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)	(4,010)
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)
Stock-based compensation		1,950,000		1,950,000
Net loss			(9,788,000)	(9,788,000)
Balances at Jun. 30, 2020	$ 186,000	196,761,000	(167,309,000)	29,638,000
Balances (in shares) at Jun. 30, 2020	18,641,501
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
Forfeiture of restricted stock awards (in shares)	(681)
Issuance cost in connection with sale of common stock		(32,000)		(32,000)
Return of restricted stock awards for tax withholdings		(8,000)		(8,000)
Return of restricted stock awards for tax withholdings, shares	(2,511)
Stock-based compensation		906,000		906,000
Net loss			(4,710,000)	(4,710,000)
Balances at Jun. 30, 2020	$ 186,000	196,761,000	(167,309,000)	29,638,000
Balances (in shares) at Jun. 30, 2020	18,641,501
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
Forfeiture of restricted stock awards (in shares)	(924)
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
Return of restricted stock awards for tax withholdings		(106,000)		(106,000)
Return of restricted stock awards for tax withholdings, shares	(25,424)
Exercise stock options		154,000		$ 154,000
Exercise of stock options (in shares)	46,134			46,134
Issuance of inducement stock awards (in shares)	23,732
Stock-based compensation		1,749,000		$ 1,749,000
Net loss			(11,689,000)	(11,689,000)
Balances at Jun. 30, 2021	$ 249,000	219,761,000	(191,391,000)	28,619,000
Balances (in shares) at Jun. 30, 2021	24,937,826
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
Forfeiture of restricted stock awards (in shares)	(924)
Return of restricted stock awards for tax withholdings		(106,000)		(106,000)
Return of restricted stock awards for tax withholdings, shares	(25,424)
Issuance of inducement stock awards (in shares)	23,732
Stock-based compensation		907,000		907,000
Net loss			(6,194,000)	(6,194,000)
Balances at Jun. 30, 2021	$ 249,000	$ 219,761,000	$ (191,391,000)	$ 28,619,000
Balances (in shares) at Jun. 30, 2021	24,937,826