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Maximum ownership percentage of outstanding common shares and preferred shares to exempt equity ownership limit.

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Maximum ownership percentage of outstanding common shares to exempt common share ownership limit.

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Payments for property management fees.

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Percentage of cash bonus.

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Related party transaction agreement date.

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Carrying value as of the balance sheet date of obligations incurred and payable for incentive compensation awarded to employees and directors or earned by them based on the terms of one or more relevant arrangements.

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Amount of expense for salary, wage, profit sharing; incentive and equity-based compensation; and other employee benefit.

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Amount of expense for salary and wage arising from service rendered by officer. Excludes allocated cost, labor-related nonsalary expense, and direct and overhead labor cost included in cost of good and service sold.

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Payments of cash to employees, including wages and salaries, during the current period.

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Amount of transactions with related party during the financial reporting period.

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Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Fees charged annually for the professional services of a trustee, usually quoted as a percentage of the funds being managed. The fee for appointing an offshore Trustee is included in the trust price.

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Related Party Transactions - Additional Information (Detail) - USD ($) $ in Thousands					1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	May 11, 2018	Apr. 06, 2018	Dec. 23, 2016	Dec. 20, 2016	Jan. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Mar. 30, 2018
Related Party Transaction [Line Items]
Reimbursed for general and administrative expense paid on IRT						$ 3,113	$ 3,529	$ 6,038	$ 7,016
Ballard Spahr LLP
Related Party Transaction [Line Items]
Trustee fee paid						$ 52		84
Ballard Spahr LLP \| Maximum
Related Party Transaction [Line Items]
Interest on trustee fee								$ 1
Libby Frischer Family Partnership
Related Party Transaction [Line Items]
Maximum common shares ownership percentage that would exempt common share ownership limit											12.50%
LFFP and Mr. Frischer \| Cooperation Agreement
Related Party Transaction [Line Items]
Related party transaction agreement date		Apr. 06, 2018
Maximum common shares and preferred shares ownership percentage that would exempt ownership limit		15.00%
LFFP and Mr. Frischer \| Letter Agreement
Related Party Transaction [Line Items]
Related party transaction agreement date	May 11, 2018
Maximum common shares and preferred shares ownership percentage that would exempt ownership limit	20.00%
Highland Capital Management, L. P.
Related Party Transaction [Line Items]
Related party transaction agreement date								May 26, 2017
IRT
Related Party Transaction [Line Items]
Reimbursed for general and administrative services									727
Reimbursed for general and administrative expense paid on IRT									155
Payments for property management fees									212
Earned and paid on consulting agreement									188
IRT \| Chief Executive Officer
Related Party Transaction [Line Items]
Compensation received				$ 375
Number of shares awarded, share			150,000
Cash payments					$ 500
IRT \| Chief Executive Officer \| Six Month Anniversary
Related Party Transaction [Line Items]
Vesting percentage			50.00%
IRT \| Chief Executive Officer \| One Year Anniversary
Related Party Transaction [Line Items]
Vesting percentage			50.00%
IRT \| James J. Sebra's
Related Party Transaction [Line Items]
Percentage of cash bonus										25.00%
Bonus							$ 110		$ 110