CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	ATM	Private Placement	Follow On Offering	Common Stock	Common Stock ATM	Common Stock Private Placement	Common Stock Follow On Offering	Additional Paid-in Capital	Additional Paid-in Capital ATM	Additional Paid-in Capital Private Placement	Additional Paid-in Capital Follow On Offering	Accumulated Other Comprehensive Gain (Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2019	$ 258,507				$ 4				$ 457,994				$ 183	$ (199,674)
Beginning balance, Shares at Dec. 31, 2019					45,116,742
Vesting of common stock from option exercises	24								24
Vesting of common stock from option exercises, Shares					18,575
Issuance of common stock from option exercises	176								176
Issuance of common stock from option exercises, Shares					46,410
Issuance of common stock pursuant to employee stock purchase plan	938								938
Issuance of common stock pursuant to employee stock purchase plan, Shares					83,848
Issuance of common stock, net of discounts and issuance costs			$ 51,979				$ 1				$ 51,978
Issuance of common stock, net of discounts and issuance costs, Shares							5,000,000
Stock-based compensation	13,248								13,248
Other comprehensive loss	(183)												(183)
Net loss	(128,694)													(128,694)
Ending balance at Dec. 31, 2020	195,995				$ 5				524,358					(328,368)
Ending balance, Shares at Dec. 31, 2020					50,265,575
Vesting of common stock from option exercises	13								13
Vesting of common stock from option exercises, Shares					3,091
Issuance of common stock from option exercises	145								145
Issuance of common stock from option exercises, Shares					59,465
Issuance of common stock pursuant to employee stock purchase plan	826								826
Issuance of common stock pursuant to employee stock purchase plan, Shares					110,923
Issuance of common stock, net of discounts and issuance costs		$ 1,454		$ 49,744				$ 1		$ 1,454		$ 49,743
Issuance of common stock, net of discounts and issuance costs, Shares						114,914		6,596,306
Stock-based compensation	17,245								17,245
Other comprehensive loss	(7)												(7)
Net loss	(95,764)													(95,764)
Ending balance at Dec. 31, 2021	$ 169,651				$ 6				$ 593,784				$ (7)	$ (424,132)
Ending balance, Shares at Dec. 31, 2021					57,150,274