CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Series A Convertible Preferred Stock	Series B Convertible Preferred Stock	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, 2021					7	54,745
Common stock, beginning balance (in shares) at Dec. 31, 2021							199,502,183
Beginning balance at Dec. 31, 2021	$ 95,818				$ 0	$ 1	$ 1,995	$ (48)	$ 225,537	$ 0	$ (131,667)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	3,299								3,299
Issuance of common stock for stock option exercises and restricted stock unit vesting, net (in shares)							277,323
Issuance of common stock for stock option exercises and restricted stock unit vesting, net	180						$ 3		177
Issuance of common stock for capital raises, net (in shares)							15,973,420
Issuance of common stock for capital raises, net	49,851						$ 160		49,691
Net loss	(18,019)										(18,019)
Convertible preferred stock, ending balance (in shares) at Mar. 31, 2022					7	54,745
Common stock, ending balance (in shares) at Mar. 31, 2022							215,752,926
Ending balance at Mar. 31, 2022	131,129				$ 0	$ 1	$ 2,158	(48)	278,704	0	(149,686)
Convertible preferred stock, beginning balance (in shares) at Dec. 31, 2021					7	54,745
Common stock, beginning balance (in shares) at Dec. 31, 2021							199,502,183
Beginning balance at Dec. 31, 2021	95,818				$ 0	$ 1	$ 1,995	(48)	225,537	0	(131,667)
Increase (Decrease) in Stockholders' Equity
Net loss	(59,412)
Convertible preferred stock, ending balance (in shares) at Sep. 30, 2022					0	54,745
Common stock, ending balance (in shares) at Sep. 30, 2022							216,809,937
Ending balance at Sep. 30, 2022	95,303				$ 0	$ 1	$ 2,168	(48)	284,231	30	(191,079)
Convertible preferred stock, beginning balance (in shares) at Mar. 31, 2022					7	54,745
Common stock, beginning balance (in shares) at Mar. 31, 2022							215,752,926
Beginning balance at Mar. 31, 2022	131,129				$ 0	$ 1	$ 2,158	(48)	278,704	0	(149,686)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	2,079								2,079
Issuance of common stock for stock option exercises and restricted stock unit vesting, net (in shares)							515,221
Issuance of common stock for stock option exercises and restricted stock unit vesting, net	361						$ 5		356
Series A convertible preferred stock conversion (in shares)				(7)			3,115
Other comprehensive income (loss)	10									10
Net loss	(19,471)										(19,471)
Convertible preferred stock, ending balance (in shares) at Jun. 30, 2022					0	54,745
Common stock, ending balance (in shares) at Jun. 30, 2022							216,271,262
Ending balance at Jun. 30, 2022	114,108				$ 0	$ 1	$ 2,163	(48)	281,139	10	(169,157)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	2,495								2,495
Issuance of common stock for stock option exercises and restricted stock unit vesting, net (in shares)							538,675
Issuance of common stock for stock option exercises and restricted stock unit vesting, net	602						$ 5		597
Other comprehensive income (loss)	20									20
Net loss	(21,922)										(21,922)
Convertible preferred stock, ending balance (in shares) at Sep. 30, 2022					0	54,745
Common stock, ending balance (in shares) at Sep. 30, 2022							216,809,937
Ending balance at Sep. 30, 2022	$ 95,303				$ 0	$ 1	$ 2,168	(48)	284,231	30	(191,079)
Convertible preferred stock, beginning balance (in shares) at Dec. 31, 2022		0	54,745		0	54,745
Common stock, beginning balance (in shares) at Dec. 31, 2022	221,599,682						221,721,182
Beginning balance at Dec. 31, 2022	$ 84,052				$ 0	$ 1	$ 2,217	(48)	294,874	26	(213,018)
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	(16,498)										(16,498)
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	$ 75,800				$ 0	$ 1	$ 2,265	(48)	303,073	25	(229,516)
Convertible preferred stock, beginning balance (in shares) at Dec. 31, 2022		0	54,745		0	54,745
Common stock, beginning balance (in shares) at Dec. 31, 2022	221,599,682						221,721,182
Beginning balance at Dec. 31, 2022	$ 84,052				$ 0	$ 1	$ 2,217	(48)	294,874	26	(213,018)
Increase (Decrease) in Stockholders' Equity
Net loss	$ (53,585)
Convertible preferred stock, ending balance (in shares) at Sep. 30, 2023		0	54,745		0	54,745
Common stock, ending balance (in shares) at Sep. 30, 2023	256,499,987						256,621,487
Ending balance at Sep. 30, 2023	$ 58,395				$ 0	$ 1	$ 2,566	(48)	322,452	27	(266,603)
Convertible preferred stock, beginning balance (in shares) at Mar. 31, 2023					0	54,745
Common stock, beginning balance (in shares) at Mar. 31, 2023							226,548,693
Beginning balance at Mar. 31, 2023	75,800				$ 0	$ 1	$ 2,265	(48)	303,073	25	(229,516)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	2,632								2,632
Issuance of common stock for stock option exercises and restricted stock unit vesting, net (in shares)							59,859
Issuance of common stock for stock option exercises and restricted stock unit vesting, net	10						$ 1		9
Issuance of common stock for capital raises, net (in shares)							30,000,000
Issuance of common stock for capital raises, net	14,767						$ 300		14,467
Other comprehensive income (loss)	(3)									(3)
Net loss	(22,925)										(22,925)
Convertible preferred stock, ending balance (in shares) at Jun. 30, 2023					0	54,745
Common stock, ending balance (in shares) at Jun. 30, 2023							256,608,552
Ending balance at Jun. 30, 2023	70,281				$ 0	$ 1	$ 2,566	(48)	320,181	22	(252,441)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense	2,174								2,174
Issuance of common stock for stock option exercises and restricted stock unit vesting, net (in shares)							12,935
Issuance of common stock for stock option exercises and restricted stock unit vesting, net	97								97
Other comprehensive income (loss)	5									5
Net loss	$ (14,162)										(14,162)
Convertible preferred stock, ending balance (in shares) at Sep. 30, 2023		0	54,745		0	54,745
Common stock, ending balance (in shares) at Sep. 30, 2023	256,499,987						256,621,487
Ending balance at Sep. 30, 2023	$ 58,395				$ 0	$ 1	$ 2,566	$ (48)	$ 322,452	$ 27	$ (266,603)