CONSOLIDATED STATEMENTS OF STOCKHOLDERS EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Total
Balance, beginning at Dec. 31, 2019	$ 17	$ 1,104,706	$ 2,619	$ (1,013,316)	$ 94,026
Balance (in shares) at Dec. 31, 2019	16,972,077
Increase (Decrease) in Stockholders' Equity
Shares issued under stock option and employee stock purchase plans		434			434
Shares issued under stock option and employee stock purchase plans (in shares)	122,076
Shares issued in connection with at the market agreement	$ 8	29,423			29,431
Shares issued in connection with at the market agreement (in shares)	7,125,004
Shares issued in underwritten offering, net	$ 15	141,346			141,361
Shares issued in underwritten offering, net (in shares)	15,384,614
Stock-based compensation		3,915			3,915
Unrealized loss on marketable securities			(30)		(30)
Net loss				(59,780)	(59,780)
Balance, ending at Dec. 31, 2020	$ 40	1,279,824	2,589	(1,073,096)	209,357
Balance (in shares) at Dec. 31, 2020	39,603,771
Increase (Decrease) in Stockholders' Equity
Shares issued under stock option and employee stock purchase plans		2,479			2,479
Shares issued under stock option and employee stock purchase plans (in shares)	281,189
Shares issued in underwritten offering, net	$ 7	269,886			269,893
Shares issued in underwritten offering, net (in shares)	6,845,238
Stock-based compensation		8,953			8,953
Unrealized loss on marketable securities			(695)		(695)
Net loss				(70,511)	(70,511)
Balance, ending at Dec. 31, 2021	$ 47	1,561,142	1,894	(1,143,607)	$ 419,476
Balance (in shares) at Dec. 31, 2021	46,730,198				46,730,198
Increase (Decrease) in Stockholders' Equity
Shares issued under stock option and employee stock purchase plans		4,076			$ 4,076
Shares issued under stock option and employee stock purchase plans (in shares)	470,497
Stock-based compensation		15,611			15,611
Unrealized loss on marketable securities			(634)		(634)
Net loss				(112,325)	(112,325)
Balance, ending at Dec. 31, 2022	$ 47	$ 1,580,829	$ 1,260	$ (1,255,932)	$ 326,204
Balance (in shares) at Dec. 31, 2022	47,200,695				47,200,695