Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Balances at Dec. 31, 2020	$ 21,147		$ 174,349	$ (153,202)
Balance (in shares) at Dec. 31, 2020		63
Common stock issued, net	15,153		15,153
Common stock issued, net (in shares)		78
Warrants issued, net	132		132
Restricted stock awards canceled		(2)
Common stock issued pursuant to the vesting of restricted stock units and purchases under employee stock purchase plan	74		74
Common stock issued pursuant to the vesting of restricted stock units and purchases under employee stock purchase plan (in shares)		1
Stock-based compensation	2,237		2,237
Net loss	(25,070)			(25,070)
Balances at Dec. 31, 2021	13,673		191,945	(178,272)
Balance (in shares) at Dec. 31, 2021		140
Common stock issued, net	11,638		11,638
Common stock issued, net (in shares)		1,576
Warrants issued, net	4,658		4,658
Warrants exercised	5,704		5,704
Warrants exercised (in shares)		446
Restricted stock awards canceled		(1)
Common stock issued pursuant to the vesting of restricted stock units and purchases under employee stock purchase plan	5		5
Stock-based compensation	447		447
Net loss	(26,865)			(26,865)
Balances at Dec. 31, 2022	$ 9,260		$ 214,397	$ (205,137)
Balance (in shares) at Dec. 31, 2022		2,161