Real Estate and Accumulated Depreciation Schedule III - Summary of Activity for Real Estate and Accumulated Depreciation (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Real Estate:
Balance at beginning of year			$ 209,972	$ 265,879	$ 329,643
Acquisitions			36,189	0	0
Improvements	[1]		1,279	2,190	2,044
Disposals/written-off			(168)	0	(77)
Reclassification	[2]		(16)	(105)	(390)
Establishment of new basis for impaired asset	[3]		(6,347)	0	(4,149)
Cost of real estate sold			(43,481)	(57,992)	(61,192)
Balance at end of year		$ 197,428	197,428	209,972	265,879
Accumulated depreciation:
Balance at beginning of year			34,903	29,108	27,569
Depreciation expense			12,209	8,759	11,109
Disposals/written-off			(11,219)	(2,964)	(6,838)
Accumulated depreciation on impaired asset	[3]		(2,215)	0	(2,732)
Balance at end of year		33,678	33,678	34,903	29,108
Impairment charge		$ 4,100	$ 4,132	0	1,417
Foreign currency translation loss					1,600
Reclassification from improvements to furniture, fixtures and equipment				$ 100	$ 400

[1] For the year ended December 31, 2015, includes foreign currency translation loss of $1.6 million.

[2] For the years ended December 31, 2016 and 2015, includes reclassification from improvements to furniture, fixtures, and equipment of $0.1 million and $0.4 million, respectively.

[3] We recorded non-cash impairment charges of $4.1 million and $1.4 million on our investment in 22 Exchange, a student housing property, during the years ended December 31, 2017 and December 31, 2015, respectively. The accumulated depreciation at the time of the impairment charge for this asset, of $2.2 million and $2.7 million, respectively, was offset against the basis of the asset.