CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning Balance (in shares) at Dec. 31, 2021		108,929
Beginning Balance at Dec. 31, 2021	$ 215,313	$ 1,089	$ 869,059	$ (306)	$ (654,529)
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Exercise of stock options (in shares)		1,090
Exercise of stock options	10,655	$ 11	10,644
Vesting of restricted stock units (in shares)		1,939
Vesting of restricted stock units	0	$ 19	(19)
Issuance of common stock under employee stock purchase plan (in shares)		443
Issuance of common stock under employee stock purchase plan	14,791	$ 5	14,786
Stock-based compensation	91,394		91,394
Other comprehensive income (loss)	(1,563)			(1,563)
Net loss	(70,735)				(70,735)
Ending Balance (in shares) at Sep. 30, 2022		112,401
Ending Balance at Sep. 30, 2022	259,855	$ 1,124	985,864	(1,869)	(725,264)
Beginning Balance (in shares) at Jun. 30, 2022		111,574
Beginning Balance at Jun. 30, 2022	237,525	$ 1,116	944,799	(1,856)	(706,534)
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Exercise of stock options (in shares)		158
Exercise of stock options	1,979	$ 2	1,977
Vesting of restricted stock units (in shares)		482
Vesting of restricted stock units	0	$ 4	(4)
Issuance of common stock under employee stock purchase plan (in shares)		187
Issuance of common stock under employee stock purchase plan	5,909	$ 2	5,907
Stock-based compensation	33,185		33,185
Other comprehensive income (loss)	(13)			(13)
Net loss	(18,730)				(18,730)
Ending Balance (in shares) at Sep. 30, 2022		112,401
Ending Balance at Sep. 30, 2022	$ 259,855	$ 1,124	985,864	(1,869)	(725,264)
Beginning Balance (in shares) at Dec. 31, 2022	113,056	113,056
Beginning Balance at Dec. 31, 2022	$ 270,866	$ 1,131	1,017,837	(1,351)	(746,751)
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Exercise of stock options (in shares)	289	289
Exercise of stock options	$ 2,421	$ 3	2,418
Vesting of restricted stock units (in shares)		2,541
Vesting of restricted stock units	0	$ 25	(25)
Vesting of performance stock units (in shares)		78
Vesting of performance stock units	0	$ 1	(1)
Issuance of common stock under employee stock purchase plan (in shares)		506
Issuance of common stock under employee stock purchase plan	16,224	$ 5	16,219
Stock-based compensation	109,987		109,987
Other comprehensive income (loss)	811			811
Net loss	$ (56,636)				(56,636)
Ending Balance (in shares) at Sep. 30, 2023	116,470	116,470
Ending Balance at Sep. 30, 2023	$ 343,673	$ 1,165	1,146,435	(540)	(803,387)
Beginning Balance (in shares) at Jun. 30, 2023		115,529
Beginning Balance at Jun. 30, 2023	314,561	$ 1,156	1,101,928	(701)	(787,822)
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Exercise of stock options (in shares)		123
Exercise of stock options	884	$ 1	883
Vesting of restricted stock units (in shares)		611
Vesting of restricted stock units	0	$ 6	(6)
Vesting of performance stock units (in shares)		13
Vesting of performance stock units	0
Issuance of common stock under employee stock purchase plan (in shares)		194
Issuance of common stock under employee stock purchase plan	6,310	$ 2	6,308
Stock-based compensation	37,322		37,322
Other comprehensive income (loss)	161			161
Net loss	$ (15,565)				(15,565)
Ending Balance (in shares) at Sep. 30, 2023	116,470	116,470
Ending Balance at Sep. 30, 2023	$ 343,673	$ 1,165	$ 1,146,435	$ (540)	$ (803,387)