Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands		Preferred Stock [Member] Convertible Preferred Stock [Member]	Common Stock [Member]		Additional Paid-in Capital [Member]	[1]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2020			$ 2	[1]	$ 505,547		$ (478,211)	$ 27,338
Balance, shares at Dec. 31, 2020			2,194,284	[1]
Issuance of common stock and pre-funded warrants through underwritten offering, net of issuance costs of $173				[1]	1,255			1,255
Issuance of common stock and pre-funded warrants through underwritten offering, shares	[1]		266,800
Issuance of common stock upon exercise of warrants			$ 1	[1]	6,670			6,671
Issuance of common stock upon exercise of warrants, shares	[1]		428,542
Reclassification of warrant liability upon exercise				[1]	8,964			8,964
Issuance of common stock upon exercise of prefunded warrants				[1]	8			8
Issuance of common stock upon exercise of pre-funded warrants, shares	[1]		306,358
Stock-based compensation expense				[1]	5,600			5,600
Stock option exercises				[1]	3			3
Stock option exercises, shares	[1]		100
Purchase of ESPP shares				[1]	55			55
Purchase of ESPP shares, shares	[1]		4,076
Vesting of restricted stock units				[1]
Vesting of restricted stock units, shares	[1]		125,063
Shares withheld for tax withholding				[1]	(463)			(463)
Shares withheld for tax withholding, shares	[1]		(24,326)
Forfeiture of restricted stock awards				[1]
Forfeiture of restricted stock awards, shares	[1]		(1,518)
Net loss				[1]			(30,187)	(30,187)
Balance at Dec. 31, 2021			$ 3	[1]	527,639		(508,398)	19,244
Balance, shares at Dec. 31, 2021			3,299,379	[1]
Issuance of common stock and pre-funded warrants through underwritten offering, net of issuance costs of $173				[1]	1,840			1,840
Issuance of common stock and pre-funded warrants through underwritten offering, shares	[1]		445,500
Issuance of common stock upon exercise of prefunded warrants			$ 3	[1]				3
Issuance of common stock upon exercise of pre-funded warrants, shares	[1]		2,722,818
Stock-based compensation expense				[1]	1,857			1,857
Vesting of restricted stock units				[1]
Vesting of restricted stock units, shares	[1]		137,259
Shares withheld for tax withholding				[1]	(181)			(181)
Shares withheld for tax withholding, shares	[1]		(22,732)
Net loss				[1]			(7,833)	(7,833)
Issuance of preferred stock and warrants through underwritten offering, net of issuance costs of $184				[1]	1,685			1,685
Issuance of preferred stock and warrants through underwritten offering, net of issuance costs, shares		5,000
Issuance of common stock upon conversion of preferred stock			$ 1	[1]	(1)
Issuance of common stock upon conversion of preferred stock, shares		(5,000)	655,738	[1]
Fractional shares issued for reverse stock split				[1]
Fractional shares issued for reverse stock split, shares	[1]		17,024
Purchase of ESPP shares				[1]	3			3
Purchase of ESPP shares, shares	[1]		3,200
Balance at Dec. 31, 2022			$ 7	[1]	$ 532,842		$ (516,231)	$ 16,618
Balance, shares at Dec. 31, 2022			7,258,186	[1]

[1] Giving retroactive effect to the 1-for-25 reverse stock split effectuated on May 16, 2022