Quarterly Financial Data (Unaudited) - Schedule of Quarterly Financial Data (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]                    
Revenue $ 7,121 $ 7,223 $ 6,903 $ 6,767 $ 6,791 $ 6,612 $ 6,345 $ 5,408 $ 28,014 $ 25,156
Loss from operations (3,293) (2,941) (3,406) (6,336) (8,193) (7,543) (7,702) (8,071) (15,976) (31,509)
Net loss $ (4,340) $ (3,982) $ (4,344) $ (7,254) $ (8,925) $ (8,064) $ (8,072) $ (8,168) $ (19,920) $ (33,229)
Weighted average number of shares outstanding, basic 5,360,000 5,335,000 4,485,000 3,383,000 3,376,000 3,373,000 3,366,000 3,364,000 4,647,983 [1] 3,369,808 [1]
Net loss per common share basic $ (0.81) $ (0.75) $ (0.97) $ (2.14) $ (2.64) $ (2.39) $ (2.40) $ (2.43) $ (4.29) [1] $ (9.86) [1]
Weighted average number of shares outstanding diluted 5,360,000 5,335,000 4,485,000 3,383,000 3,376,000 3,377,000 3,370,000 3,369,000 4,647,983 [1] 3,373,180 [1]
Net loss per common share diluted $ (0.81) $ (0.75) $ (0.97) $ (2.14) $ (2.64) $ (2.39) $ (2.39) $ (2.42) $ (4.29) [1] $ (9.92) [1]
[1] Restated for a 1-for-10 reverse stock split effected February 27, 2017.