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Related-Party Transactions (Details) |  |  |  | 3 Months Ended | 9 Months Ended |
--- | --- | --- | --- | --- | --- | ---
Jul. 11, 2023 | Jul. 14, 2020 | Feb. 20, 2020 $ / shares shares | Sep. 30, 2024 USD ($) | Sep. 30, 2023 USD ($) | Sep. 30, 2024 USD ($) officer quarter | Sep. 30, 2023 USD ($) | Dec. 31, 2023 USD ($)
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Number of executive officers | officer |  |  |  |  |  |  | 2 |  |
Related Party |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Amount due to advisor and administrator | [1] |  |  |  | $ 3,063,000 |  | $ 3,063,000 |  | $ 2,556,000
Advisory Agreement |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Number of quarters used for the cap of average quarterly incentive fees | quarter |  |  |  |  |  |  | 4 |  |
Advisory Agreement | Affiliated Entity |  |  |  |  |  |  |  |  |
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 |  |
Advisory Agreement - Base Rate, Annualized Rate | Affiliated Entity |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Management and service fees, base rate |  |  | 0.425% |  |  |  |  |  |
Advisory Agreement - Base Rate, Quarterly Rate | Affiliated Entity |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Management and service fees, base rate |  |  | 0.10625% |  |  |  |  |  |
Advisory Agreement - Base Management Fee |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Related party transaction, amounts of transaction |  |  |  |  | $ 1,500,000 | $ 1,600,000 | $ 4,600,000 | $ 4,800,000 |
Advisory Agreement - Incentive Rate, Quarterly Hurdle Rate | Affiliated Entity |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Management and service fees, incentive rate |  |  |  |  |  |  | 2.00% |  |
Advisory Agreement - Incentive Rate, Annualized Hurdle Rate | Affiliated Entity |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Management and service fees, incentive rate |  |  |  |  |  |  | 8.00% |  |
Advisory Agreement - Incentive Rate, Pre-Incentive Fee Net Investment Income Below Catch-Up Threshold | Affiliated Entity |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Management and service fees, incentive rate |  |  |  |  |  |  | 15.00% |  |
Advisory Agreement - Incentive Rate, Pre-Incentive Fee Net Investment Income Exceeds Catch-Up Threshold | Affiliated Entity |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Management and service fees, incentive rate |  |  |  |  |  |  | 15.00% |  |
Eight Amended Advisory Agreement | Affiliated Entity |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Management and service fees, incentive rate |  | 15.00% |  |  |  |  |  |  |
Advisory Agreement - Incentive Fees | Affiliated Entity |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Related party transaction, amounts of transaction |  |  |  |  | 1,100,000 |  | $ 3,600,000 |  |
Investment company, voluntary fee waived |  |  |  |  | 400,000 |  | 1,400,000 |  |
Contractual fee waived |  |  |  |  |  | 900,000 |  | 3,400,000 |
Advisory Agreement - Incentive Rate, Realized Capital Gains |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Related party transaction, amounts of transaction |  |  |  |  | 0 | 0 | $ 0 | 0 |
Advisory Agreement - Incentive Rate, Realized Capital Gains | Affiliated Entity |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Management and service fees, incentive rate |  |  |  |  |  |  | 15.00% |  |
Advisory Agreement - Termination Fee Payable as a Percentage of Management and Incentive Fees Earned by Adviser | Affiliated Entity |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Related party transaction, rate |  |  |  |  |  |  | 200.00% |  |
Administrative Agreement - Administrative Fee |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Related party transaction, amounts of transaction |  |  |  |  | 700,000 | 600,000 | $ 2,000,000.0 | 1,700,000 |
Mortgage Financing Arrangement Agreement - Financing Fees | Gladstone Securities, LLC |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Related party transaction, amounts of transaction |  |  |  |  | $ 0 | $ 30,000.00 | $ 10,000.00 | $ 100,000 |
Mortgage Financing Arrangement Agreement - Percentage of Mortgage Principal Secured | Gladstone Securities, LLC |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Related party transaction, rate |  |  |  |  | 0.13% | 0.38% | 0.13% | 0.29% |
Dealer Manager Agreement | Gladstone Securities, LLC |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Related party transaction, amounts of transaction |  |  |  |  | $ 10,000.00 | $ 100,000 | $ 70,000.00 | $ 500,000 |
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% |  |  |  |  |
Series F Cumulative Redeemable Preferred Stock | Preferred Stock | Dealer Manager Agreement | Affiliated Entity | Gladstone Securities, LLC |  |  |  |  |  |  |  |  |
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 |  |  |  |  |
Minimum | Mortgage Financing Arrangement Agreement - Financing Fees | Gladstone Securities, LLC |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Related party transaction, rate |  |  |  |  |  |  | 0.15% |  |
Maximum | Mortgage Financing Arrangement Agreement - Financing Fees | Gladstone Securities, LLC |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |
Related party transaction, rate |  |  |  |  |  |  | 1.00% |  |
[1] | Refer to Note 2 “Related-Party Transactions”

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