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		115		115
Issuance of common stock upon vesting of restricted stock units (in shares)	50
Fractional shares issued due to reverse stock split	7,692
Issuance of common stock and warrants in public offering		8,592		8,592
Issuance of common stock and warrants in public offering (in shares)	2,670,853
Issuance of common stock upon exercise of warrants		343		343
Issuance of common stock upon exercise of warrants (in shares)	1,653,089
Net loss			(4,603)	(4,603)
Ending balance at Jun. 30, 2020	$ 2	233,791	(223,763)	10,030
Ending Balance, (in shares) at Jun. 30, 2020	4,882,420
Beginning balance at Mar. 31, 2020	$ 2	231,132	(221,574)	9,560
Beginning Balance, (in shares) at Mar. 31, 2020	2,571,553
Share-based compensation expense		45		45
Issuance of common stock upon vesting of restricted stock units (in shares)	50
Issuance of common stock and warrants in public offering		2,557		2,557
Issuance of common stock and warrants in public offering (in shares)	1,715,240
Issuance of common stock upon exercise of warrants		57		57
Issuance of common stock upon exercise of warrants (in shares)	595,577
Net loss			(2,189)	(2,189)
Ending balance at Jun. 30, 2020	$ 2	233,791	(223,763)	10,030
Ending Balance, (in shares) at Jun. 30, 2020	4,882,420
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		147		$ 147
Issuance of common stock upon vesting of restricted stock units (in shares)	50
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			(4,532)	(4,532)
Ending balance at Jun. 30, 2021	$ 3	256,073	(232,766)	$ 23,310
Ending Balance, (in shares) at Jun. 30, 2021	34,264,806			34,264,806
Beginning balance at Mar. 31, 2021	$ 3	255,978	(230,457)	$ 25,524
Beginning Balance, (in shares) at Mar. 31, 2021	34,264,756
Share-based compensation expense		95		95
Issuance of common stock upon vesting of restricted stock units (in shares)	50
Net loss			(2,309)	(2,309)
Ending balance at Jun. 30, 2021	$ 3	$ 256,073	$ (232,766)	$ 23,310
Ending Balance, (in shares) at Jun. 30, 2021	34,264,806			34,264,806