Quarterly report [Sections 13 or 15(d)]

Related Party Transactions (Details)

v3.25.3
Related Party Transactions (Details)
 3 Months Ended 9 Months Ended
Jul. 11, 2023
Feb. 20, 2020
$ / shares
shares
Sep. 30, 2025
USD ($)
Sep. 30, 2024
USD ($)
Sep. 30, 2025
USD ($)
officer
quarter
Sep. 30, 2024
USD ($)
Dec. 31, 2024
USD ($)
Related Party Transaction [Line Items]              
Number of executive officers | officer         1    
Advisory Agreement              
Related Party Transaction [Line Items]              
Number of quarters used for the cap of average quarterly incentive fees | quarter         4    
Advisory Agreement - Base Management Fee              
Related Party Transaction [Line Items]              
Related party transaction, amounts of transaction     $ 1,700,000 $ 1,500,000 $ 4,900,000 $ 4,600,000  
Advisory Agreement - Incentive Rate, Realized Capital Gains              
Related Party Transaction [Line Items]              
Related party transaction, amounts of transaction     0 0 0 0  
Administrative Agreement - Administrative Fee              
Related Party Transaction [Line Items]              
Related party transaction, amounts of transaction     700,000 700,000 1,900,000 2,000,000.0  
Mortgage Financing Arrangement Agreement - Financing Fees | Gladstone Securities, LLC              
Related Party Transaction [Line Items]              
Related party transaction, amounts of transaction     0 $ 0 $ 0 $ 9,233  
Mortgage Financing Arrangement Agreement - Financing Fees | Minimum | Gladstone Securities, LLC              
Related Party Transaction [Line Items]              
Related party transaction, rate         0.15%    
Mortgage Financing Arrangement Agreement - Financing Fees | Maximum | Gladstone Securities, LLC              
Related Party Transaction [Line Items]              
Related party transaction, rate         1.00%    
Mortgage Financing Arrangement Agreement - Percentage of Mortgage Principal Secured | Gladstone Securities, LLC              
Related Party Transaction [Line Items]              
Related party transaction, rate       0.13%   0.13%  
Dealer Manager Agreement | Gladstone Securities, LLC              
Related Party Transaction [Line Items]              
Related party transaction, amounts of transaction     0 $ 10,000.00 $ 30,000.00 $ 70,000.00  
Dealer Manager Agreement - Selling Commission Percentage of Gross Proceeds from Sales              
Related Party Transaction [Line Items]              
Related party transaction, rate   6.00%          
Dealer Manager Agreement - Dealer Management Fee Percentage of Gross Proceeds from Sale of Preferred Stock in Primary Offering              
Related Party Transaction [Line Items]              
Related party transaction, rate   3.00%          
Related Party              
Related Party Transaction [Line Items]              
Amount due to advisor and administrator [1]     $ 2,468,000   $ 2,468,000   $ 2,540,000
Affiliated Entity | Advisory Agreement              
Related Party Transaction [Line Items]              
Notice period for termination of agreement without cause         120 days    
Percentage of independent directors required to terminate the amended advisory agreement         66.67%    
Number of times the sum of the average annual base management fee and incentive fee earned by adviser     2   2    
Period prior to termination         24 months    
Notice period for termination of agreement with cause         30 days    
Affiliated Entity | Advisory Agreement - Base Rate, Annualized Rate              
Related Party Transaction [Line Items]              
Management and service fees, base rate         0.425%    
Affiliated Entity | Advisory Agreement - Base Rate, Quarterly Rate              
Related Party Transaction [Line Items]              
Management and service fees, base rate         0.10625%    
Affiliated Entity | Advisory Agreement - Incentive Rate, Quarterly Hurdle Rate              
Related Party Transaction [Line Items]              
Management and service fees, incentive rate         2.00%    
Affiliated Entity | Advisory Agreement - Incentive Rate, Annualized Hurdle Rate              
Related Party Transaction [Line Items]              
Management and service fees, incentive rate         8.00%    
Affiliated Entity | Advisory Agreement - Incentive Rate, Pre-Incentive Fee Net Investment Income Below Catch-Up Threshold              
Related Party Transaction [Line Items]              
Management and service fees, incentive rate         15.00%    
Affiliated Entity | Advisory Agreement - Incentive Rate, Pre-Incentive Fee Net Investment Income Exceeds Catch-Up Threshold              
Related Party Transaction [Line Items]              
Management and service fees, incentive rate         15.00%    
Affiliated Entity | Eight Amended Advisory Agreement              
Related Party Transaction [Line Items]              
Management and service fees, incentive rate 15.00%            
Affiliated Entity | Advisory Agreement - Incentive Fees              
Related Party Transaction [Line Items]              
Related party transaction, amounts of transaction     $ 700,000 1,100,000 $ 2,100,000 3,600,000  
Investment company, voluntary fee waived     $ 700,000 $ 400,000 $ 1,400,000 $ 1,400,000  
Affiliated Entity | Advisory Agreement - Incentive Rate, Realized Capital Gains              
Related Party Transaction [Line Items]              
Management and service fees, incentive rate         15.00%    
Affiliated Entity | Advisory Agreement - Termination Fee Payable as a Percentage of Management and Incentive Fees Earned by Adviser              
Related Party Transaction [Line Items]              
Related party transaction, rate         200.00%    
Affiliated Entity | Dealer Manager Agreement | Gladstone Securities, LLC | Series F Cumulative Redeemable Preferred Stock | Preferred Stock              
Related Party Transaction [Line Items]              
Redeemable preferred stock, shares authorized (in shares) | shares   20,000,000          
Redeemable preferred stock, dividend rate   6.00%          
Redeemable preferred stock, par value (in dollars per share) | $ / shares   $ 0.001          
Redeemable preferred stock, dividend reinvestment plan, shares authorized (in shares) | shares   6,000,000          
[1] Refer to Note 2 “Related Party Transactions”