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
Sale of common stock, net of issuance costs	$ 87,000	22,723,000		22,810,000
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
Return of restricted stock awards for tax withholdings		(8,000)		(8,000)
Return of restricted stock awards for tax withholdings, shares	(2,511)
Forfeiture of restricted stock awards (in shares)	(4,010)
Exercise stock options	$ 1,000	86,000		87,000
Exercise of stock options (in shares)	27,382
Issuance of stock awards, net of tax withholding (in shares)	19,578
Stock-based compensation		3,475,000		3,475,000
Net loss			(22,181,000)	(22,181,000)
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	$ 83,000	26,223,000		26,306,000
Sale of common stock, net of issuance costs (in shares)	8,275,060
Exercise of warrants	$ 1,000	290,000		291,000
Exercise of warrants (in shares)	52,000
Return of restricted stock awards for tax withholdings		(106,000)		(106,000)
Return of restricted stock awards for tax withholdings, shares	(25,424)
Forfeiture of restricted stock awards (in shares)	(1,047)
Exercise stock options		322,000		$ 322,000
Exercise of stock options (in shares)	99,517			99,517
Issuance of inducement stock awards (in shares)	23,732
Stock-based compensation		2,882,000		$ 2,882,000
Net loss			(23,155,000)	(23,155,000)
Balances at Dec. 31, 2021	$ 271,000	$ 227,983,000	$ (202,857,000)	$ 25,397,000
Balances (in shares) at Dec. 31, 2021	27,112,299