CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Series A Convertible Preferred Stock	Series B Convertible Preferred Stock	Preferred Stock Series A Convertible Preferred Stock	Preferred Stock Series B Convertible Preferred Stock	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Convertible preferred stock, beginning balance (in shares) at Dec. 31, 2022				0	54,745
Common stock, beginning balance (in shares) at Dec. 31, 2022						221,721,182
Beginning balance at Dec. 31, 2022	$ 73,981			$ 0	$ 1	$ 2,217	$ (48)	$ 294,874	$ 26	$ (223,089)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	2,689							2,689
Issuance of common stock for stock option exercises and restricted stock unit vesting, net (in shares)						348,555
Issuance of common stock for stock option exercises and restricted stock unit vesting, net	(1)					$ 3		(4)
Issuance of common stock for capital raises, net (in shares)						4,478,956
Issuance of common stock for capital raises, net	5,559					$ 45		5,514
Other comprehensive income (loss)	(1)								(1)
Net loss	(17,326)									(17,326)
Convertible preferred stock, ending balance (in shares) at Mar. 31, 2023				0	54,745
Common stock, ending balance (in shares) at Mar. 31, 2023						226,548,693
Ending balance at Mar. 31, 2023	$ 64,901			$ 0	$ 1	$ 2,265	(48)	303,073	25	(240,415)
Convertible preferred stock, beginning balance (in shares) at Dec. 31, 2023		0	54,745	0	54,745
Common stock, beginning balance (in shares) at Dec. 31, 2023	256,566,804					256,688,304
Beginning balance at Dec. 31, 2023	$ 40,564			$ 0	$ 1	$ 2,567	(48)	324,191	20	(286,167)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	1,761							1,761
Issuance of common stock for stock option exercises and restricted stock unit vesting, net (in shares)						758,460
Issuance of common stock for stock option exercises and restricted stock unit vesting, net	(145)					$ 8		(153)
Other comprehensive income (loss)	5								5
Net loss	$ (11,924)									(11,924)
Convertible preferred stock, ending balance (in shares) at Mar. 31, 2024		0	54,745	0	54,745
Common stock, ending balance (in shares) at Mar. 31, 2024	257,325,264					257,446,764
Ending balance at Mar. 31, 2024	$ 30,261			$ 0	$ 1	$ 2,575	$ (48)	$ 325,799	$ 25	$ (298,091)