CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	Total	ATM Offering	Common Stock	Common Stock ATM Offering	Additional Paid-In Capital	Additional Paid-In Capital ATM Offering	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2022			33,477
Beginning balance at Dec. 31, 2022	$ 211,605		$ 9		$ 1,182,568		$ 5,598	$ (976,570)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)			10
Exercise of common stock options	54				54
Stock-based compensation	31,561				31,561
Settlement of restricted stock (in shares)			2,004
Issuance of common stock, net of issuance costs - ATM Offering Program (as defined below) (in shares)			2,755
Issuance of common stock, net of issuance costs - ATM Offering Program (as defined below)	15,171				15,171
Issuance of common stock pursuant to the ESPP (in shares)			282
Issuance of common stock pursuant to the 2018 ESPP (as defined below)	1,104				1,104
Other comprehensive income (loss)	(294)						(294)
Net Income (Loss)	(33,866)							(33,866)
Ending balance (in shares) at Sep. 30, 2023			38,528
Ending balance at Sep. 30, 2023	225,335		$ 9		1,230,458		5,304	(1,010,436)
Beginning balance (in shares) at Jun. 30, 2023			37,088
Beginning balance at Jun. 30, 2023	236,112		$ 9		1,219,530		3,043	(986,470)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)			6
Exercise of common stock options	44				44
Stock-based compensation	10,884				10,884
Settlement of restricted stock (in shares)			1,434
Other comprehensive income (loss)	2,261						2,261
Net Income (Loss)	(23,966)							(23,966)
Ending balance (in shares) at Sep. 30, 2023			38,528
Ending balance at Sep. 30, 2023	225,335		$ 9		1,230,458		5,304	(1,010,436)
Beginning balance (in shares) at Dec. 31, 2023			39,728
Beginning balance at Dec. 31, 2023	134,798		$ 9		1,243,594		2,467	(1,111,272)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)			3
Exercise of common stock options	5				5
Stock-based compensation	35,396				35,396
Settlement of restricted stock (in shares)			2,869
Issuance of common stock, net of issuance costs - ATM Offering Program (as defined below) (in shares)			3,592	3,908
Issuance of common stock, net of issuance costs - ATM Offering Program (as defined below)	27,451	$ 48,151			27,451	$ 48,151
Issuance of common stock pursuant to the ESPP (in shares)			242
Issuance of common stock pursuant to the 2018 ESPP (as defined below)	1,461				1,461
Termination of capped calls related to 2020 Convertible Senior Notes	115				115
Other comprehensive income (loss)	(3,965)						(3,965)
Net Income (Loss)	(173,715)							(173,715)
Ending balance (in shares) at Sep. 30, 2024			50,342
Ending balance at Sep. 30, 2024	69,697		$ 9		1,356,173		(1,498)	(1,284,987)
Beginning balance (in shares) at Jun. 30, 2024			49,402
Beginning balance at Jun. 30, 2024	210,033		$ 9		1,346,876		2,953	(1,139,805)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	9,297				9,297
Settlement of restricted stock (in shares)			940
Other comprehensive income (loss)	(4,451)						(4,451)
Net Income (Loss)	(145,182)							(145,182)
Ending balance (in shares) at Sep. 30, 2024			50,342
Ending balance at Sep. 30, 2024	$ 69,697		$ 9		$ 1,356,173		$ (1,498)	$ (1,284,987)