Unaudited Quarterly Operating Results (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	Dec. 31, 2013
Selected Quarterly Financial Information [Abstract]
Total Revenue	$ 15,884	$ 12,187	$ 7,159	$ 16,826	$ 14,949	$ 14,056	$ 8,526	$ 14,760	$ 52,056	$ 52,291
Net Income (Loss) attributable to Common Stockholders	$ 1,715	$ (788)	$ 406	$ 1,617	$ 1,916	$ 1,752	$ 874	$ 1,113	$ 2,950	$ 5,655	$ 4,165
Net Income(Loss), Per Share attributable to Common Stockholders (in dollars per share)	$ 0.08	$ (0.04)	$ 0.02	$ 0.08	$ 0.09	$ 0.09	$ 0.04	$ 0.05	$ 0.14	$ 0.27	$ 0.20
Reportable Segment
Selected Quarterly Financial Information [Abstract]
Segment Profit (Loss)	$ 4,221	$ (614)	$ 1,362	$ 4,643	$ 3,129	$ 3,304	$ 2,154	$ 4,002	$ 9,612	$ 12,589