Consolidated Statements of Stockholders' Equity - USD ($)	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total
Balances at Dec. 31, 2019	$ 99,000	$ 172,015,000	$ (157,521,000)	$ 14,593,000
Balances (in shares) at Dec. 31, 2019	9,922,758
Forfeiture of restricted stock awards (in shares)	(3,329)
Sale of common stock, net of issuance costs	$ 87,000	22,755,000		22,842,000
Sale of common stock, net of issuance costs (in shares)	8,710,800
Exercise of warrants		81,000		81,000
Exercise of warrants (in shares)	14,464
Stock-based compensation		1,044,000		1,044,000
Net loss			(5,078,000)	(5,078,000)
Balances at Mar. 31, 2020	$ 186,000	195,895,000	(162,599,000)	33,482,000
Balances (in shares) at Mar. 31, 2020	18,644,693
Balances at Dec. 31, 2020	$ 187,000	198,372,000	(179,702,000)	18,857,000
Balances (in shares) at Dec. 31, 2020	18,688,461
Sale of common stock, net of issuance costs	$ 61,000	19,302,000		19,363,000
Sale of common stock, net of issuance costs (in shares)	6,153,847
Exercise of warrants	$ 1,000	290,000		291,000
Exercise of warrants (in shares)	52,000
Exercise stock options		154,000		$ 154,000
Exercise of stock options (in shares)	46,134			46,134
Stock-based compensation		842,000		$ 842,000
Net loss			(5,495,000)	(5,495,000)
Balances at Mar. 31, 2021	$ 249,000	$ 218,960,000	$ (185,197,000)	$ 34,012,000
Balances (in shares) at Mar. 31, 2021	24,940,442