Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance at Dec. 31, 2021	$ 72,156	$ 3		$ 601,523	$ (529,370)
Beginning balance, shares at Dec. 31, 2021		30,511,226	1
Cashless exercise of common stock warrants, shares		7,359,285	18
401(k) matching contribution	254			254
401(k) matching contribution, shares		16,756
Vesting of restricted shares, shares		222,595
Stock-based compensation	5,775			5,775
ESPP shares issued	515			515
ESPP shares issued, shares		39,951
Net loss	(40,665)				(40,665)
Ending balance at Mar. 31, 2022	38,035	$ 3		608,067	(570,035)
Ending balance, shares at Mar. 31, 2022		38,149,813	19
Beginning balance at Dec. 31, 2022	$ (74,814)	$ 3		652,276	(727,093)
Beginning balance, shares at Dec. 31, 2022	41,468,871	41,468,871	19
401(k) matching contribution	$ 456			456
401(k) matching contribution, shares		52,130
Vesting of restricted shares, shares		414,119
Stock-based compensation	7,048			7,048
ESPP shares issued	856			856
ESPP shares issued, shares		121,801
Issuance of common stock under ATM facility, shares		1,514,219
Issuance of common stock under ATM facility	14,073	$ 1		14,072
Net loss	(37,814)				(37,814)
Ending balance at Mar. 31, 2023	$ (90,195)	$ 4		$ 674,708	$ (764,907)
Ending balance, shares at Mar. 31, 2023	43,571,140	43,571,140	19