Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Total
Beginning balance at Dec. 31, 2019	$ 2	$ 224,741	$ (219,160)	$ 5,583
Beginning Balance, (in shares) at Dec. 31, 2019	550,736
Share-based compensation expense		70		70
Fractional shares issued due to reverse stock split	7,692
Issuance of common stock and warrants in public offering		6,035		6,035
Issuance of common stock and warrants in public offering (in shares)	955,613
Issuance of common stock upon exercise of warrants		286		286
Issuance of common stock upon exercise of warrants (in shares)	1,057,512
Net loss			(2,414)	(2,414)
Ending balance at Mar. 31, 2020	$ 2	231,132	(221,574)	9,560
Ending Balance, (in shares) at Mar. 31, 2020	2,571,553
Beginning balance at Dec. 31, 2020	$ 3	247,417	(228,234)	$ 19,186
Beginning Balance, (in shares) at Dec. 31, 2020	23,631,886			23,631,886
Share-based compensation expense		52		$ 52
Issuance of common stock upon exercise of warrants		8,509		8,509
Issuance of common stock upon exercise of warrants (in shares)	10,632,870
Net loss			(2,223)	(2,223)
Ending balance at Mar. 31, 2021	$ 3	$ 255,978	$ (230,457)	$ 25,524
Ending Balance, (in shares) at Mar. 31, 2021	34,264,756			34,264,756