Net Loss per Share - Computation of diluted net loss per weighted average number of shares outstanding (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Net Loss per Share
Net loss - Basic	$ (5,253)	$ (3,741)	$ (12,934)	$ (10,375)
Dilutive shares related to warrants	0	0	0	0
Net loss - Dilutive	$ (5,253)	$ (3,741)	$ (12,934)	$ (10,375)
Weighted Average Number of Shares Outstanding, Basic	16,805,257	4,028,304	16,313,326	3,802,812
Dilutive shares related to warrants	0	0	0	0
Weighted Average Number of Shares Outstanding, Diluted	16,805,257	4,028,304	16,313,326	3,802,812
Earnings Per Share, Basic, Total	$ (0.31)	$ (0.93)	$ (0.79)	$ (2.73)
Earnings Per Share, Diluted, Total	$ (0.31)	$ (0.93)	$ (0.79)	$ (2.73)