Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2019	$ 699,135	$ 15	$ 2,402,945	$ (1,704,122)	$ 297
Beginning balance (in shares) at Dec. 31, 2019		155,275,300
Issuance of common stock in public offering, net of issuance costs	44,280		44,280
Issuance of common stock in public offering, net of issuance costs (in shares)		1,156,626
Issuance of common stock from exercise of stock options and units	73,834	$ 1	73,833
Issuance of common stock from exercise of stock options and units (in shares)		2,827,586
Issuance of common stock pursuant to employee stock purchase plan	7,162		7,162
Issuance of common stock pursuant to employee stock purchase plan (in shares)		378,259
Net loss	(281,584)			(281,584)
Stock-based compensation	84,443		84,443
Other comprehensive income	(261)				(261)
Ending balance at Dec. 31, 2020	627,009	$ 16	2,612,663	(1,985,706)	36
Ending balance (in shares) at Dec. 31, 2020		159,637,771
Issuance of common stock from exercise of stock options	12,850		12,850
Issuance of common stock from exercise of stock options (in shares)		1,078,074
Issuance of common stock pursuant to employee stock purchase plan	5,312		5,312
Issuance of common stock pursuant to employee stock purchase plan (in shares)		296,850
Net loss	(167,870)			(167,870)
Stock-based compensation	63,821		63,821
Other comprehensive income	(228)				(228)
Ending balance at Dec. 31, 2021	$ 540,894	$ 16	2,694,646	(2,153,576)	(192)
Ending balance (in shares) at Dec. 31, 2021		161,012,695
Issuance of common stock from exercise of stock options (in shares)	226,943
Issuance of common stock from exercise of stock options and units	$ 3,705		3,705
Issuance of common stock from exercise of stock options and units (in shares)		721,652
Issuance of common stock pursuant to employee stock purchase plan	4,494		4,494
Issuance of common stock pursuant to employee stock purchase plan (in shares)		330,525
Net loss	(215,975)			(215,975)
Stock-based compensation	68,078		68,078
Other comprehensive income	(783)				(783)
Ending balance at Dec. 31, 2022	$ 400,413	$ 16	$ 2,770,923	$ (2,369,551)	$ (975)
Ending balance (in shares) at Dec. 31, 2022		162,064,872