Related-Party Transactions - Fees and Reimbursements Paid or Accrued by Winthrop and Liquidating Trust (Detail) - Winthrop Management [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Fees and reimbursements paid by the Trust	$ 3,817	$ 5,211
Base Asset Management Fee [Member]
Related Party Transaction [Line Items]
Fees and reimbursements paid by the Trust	3,258	4,575
Property Management Fee [Member]
Related Party Transaction [Line Items]
Fees and reimbursements paid by the Trust	532	633
Construction Management Fee [Member]
Related Party Transaction [Line Items]
Fees and reimbursements paid by the Trust	$ 27	$ 3