Unaudited Quarterly Operating Results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information [Line Items]
Total Revenue	$ 20,525	$ 9,951	$ 9,275	$ 11,011	$ 12,012	$ 15,783	$ 5,416	$ 13,752	$ 50,762	$ 46,963
Net Income (Loss)	9,709	37	709	124	306	3,487	(1,013)	1,455	10,579	4,235	$ (1,821)
Net Income (Loss) attributable to Common Stockholders	$ 9,707	$ 47	$ 707	$ 119	$ 307	$ 3,488	$ (997)	$ 1,457	$ 10,580	$ 4,255	$ (1,797)
Net (Loss) Income Per Share (in dollars per share)	$ 0.37	$ 0.00	$ 0.03	$ 0.00	$ 0.01	$ 0.13	$ (0.04)	$ 0.06	$ 0.41	$ 0.16	$ (0.08)
Net (Loss) Income, Per Share attributable to Common Stockholders (in dollars per share)	$ 0.37	$ 0.00	$ 0.03	$ 0.00	$ 0.01	$ 0.13	$ (0.04)	$ 0.06	$ 0.40	$ 0.16	$ (0.08)
Reportable Segment
Quarterly Financial Information [Line Items]
Segment Profit (Loss)	$ 6,301	$ (708)	$ 895	$ 1,442	$ 934	$ 4,815	$ 115	$ 4,277	$ 7,930	$ 10,141