Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	IPO	Redeemable Convertible Preferred Stock	Redeemable Convertible Preferred Stock IPO	Common Stock	Common Stock IPO	Additional Paid-in Capital	Additional Paid-in Capital Cumulative Effect, Period of Adoption, Adjustment	Additional Paid-in Capital IPO	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income	Non-controlling Interest
Temporary equity, beginning balance (in shares) at Dec. 31, 2017				21,233,190
Temporary equity, beginning balance at Dec. 31, 2017				$ 105,235
Temporary equity, ending balance (in shares) at Dec. 31, 2018				21,233,190
Temporary equity, ending balance at Dec. 31, 2018				$ 105,235
Beginning balance (in shares) at Dec. 31, 2017						663,270
Beginning balance at Dec. 31, 2017	$ (98,578)					$ 1		$ 2,977			$ (101,556)		$ 0	$ 0
Beginning balance (Cumulative effect of change in accounting principle - ASC 606 adoption) at Dec. 31, 2017		$ 87										$ 87
Beginning balance (Cumulative effect of change in accounting treatment - ASU 2016-09) at Dec. 31, 2017		$ 0							$ 13			$ (13)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	438,578					438,578
Exercise of stock options	$ 656							656
Stock-based compensation	911							911
NeuroCo common stock issuance	1													1
Issuance of common stock in connection with NeuroCo merger (in shares)						33,462
Issuance of common stock in connection with NeuroCo merger	0
Net loss	(37,630)
Comprehensive loss	(37,630)										(37,629)			(1)
Ending balance (in shares) at Dec. 31, 2018						1,135,310
Ending balance at Dec. 31, 2018	(134,553)					$ 1		4,557			(139,111)		0	0
Increase (Decrease) in Temporary Equity [Roll Forward]
Net exercise of Series C preferred stock warrants upon IPO (in shares)				292,361	1,653,004
Net exercise of Series C preferred stock warrants upon IPO				$ 1,784	$ 37,121
Conversion of preferred stock to common stock upon IPO (in shares)					(23,178,555)
Conversion of preferred stock to common stock upon IPO					$ (144,140)
Temporary equity, ending balance (in shares) at Dec. 31, 2019				0
Temporary equity, ending balance at Dec. 31, 2019				$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise/issuance of common stock (in shares)						3,764
Exercise/issuance of common stock	$ 31							31
Exercise of stock options (in shares)	873,786					873,786	6,000,000
Exercise of stock options	$ 1,542		$ 109,119			$ 1	$ 6	1,541		$ 109,113
Conversion of preferred stock to common stock upon IPO (in shares)							23,178,555
Conversion of preferred stock to common stock upon IPO			$ 144,140				$ 23			$ 144,117
Exercise of warrants (in shares)							2,204
Issuance of common stock under employee stock purchase plan (in shares)						61,648
Issuance of common stock under employee stock purchase plan	1,048							1,048
Stock-based compensation	2,977							2,977
Net loss	(52,415)										(52,415)
Unrealized gain on investments, net	2												2
Ending balance (in shares) at Dec. 31, 2019						31,255,267
Ending balance at Dec. 31, 2019	71,891					$ 31		263,384			(191,526)		2	0
Temporary equity, ending balance (in shares) at Dec. 31, 2020				0
Temporary equity, ending balance at Dec. 31, 2020				$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise/issuance of common stock (in shares)						1,923,076
Exercise/issuance of common stock	$ 70,543					$ 2		70,541
Exercise of stock options (in shares)	1,018,779					1,018,779
Exercise of stock options	$ 3,487					$ 1		3,486
Issuance of common stock under employee stock purchase plan (in shares)						52,527
Issuance of common stock under employee stock purchase plan	1,681							1,681
Stock-based compensation	7,226							7,226
Net loss	(47,365)										(47,365)
Unrealized gain on investments, net	37												37
Ending balance (in shares) at Dec. 31, 2020						34,249,649
Ending balance at Dec. 31, 2020	$ 107,500					$ 34		$ 346,318			$ (238,891)		$ 39	$ 0