STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Unrestricted Shares of Common Stock	Preferred Stock	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total
Balance at Dec. 31, 2019	$ 1	$ 1	$ 51,490	$ (49,926)	$ 1,566
Balance (in shares) at Dec. 31, 2019	8,877	105
Common stock issued in exchange for exercise of options on a cashless basis			256		256
Stock-based compensation			256		256
Net loss				(1,664)	(1,664)
Balance at Mar. 31, 2020	$ 1	$ 1	51,746	(51,590)	158
Balance (in shares) at Mar. 31, 2020	8,877	105
Balance at Dec. 31, 2020	$ 1	$ 1	64,716	(57,084)	7,634
Balance (in shares) at Dec. 31, 2020	10,130	90
Issuance of common stock for cash, net of transaction expenses			16,534		16,534
Issuance of common stock for cash, net of transaction expenses (in shares)	472
Common stock issued in exchange for exercise of warrants on a cashless basis			148		148
Common stock issued in exchange for exercise of warrants on a cashless basis (in shares)	22
Common stock issued in exchange for exercise of options on a cashless basis			1,781		1,781
Common stock issued upon exercise of warrants and options on a cashless basis (in shares)	121
Common stock issued upon settlement of restricted stock units (in shares)	92
Issuance of common stock for services (in shares)	2
Surrender of stock to cover tax liability on settlement of employee shared-based awards			(373)		(373)
Surrender of stock to cover tax liability on settlement of employee shared-based awards (in share)	(16)
Stock-based compensation			1,781		1,781
Net loss				(2,765)	(2,765)
Balance at Mar. 31, 2021	$ 1	$ 1	$ 82,806	$ (59,849)	$ 22,959
Balance (in shares) at Mar. 31, 2021	10,823	90