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Related-Party Transactions - Additional Information (Detail) |  | 3 Months Ended | 6 Months Ended |
--- | --- | --- | --- | ---
Jan. 10, 2017 quarter | Jun. 30, 2018 USD ($) | Jun. 30, 2017 USD ($) | Jun. 30, 2018 USD ($) officer | Jun. 30, 2017 USD ($) | Dec. 31, 2017 USD ($)
Related Party Transaction [Line Items] |  |  |  |  |  |  |
Number of executive officers | officer |  |  |  |  | 2 |  |
Amount due to Adviser and Administrator | [1] |  | $ 2,352,000 |  | $ 2,352,000 |  | $ 2,289,000
Annual base management fee, in percentage of stockholders' equity, adjusted to unrealized gains or losses (as percent) |  | 1.50% |  |  |  |  |
Quarterly base management fee, in percentage of stockholders' equity, adjusted to unrealized gains or losses (as percent) |  | 0.375% |  |  |  |  |
Base management fee | [2] |  | 1,260,000 | $ 1,207,000 | 2,556,000 | $ 2,387,000 |
Pre-incentive quarterly fee FFO in percentage of common stockholders' equity that will reward the Adviser (as percent) |  | 2.00% |  |  |  |  |
Pre-incentive annual fee FFO in percentage of common stockholders' equity that will reward the Adviser (as percent) |  | 8.00% |  |  |  |  |
Amount to be paid to Adviser in percentage of pre-incentive fee condition one (as percent) |  | 15.00% |  |  |  |  |
Number of quarters used for the cap of average quarterly incentive fees | quarter |  | 4 |  |  |  |  |
Incentive fee | [2] |  | 733,000 | 551,000 | 1,429,000 | 1,120,000 |
Portion of incentive fee waived |  |  | 0 | 0 | 0 | 0 |
Capital gains-based incentive fee (as percent) |  | 15.00% |  |  |  |  |
Capital gain fee |  |  | 0 | 0 | 0 | 0 |
Notice period for termination of agreement without cause |  | 120 days |  |  |  |  |
Percentage of independent directors to terminate the Amended Advisory Agreement (as percent) |  | 66.67% |  |  |  |  |
Termination fee payable (as percent) |  | 200.00% |  |  |  |  |
Notice period for termination of agreement with cause |  | 30 days |  |  |  |  |
Administration fee | [2] |  | 360,000 | 340,000 | 747,000 | 700,000 |
Fees paid |  |  | $ 1,000 | $ 60,000 | $ 20,000 | $ 60,000 |
Financing fee on total secured mortgages percentage (as percent) |  |  | 0.01% | 0.31% | 0.11% | 31.00% |
Minimum |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |
Percentage of the amount of the mortgage (as percent) |  |  |  |  | 0.15% |  |
Maximum |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |
Percentage of the amount of the mortgage (as percent) |  |  |  |  | 1.00% |  |
[1] | Refer to Note 2 “Related-Party Transactions”
[2] | Refer to Note 2 “Related-Party Transactions”

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