Collaboration, License and Research Agreements - Additional Information (Details)	1 Months Ended	3 Months Ended		6 Months Ended
	Apr. 30, 2019 USD ($) Product	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) Obligation	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized		$ 2,178,000	$ 2,607,000	$ 3,973,000	$ 5,311,000
Research Collaboration and License Agreement with Eli Lilly
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront fees received	$ 20,000,000.0
License agreement expiry period	10 years
Number of performance obligation | Obligation				1
Period for expects performance obligation				5 years
Revenue recognized		2,100,000	2,500,000	$ 3,800,000	5,100,000
Deferred revenue		9,233,000		9,233,000		$ 11,108,000
Research Collaboration and License Agreement with Eli Lilly | Prepaid and Other Assets
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration receivables		1,100,000		1,100,000		$ 900,000
Research Collaboration and License Agreement with Eli Lilly | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Rights to antibody oligonucleotide conjugates for messengers RNA targets. | Product	6
Development milestone payment eligible to receive per target	$ 60,000,000.0
Regulatory milestone payment eligible to receive per target	140,000,000.0
Commercialization milestone payment eligible to receive	$ 205,000,000.0
Research Collaboration with MyoKardia, Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized		$ 40,500	$ 100,000	$ 100,000	$ 200,000