive fee net investment income, percent threshold of net assets 2.1875%    
Pre-incentive fee net investment income exceeds the hurdle rate 20.00%    
Investment company, capital gains-based incentive fees 20.00%    
Advisory Agreement | Affiliated Entity | Minimum      
Related Party Transaction [Line Items]      
Ratio of net investment income (loss) to average net assets – annualized 1.75%    
[1] Refer to Note 4 — Related Party Transactions in the accompanying Notes to Consolidated Financial Statements for additional information.