Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Gain (Loss)	Accumulated Deficit
Increase (Decrease) in Stockholders' Equity
Beginning balance (in shares)		62,816,039
Beginning balance at Dec. 31, 2020	$ 73,376	$ 63	$ 785,673	$ 0	$ (712,360)
Increase (Decrease) in Stockholders' Equity
Share-based compensation	2,584		2,584
Exercise of stock options	3,530	$ 1	3,529
Exercise of stock options (in shares)		710,132
Employee stock purchase plan purchases	330		330
Employee stock purchase plan purchases (in shares)		259,837
RSU stock issuance (in shares)		168,752
Issuance of common stock related to asset acquisition	43,445	$ 9	43,436
Issuance of common stock related to asset acquisition (in shares)		8,723,769
Issuance of common stock, net of issuance costs	107,842	$ 13	107,829
Issuance of common stock, net of issuance costs (in shares)		13,529,750
Comprehensive loss:
Unrealized loss on investments, net	(43)			(43)
Net loss	(97,415)				(97,415)
Comprehensive loss	(97,458)
Ending balance at Mar. 31, 2021	133,649	$ 86	943,381	(43)	(809,775)
Ending balance (in shares) at Mar. 31, 2021		86,208,279
Increase (Decrease) in Stockholders' Equity
Beginning balance (in shares)		86,208,279
Beginning balance (in shares)		86,884,266
Beginning balance at Dec. 31, 2021	68,252	$ 87	953,782	(21)	(885,596)
Increase (Decrease) in Stockholders' Equity
Share-based compensation	3,708		3,708
Exercise of stock options	102		102
Exercise of stock options (in shares)		34,406
Employee stock purchase plan purchases	555		555
Employee stock purchase plan purchases (in shares)		383,981
RSU stock issuance (in shares)		133,527
Comprehensive loss:
Unrealized loss on investments, net	(52)			(52)
Net loss	(24,767)				(24,767)
Comprehensive loss	(24,819)
Ending balance at Mar. 31, 2022	$ 47,798	$ 87	$ 958,147	$ (73)	$ (910,363)
Ending balance (in shares) at Mar. 31, 2022		87,436,180
Increase (Decrease) in Stockholders' Equity
Beginning balance (in shares)		87,436,180