Equity Investments - Trust's Nominal Ownership Percentages in its Equity Investments (Parenthetical) (Detail)	Mar. 31, 2016
701 Seventh WRT Investor LLC [Member] \| New Valley/Witkoff [Member]
Schedule of Equity Method Investments [Line Items]
Effective ownership interest of trust in underlying property	61.14%

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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