Consolidated Statements of Stockholders' Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	ATM Program [Member] Common Stock [Member]	ATM Program [Member] Additional Paid-in Capital [Member]	ATM Program [Member] Retained Earnings [Member]	ATM Program [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2018					17,089,000
Balance at Dec. 31, 2018					$ 171	$ 119,764	$ (114,981)	$ 4,954
Net loss							(4,189)	(4,189)
Vesting of restricted stock awards (in shares)					6,000
Vesting of restricted stock awards						10		10
Stock-based compensation expense related to employee and director stock options						107		107
Stock-based compensation expense related to non-employee stock options						7		7
Reclassification of Warrant Liability to Equity – see Note 2						412	(356)	56
Debt discount associated with convertible note – beneficial conversion feature						184		184
Balance (in shares) at Mar. 31, 2019					17,095,000
Balance at Mar. 31, 2019					$ 171	120,484	(119,526)	1,129
Balance (in shares) at Dec. 31, 2018					17,089,000
Balance at Dec. 31, 2018					$ 171	119,764	(114,981)	4,954
Net loss								$ (6,690)
Balance (in shares) at Jun. 30, 2019					20,733,000
Issuance of common stock for option exercises (in shares)								83,000
Balance at Jun. 30, 2019					$ 207	123,518	(122,056)	$ 1,669
Balance (in shares) at Mar. 31, 2019					17,095,000
Balance at Mar. 31, 2019					$ 171	120,484	(119,526)	1,129
Net loss							(2,501)	(2,501)
Issuance of common stock in connection with exercise of warrants (in shares)					286,000
Issuance of common stock in connection with exercise of warrants					$ 3	443		446
Stock-based compensation expense related to employee and director stock options						7		7
Stock-based compensation expense related to non-employee stock options						95		95
Issuance of common stock, net of offering costs (in shares)					3,269,000
Issuance of common stock, net of offering costs					$ 33	2,434		2,467
Stock option modification						21		21
Balance (in shares) at Jun. 30, 2019					20,733,000
Down round feature adjustment related to warrants						29	(29)
Issuance of common stock for option exercises (in shares)					83,000			83,000
Issuance of common stock for option exercises						189		$ 189
Debt discount associated with convertible note – beneficial conversion feature						(184)		(184)
Balance at Jun. 30, 2019					$ 207	123,518	(122,056)	1,669
Balance (in shares) at Dec. 31, 2019					27,938,000
Balance at Dec. 31, 2019					$ 279	125,718	(125,024)	973
Net loss							(1,582)	(1,582)
Issuance of common stock in connection with exercise of warrants (in shares)					299,000
Issuance of common stock in connection with exercise of warrants					$ 3	198		201
Vesting of restricted stock awards (in shares)					2,000
Vesting of restricted stock awards						2		2
Stock-based compensation expense related to employee and director stock options						45		45
Stock-based compensation expense related to non-employee stock options						12		12
Balance (in shares) at Mar. 31, 2020					28,239,000
Balance at Mar. 31, 2020					$ 282	125,975	(126,606)	(349)
Balance (in shares) at Dec. 31, 2019					27,938,000
Balance at Dec. 31, 2019					$ 279	125,718	(125,024)	973
Net loss								(6,064)
Balance (in shares) at Jun. 30, 2020					34,648,000
Balance at Jun. 30, 2020					$ 346	131,725	(131,088)	983
Balance (in shares) at Mar. 31, 2020					28,239,000
Balance at Mar. 31, 2020					$ 282	125,975	(126,606)	(349)
Net loss							(4,482)	(4,482)
Issuance of common stock in connection with exercise of warrants (in shares)					571,000
Issuance of common stock in connection with exercise of warrants					$ 6	462		468
Stock-based compensation expense related to employee and director stock options						92		92
Stock-based compensation expense related to non-employee stock options						(2)		(2)
Issuance of common stock, net of offering costs (in shares)	5,838,000			5,836,792
Issuance of common stock, net of offering costs	$ 58	$ 5,162		$ 5,220
Stock option modification						36		36
Balance (in shares) at Jun. 30, 2020					34,648,000
Balance at Jun. 30, 2020					$ 346	$ 131,725	$ (131,088)	$ 983