Quarterly Financial Information (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015		Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Total revenue	$ 11,328	$ 11,152	$ 10,555	$ 11,079	$ 10,897	$ 11,438	$ 10,870	$ 10,915	$ 44,114		$ 44,120
Net income (loss)	(3,830)	(3,076)	(4,029)	(3,329)	(4,094)	(4,435)	(5,128)	(3,695)	(14,264)		(17,352)
Net income (loss) attributable to common stockholders	$ (1,056)	$ (891)	$ (1,100)	$ (947)	$ (1,114)	$ (1,188)	$ (1,340)	$ (1,027)	$ (3,994)	[1]	$ (4,669)	[1]
Net income (loss) per common share - basic and diluted (in usd per share)	$ (0.26)	$ (0.23)	$ (0.28)	$ (0.24)	$ (0.28)	$ (0.30)	$ (0.34)	$ (0.26)	$ (1.01)		$ (1.18)
Weighted average number of shares outstanding - basic and diluted (in shares)	3,941,242	3,941,242	3,941,242	3,941,242	3,941,242	3,941,242	3,941,242	3,941,242	3,941,242		3,941,242

[1] For each of the years ended December 31, 2015 and 2014, net loss attributable to common stockholders includes $2.3 million of priority allocation to Preferred Unit holders, which is included in non-controlling interests in the consolidated statements of operations. The Company continues to accrue the distributions but does not anticipate paying the distributions in the near term. See below for additional detail.