Related-Party Transactions - Additional Information (Detail) - USD ($)		1 Months Ended	12 Months Ended
	May 02, 2018	May 31, 2018	Dec. 31, 2018	Dec. 31, 2014	Dec. 31, 2017
Related Party Transaction [Line Items]
Management fees			$ 0
FUR Advisors [Member]
Related Party Transaction [Line Items]
Percentage of equity contributions			1.50%
Percentage of equity contributions by unaffiliated third parties			0.25%
Reduction in liquidating distribution amount paid on equity		$ 0
Percentage of amount available for distribution in excess of threshold amount			20.00%
Threshold amount				$ 569,963,000
Percentage of growth rate on incentive fee				4.00%
Yield plus percentage				2.50%
Threshold amount required to be distributed before incentive fee			$ 17,391,000
Per share Threshold amount required to be distributed			$ 0.49
Reduced threshold amount			$ 104,980,000
Percentage of dividends paid on disposition			20.00%
Termination fees	$ 9,496,000
Supplemental fee payment terms, description			Payable equal to the lesser of (i) the base management fee paid to our Advisor for the twelve month period immediately prior to the approved plan of liquidation or (ii) 20% of any liquidating distributions paid on account of our Units at such time as the threshold amount was reduced to $104,980,000. No additional termination fee payments will be paid.
Payable to related parties included in related party fees payable			$ 0		$ 751,000
FUR Advisors [Member] | US Treasury Bill Securities [Member]
Related Party Transaction [Line Items]
Period for growth factor on incentive				5 years
Winthrop Management LP [Member]
Related Party Transaction [Line Items]
Payable to related parties included in related party fees payable			$ 3,000		$ 17,000