Collaborations - Additional Information (Details)						3 Months Ended		6 Months Ended		12 Months Ended
	Aug. 20, 2020	Jul. 07, 2020 USD ($)	May 09, 2019 USD ($) $ / shares shares	Nov. 01, 2018	Oct. 31, 2017 shares	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($) shares	Dec. 31, 2020 USD ($) shares
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development						$ 35,220,000	$ 13,819,000	$ 61,181,000	$ 25,935,000
Revenue recognized						18,519,000	3,288,000	37,221,000	6,716,000
Stock split, conversion ratio	1.5949
Sanofi Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment		$ 150,000,000.0
Collaboration agreement transaction price		150,000,000.0
Revenue recognized recorded in deferred revenue						14,400,000		26,000,000.0
Unsatisfied performance obligation						108,400,000		108,400,000		$ 132,600,000
Cost reimbursement payment received								1,700,000
Milestone receivable						0		0
Royalty receivable						0		0
Unbilled accounts receivable						900,000		$ 900,000
Research and development						0
Remaining research term of collaboration								2 years 8 months 12 days
Sanofi Agreement | Collaboration Target 1
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration agreement transaction price		120,000,000.0
Revenue recognized recorded in deferred revenue						12,000,000.0		$ 21,500,000
Sanofi Agreement | Collaboration Target 2
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration agreement transaction price		30,000,000.0
Revenue recognized recorded in deferred revenue						2,400,000		4,500,000
Sanofi Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Development milestone payments		1,480,000,000
Commercial Milestone Payments		700,000,000.0
Sanofi Agreement | Minimum | IRAK4 Program
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Development milestone payments		1,000,000,000.0
Commercial Milestone Payments		$ 400,000,000.0
Vertex Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized recorded in deferred revenue								11,200,000
Unsatisfied performance obligation						26,500,000		26,500,000		37,700,000
Initial research term of collaboration			4 years
Extended research term of collaboration			1 year
Revenue recognized						$ 4,100,000	$ 3,300,000	$ 11,200,000	6,700,000
Vertex Agreement | Series B-1 Preferred Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration agreement transaction price			$ 55,900,000
Non refundable upfront payment received			$ 50,000,000.0
Number of shares issued | shares			3,059,695
Stock issued price per share | $ / shares			$ 6.54
Preferred stock premium			$ 5,900,000
Vertex Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Eligible to receive payments including development, regulatory and commercial milestones			$ 170,000,000.0
Revenue remaining research term						1 year 3 months 18 days		1 year 3 months 18 days
Compound Collaboration
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Written notice period to terminate collaboration agreement								60 days
Compound Collaboration | Series A Preferred Units
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development									$ 200,000	$ 200,000
Number of shares issued | shares					886,305
Stock split, conversion ratio				100
Share-based compensation vesting period				3 years
Number of shares vested | shares									110,788	110,788