CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Total
Balance at Dec. 31, 2019	$ 1,067	$ 521,314	$ (516,780)	$ 5,601
Balance (in shares) at Dec. 31, 2019	106,734,279
Increase (Decrease) in Stockholders' Equity
Stock compensation accrued (Note 15)		52		52
Shares issued under the at-the-market offering agreement, net (Note 15)	$ 9	214		223
Shares issued under the at-the-market offering agreement, net (Note 15)(in shares)	823,452
Shares issued under the Lincoln Park commitment purchase agreement, net (Note 15)	$ 9	207		216
Shares issued under the Lincoln Park commitment purchase agreement, net (Note 15)(in shares)	900,000
Net loss			(3,336)	(3,336)
Balance at Mar. 31, 2020	$ 1,085	521,787	(520,116)	2,756
Balance (in shares) at Mar. 31, 2020	108,457,731
Balance at Dec. 31, 2020	$ 1,575	536,263	(525,866)	11,972
Balance (in shares) at Dec. 31, 2020	157,512,652
Increase (Decrease) in Stockholders' Equity
Stock compensation accrued (Note 15)		429		429
Shares issued under the at-the-market offering agreement, net (Note 15)	$ 19	1,681		1,700
Shares issued under the at-the-market offering agreement, net (Note 15)(in shares)	1,856,960
Warrants exercised (Note 15)	$ 31	984		1,015
Warrants exercised (Note 15) (in shares)	3,100,000
Net loss			(3,178)	(3,178)
Balance at Mar. 31, 2021	$ 1,625	$ 539,357	$ (529,044)	$ 11,938
Balance (in shares) at Mar. 31, 2021	162,469,612