CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning Balance at Dec. 31, 2016	$ 8,240	$ 0	$ 40,374	$ (32,134)
Beginning Balance (in shares) at Dec. 31, 2016		478
Issuance of common stock, net of fees	3,567	$ 1	3,566
Issuance of common stock, net of fees (in shares)		67
Exercise of warrants	1,518	$ 0	1,518
Exercise of warrants (in shares)		22
Warrants transferred to equity upon modification	797		797
Conversion of warrant liability to equity	175		175
Stock-based compensation	793		793
Deemed dividend related to warrant modification	(1,038)		(1,038)
Modification of warrant exercise price	1,038		1,038
Net loss	(7,023)			(7,023)
Ending Balance at Dec. 31, 2017	8,067	$ 1	47,223	(39,157)
Ending Balance (in shares) at Dec. 31, 2017		567
Issuance of common stock, net of fees	1,180	$ 0	1,180
Issuance of common stock, net of fees (in shares)		113
Stock-based compensation	554		554
Net loss	(8,583)			(8,583)
Ending Balance at Dec. 31, 2018	$ 1,218	$ 1	$ 48,957	$ (47,740)
Ending Balance (in shares) at Dec. 31, 2018		680