Schedule III - Real Estate and Accumulated Depreciation (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Accumulated Depreciation		$ (23,584)	$ (30,627)	$ (56,448)	$ (51,553)
Net Liquidation Adjustment		(12,580)
Total		377,446	$ 587,952	$ 670,868	$ 421,989
Office [Member] | Orlando [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		35,668
Initial Cost to Company, Building and Improvements		17,248
Building and Improvements		17,290
Accumulated Depreciation	[1]	(4,196)
Total		$ 13,094
Date Acquired		2004-11
Life		40 years
Office [Member] | Plantation [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 10,406
Initial Cost to Company, Building and Improvements		8,915
Land		4,000
Building and Improvements		8,935
Accumulated Depreciation	[1]	(2,169)
Total		$ 10,766
Date Acquired		2004-11
Life		40 years
Office [Member] | Chicago 1 [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 19,104
Initial Cost to Company, Building and Improvements		23,635
Building and Improvements		28,326
Accumulated Depreciation	[1]	(6,280)
Total		$ 22,046
Date Acquired		2005-10
Life		40 years
Office [Member] | Lisle 1 [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 5,459
Initial Cost to Company, Land		3,774
Initial Cost to Company, Building and Improvements		16,371
Land		3,774
Building and Improvements		8,576
Accumulated Depreciation	[1]	(806)
Total		$ 11,544
Date Acquired		2006-02
Life		40 years
Office [Member] | Lisle 2 [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 5,309
Initial Cost to Company, Land		780
Initial Cost to Company, Building and Improvements		2,803
Land		780
Building and Improvements		3,492
Accumulated Depreciation	[1]	(690)
Total		$ 3,582
Date Acquired		2006-02
Life		40 years
Other [Member] | Jacksonville [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Initial Cost to Company, Land		$ 2,166
Initial Cost to Company, Building and Improvements		8,684
Land		2,166
Building and Improvements		10,305
Accumulated Depreciation	[1]	(715)
Total		$ 11,756
Date Acquired		2004-11
Life		40 years
Other [Member] | Churchill [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 4,782
Initial Cost to Company, Building and Improvements		23,834
Building and Improvements		9,705
Accumulated Depreciation	[1]	(4,301)
Total		$ 5,404
Date Acquired		2004-11
Life		40 years
Other [Member] | Greensboro [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 13,600
Initial Cost to Company, Land		1,961
Initial Cost to Company, Building and Improvements		16,482
Land		1,952
Building and Improvements		16,643
Accumulated Depreciation	[1]	(1,152)
Total		$ 17,443
Date Acquired		2012-11
Life		40 years
Other [Member] | Stamford [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 33,448
Initial Cost to Company, Land		5,707
Initial Cost to Company, Building and Improvements		73,460
Land		5,707
Building and Improvements		73,557
Accumulated Depreciation	[1]	(1,414)
Total		$ 77,850
Date Acquired		2013-10
Life		40 years
Other [Member] | Houston [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		$ 44,319
Initial Cost to Company, Land		16,167
Initial Cost to Company, Building and Improvements		88,769
Land		16,167
Building and Improvements		89,844
Accumulated Depreciation	[1]	(1,861)
Total		$ 104,150
Date Acquired		2013-10
Life		40 years
Net Liquidation Adjustment [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Net Liquidation Adjustment	[2]	$ 76,227
Total	[2]	76,227
Liquidation Value [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Encumbrances		172,095
Initial Cost to Company, Land		30,555
Initial Cost to Company, Building and Improvements		280,201
Land		34,546
Building and Improvements		266,673
Accumulated Depreciation	[1]	(23,584)
Net Liquidation Adjustment	[2]	76,227
Total		$ 353,862

[1] Depreciation expense will not be recorded subsequent to July 31, 2014 as a result of the adoption of the plan of liquidation.

[2] Under the liquidation basis of accounting, real estate holdings are now carried at their estimated net realizable values. As a result, the net liquidation adjustment is the net adjustment that the Trust has made to the carrying value of the properties in order to reflect their liquidation values.