Quarterly report pursuant to Section 13 or 15(d)

RELATED PARTY TRANSACTIONS - Narrative (Details)

v3.23.2
RELATED PARTY TRANSACTIONS - Narrative (Details) - USD ($)
 1 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended 24 Months Ended 36 Months Ended
Apr. 11, 2022
May 31, 2023
Jun. 30, 2023
Jun. 30, 2022
Jun. 30, 2023
Jun. 30, 2022
Mar. 31, 2023
Mar. 31, 2023
Apr. 11, 2022
Mar. 31, 2022
Mar. 31, 2023
Sep. 30, 2022
Related Party Transaction [Line Items]                        
Base management fee     1.75% 1.75% 1.75% 1.75%            
Base management fee, percent fee         100.00%              
Management and service fee, net of credit     0.50% 0.50% 0.50% 0.50%            
Management and service fees, loans         1.50%              
Ratio of net investment income (loss) to average net assets – annualized 2.1875%   8.77% 4.69% 8.32% 6.88%   2.50% 2.4375%      
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%   2.50%     2.4375%    
Pre-incentive fee net investment income exceeds the hurdle rate         20.00%              
Investment company, investment income (loss) ratio, before incentive allocation, annualized 8.75%             10.00% 9.75%      
Investment company, capital gains-based incentive fees     20.00%   20.00%              
Success fee income     $ 335,000 $ 0 $ 935,000 $ 4,794,000            
Investment company, other operating expenses, due to advisor     63,000   63,000             $ 44,000
Series A Preferred Stock | Dealer Manager Agreement                        
Related Party Transaction [Line Items]                        
Preferred stock, shares authorized (in shares)   6,000,000                    
Preferred stock, dividend rate, percentage   6.25%                    
Related Party                        
Related Party Transaction [Line Items]                        
Success fee income     500,000 $ 200,000 800,000 $ 800,000            
Fees due to related party     3,209,000   3,209,000             2,527,000
Related Party | Gladstone Investment Corporation                        
Related Party Transaction [Line Items]                        
Fees due to related party     $ 0   $ 0             $ 13,000
Adviser | Related Party | Chief Executive Officer                        
Related Party Transaction [Line Items]                        
Noncontrolling interest, ownership percentage by parent     100.00%   100.00%              
Administrator | Related Party | Chief Executive Officer                        
Related Party Transaction [Line Items]                        
Noncontrolling interest, ownership percentage by parent     100.00%   100.00%              
Gladstone Securities, LLC | Related Party | Chief Executive Officer                        
Related Party Transaction [Line Items]                        
Noncontrolling interest, ownership percentage by parent     100.00%   100.00%              
Maximum                        
Related Party Transaction [Line Items]                        
Base management fee         1.75%              
Minimum                        
Related Party Transaction [Line Items]                        
Ratio of net investment income (loss) to average net assets – annualized         1.75%           2.00%