Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Restricted Stock Units (RSUs) [Member] Common Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2016		4,236,813
Balance at Dec. 31, 2016		$ 4	$ 80,720	$ (60,142)	$ 20,582
Exercise of stock options (in shares)		9,706
Exercise of stock options			144		144
Share-based compensation			2,707		2,707
Net loss				(12,308)	(12,308)
Issuance of restricted stock units in lieu of 2018 cash bonus
Balance (in shares) at Dec. 31, 2017		4,246,519
Balance at Dec. 31, 2017		$ 4	83,571	(72,450)	11,125
Exercise of stock options (in shares)		237
Exercise of stock options			4		4
Share-based compensation			2,774		2,774
Net loss				(13,987)	(13,987)
Adjustments to opening balance for change in accounting principle at Dec. 31, 2017				76	76
Issuance of stock and warrants, net of issuance costs (in shares)		592,597
Issuance of stock and warrants, net of issuance costs		$ 1	3,799		3,800
Restricted stock units vested and issued (in shares)	6,344
Issuance of restricted stock units in lieu of 2018 cash bonus
Balance (in shares) at Dec. 31, 2018		4,845,697
Balance at Dec. 31, 2018		$ 5	90,148	(86,361)	$ 3,792
Exercise of stock options (in shares)
Share-based compensation			2,722		$ 2,722
Net loss				(14,709)	(14,709)
Issuance of stock and warrants, net of issuance costs (in shares)		1,741,667
Issuance of stock and warrants, net of issuance costs		$ 2	9,194		9,196
Restricted stock units vested and issued (in shares)		27,426
Reverse stock split fractional share true up (in shares)		(494)
Issuance of stock and warrants from conversion of convertible notes (in shares)		210,887
Issuance of stock and warrants from conversion of convertible notes			1,204		1,204
Issuance of restricted stock units in lieu of 2018 cash bonus			165		165
Balance (in shares) at Dec. 31, 2019		6,825,183
Balance at Dec. 31, 2019		$ 7	$ 103,433	$ (101,070)	$ 2,370