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Related-Party Transactions - Additional Information (Detail) $ in Thousands |  |  | 12 Months Ended
--- | --- | --- | ---
Feb. 20, 2020 | Jan. 10, 2018 | Dec. 31, 2020 USD ($) officer | Dec. 31, 2019 USD ($)
Related Party Transaction [Line Items] |  |  |  |
Number of executive officers that serve as directors | officer |  |  | 2 |
Hurdle rate, quarterly (as percent) |  |  | 1.75% |
Hurdle rate, annual (as percent) |  |  | 7.00% |
Pre-incentive Fee FFO (as percent) |  |  | 100.00% |
Pre-Incentive Fee, exceeded (as percent) |  |  | 2.1875% |
Pre-Incentive Fee, exceeded, annual (as percent) |  |  | 8.75% |
Pre-Incentive Fee (as percent) |  |  | 20.00% |
Cumulative realized capital gains (as percent) |  |  | 15.00% |
Written notice (in days) |  |  | 120 days |
Financing fee |  |  | $ 262 | $ 235
Dealer-manager fees |  |  | $ 4,711 | 7,645
Prior Advisory Agreement |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Management fee (as percent) |  |  | 2.00% |
Base management fee, quarterly (as percent) |  |  | 0.50% |
2019 Advisory Agreement |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Management fee (as percent) |  |  | 2.00% |
Base management fee, quarterly (as percent) |  |  | 0.50% |
2020 Advisory Agreement |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Management fee (as percent) |  |  | 2.00% |
Base management fee, quarterly (as percent) |  |  | 0.50% |
Gladstone Securities |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Financing fee (as percent) |  |  | 0.14% |
Preferred Stock | Series B Preferred Stock |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Selling commission fee (as percent) |  | 7.00% |  |
Dealer-manager fee (as percent) |  | 3.00% |  |
Preferred Stock | Series B Preferred Stock | Gladstone Securities |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Dealer-manager fees |  |  | $ 2,500 | $ 7,600
Preferred Stock | Series C Preferred Stock |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Selling commission fee (as percent) | 6.00% |  |  |
Dealer-manager fee (as percent) | 3.00% |  |  |
Dealer-manager fees |  |  | $ 2,200 |
Gladstone Securities | Minimum | Gladstone Securities |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Financing fee (as percent) |  |  | 0.50% |
Gladstone Securities | Maximum | Gladstone Securities |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Financing fee (as percent) |  |  | 1.00% |

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- Definition Amount to be paid to adviser in percentage of pre incentive fee condition two. + References No definition available. + Details
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- Definition Dealer-Manager Fee Percent Of Gross Proceeds Limit + References No definition available. + Details
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- Definition Financing Fee + References No definition available. + Details
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- Definition Incentive fee per advisory agreement. + References No definition available. + Details
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- Definition Pre incentive fee in percentage of common stockholders equity that awards adviser hundred percent of amount of pre incentive fee maximum percentage. + References No definition available. + Details
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