CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Series A Preferred Stock	Preferred Stock Series A Preferred Stock	Preferred Stock Series B Preferred Stock	Common Stock	Common Stock Series A Preferred Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2021			7	54,745	199,502,183
Beginning balance at Dec. 31, 2021	$ 95,818		$ 0	$ 1	$ 1,995			$ 225,537	$ 0	$ (131,667)
Treasury stock, beginning balance (in shares) at Dec. 31, 2021							$ (48)
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)
Ending balance (in shares) at Mar. 31, 2022			7	54,745	215,752,926
Ending balance at Mar. 31, 2022	131,129		$ 0	$ 1	$ 2,158			278,704	0	(149,686)
Treasury stock, ending balance (in shares) at Mar. 31, 2022							(48)
Beginning balance (in shares) at Dec. 31, 2021			7	54,745	199,502,183
Beginning balance at Dec. 31, 2021	95,818		$ 0	$ 1	$ 1,995			225,537	0	(131,667)
Treasury stock, beginning balance (in shares) at Dec. 31, 2021							(48)
Increase (Decrease) in Stockholders' Equity
Net loss	(37,490)
Ending balance (in shares) at Jun. 30, 2022			0	54,745	216,271,262
Ending balance at Jun. 30, 2022	114,108		$ 0	$ 1	$ 2,163			281,139	10	(169,157)
Treasury stock, ending balance (in shares) at Jun. 30, 2022							(48)
Beginning balance (in shares) at Mar. 31, 2022			7	54,745	215,752,926
Beginning balance at Mar. 31, 2022	131,129		$ 0	$ 1	$ 2,158			278,704	0	(149,686)
Treasury stock, beginning balance (in shares) at Mar. 31, 2022							(48)
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
Series A convertible preferred stock conversion		$ 0
Other comprehensive income (loss)	10								10
Net loss	(19,471)									(19,471)
Ending balance (in shares) at Jun. 30, 2022			0	54,745	216,271,262
Ending balance at Jun. 30, 2022	114,108		$ 0	$ 1	$ 2,163			281,139	10	(169,157)
Treasury stock, ending balance (in shares) at Jun. 30, 2022							(48)
Beginning balance (in shares) at Dec. 31, 2022			0	54,745	221,721,182
Beginning balance at Dec. 31, 2022	84,052		$ 0	$ 1	$ 2,217			294,874	26	(213,018)
Treasury stock, beginning balance (in shares) at Dec. 31, 2022	48						(48)
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)
Ending balance (in shares) at Mar. 31, 2023			0	54,745	226,548,693
Ending balance at Mar. 31, 2023	75,800		$ 0	$ 1	$ 2,265			303,073	25	(229,516)
Treasury stock, ending balance (in shares) at Mar. 31, 2023							(48)
Beginning balance (in shares) at Dec. 31, 2022			0	54,745	221,721,182
Beginning balance at Dec. 31, 2022	84,052		$ 0	$ 1	$ 2,217			294,874	26	(213,018)
Treasury stock, beginning balance (in shares) at Dec. 31, 2022	48						(48)
Increase (Decrease) in Stockholders' Equity
Net loss	(39,423)
Ending balance (in shares) at Jun. 30, 2023			0	54,745	256,608,552
Ending balance at Jun. 30, 2023	70,281		$ 0	$ 1	$ 2,566			320,181	22	(252,441)
Treasury stock, ending balance (in shares) at Jun. 30, 2023	48						(48)
Beginning balance (in shares) at Mar. 31, 2023			0	54,745	226,548,693
Beginning balance at Mar. 31, 2023	75,800		$ 0	$ 1	$ 2,265			303,073	25	(229,516)
Treasury stock, beginning balance (in shares) at Mar. 31, 2023							(48)
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)
Ending balance (in shares) at Jun. 30, 2023			0	54,745	256,608,552
Ending balance at Jun. 30, 2023	70,281		$ 0	$ 1	$ 2,566			$ 320,181	$ 22	$ (252,441)
Treasury stock, ending balance (in shares) at Jun. 30, 2023	$ 48						$ (48)