Annual report [Section 13 and 15(d), not S-K Item 405]

RELATED-PARTY TRANSACTIONS - Narrative (Details)

v3.25.4
RELATED-PARTY TRANSACTIONS - Narrative (Details)
 12 Months Ended
Dec. 31, 2025
$ / shares
Dec. 31, 2024
$ / shares
Series E Preferred Stock    
Related Party Transaction [Line Items]    
Preferred stock, par value (in dollars per share) $ 0.001 $ 0.001
Gladstone Securities    
Related Party Transaction [Line Items]    
Notice period for termination of agreement without cause 120 days  
Termination agreement, percentage of independent directors 66.67%  
Multiplier 3  
Period prior to termination 24 months  
Advisory Agreement - Base Rate, Annualized Rate | Gladstone Securities    
Related Party Transaction [Line Items]    
Management and service fees, base rate 0.60%  
Advisory Agreement - Base Rate, Quarterly Rate | Gladstone Securities    
Related Party Transaction [Line Items]    
Management and service fees, base rate 0.15%  
Advisory Agreement - Incentive Rate, Quarterly Hurdle Rate | Gladstone Securities    
Related Party Transaction [Line Items]    
Management and service fees, incentive rate 1.75%  
Advisory Agreement - Incentive Rate, Annualized Hurdle Rate | Gladstone Securities    
Related Party Transaction [Line Items]    
Management and service fees, incentive rate 7.00%  
Advisory Agreement - Incentive Rate, Pre-Incentive Fee Net Investment Income Below Catch-Up Threshold | Gladstone Securities    
Related Party Transaction [Line Items]    
Management and service fees, incentive rate 100.00%  
Advisory Agreement - Incentive Rate, Quarterly Catch-Up Threshold | Gladstone Securities    
Related Party Transaction [Line Items]    
Management and service fees, incentive rate 2.1875%  
Advisory Agreement - Incentive Rate, Annualized Catch-Up Threshold | Gladstone Securities    
Related Party Transaction [Line Items]    
Management and service fees, incentive rate 8.75%  
Advisory Agreement - Incentive Rate, Pre-Incentive Fee Net Investment Income Exceeds Catch-Up Threshold | Gladstone Securities    
Related Party Transaction [Line Items]    
Management and service fees, incentive rate 20.00%  
Advisory Agreement - Incentive Rate, Realized Capital Gains | Gladstone Securities    
Related Party Transaction [Line Items]    
Management and service fees, incentive rate 15.00%  
Financing Arrangement Agreement, Percentage of Gross Proceeds | Gladstone Securities | Minimum    
Related Party Transaction [Line Items]    
Related party transaction, rate 0.50%  
Financing Arrangement Agreement, Percentage of Gross Proceeds | Gladstone Securities | Maximum    
Related Party Transaction [Line Items]    
Related party transaction, rate 1.00%  
Financing Arrangement Agreement, Percentage Of Financing Fees Paid    
Related Party Transaction [Line Items]    
Related party transaction, rate 0.14%  
Dealer-Manager Agreements | Series E Preferred Stock | Preferred Stock    
Related Party Transaction [Line Items]    
Dividend rate 5.00%  
Preferred stock, par value (in dollars per share) $ 0.001  
Dealer-Manager Agreements, Selling Commissions of Gross Proceeds from Sales | Series E Preferred Stock | Preferred Stock    
Related Party Transaction [Line Items]    
Related party transaction, rate 7.00%  
Dealer-Manager Agreements, Dealer-Manager Fee of Gross Proceeds from Sales | Series E Preferred Stock | Preferred Stock    
Related Party Transaction [Line Items]    
Related party transaction, rate 3.00%