Collaboration and License Agreements - Additional Information (Details)			1 Months Ended			12 Months Ended
	Feb. 08, 2023	Feb. 14, 2021 Program	Jul. 31, 2022 USD ($)	May 31, 2018 Program	Oct. 31, 2017 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accrued and other liabilities						$ 104,220,000	$ 489,090,000
Research and development						589,671,000	474,648,000	$ 448,006,000
Deferred revenue, current						64,853,000	15,517,000
Total revenues						86,180,000	1,615,797,000	1,095,415,000
Cost of revenue						2,765,000	146,319,000	65,865,000
Contract revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues						2,228,000	52,714,000	169,874,000
Collaboration revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues						37,266,000	1,505,469,000	917,194,000
License revenue from a related party
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues						0	22,289,000	0
2020 GSK
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payments to counterparty						341,400,000
Research and development						23,400,000	31,400,000	77,300,000
Preliminary Collaboration Agreement | 2021 GSK
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of separate programs | Program		3
2021 GSK Collaboration
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development						2,200,000	2,300,000	500,000
Percentage of share development costs		50.00%
Percentage of profits and loss		50.00%
Deferred revenue, current						51,700,000
2021 GSK Collaboration | Contract revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenues							$ 39,800,000
Brii Agreement | Development Programs Exercised by Brii | VIR-3434
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Option exercise fee received			$ 20,000,000
Brii Agreement | Brii Bio Parent
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Maximum number of development program granted from Vir to Brii | program | Program				4
Maximum number of development program granted from Brii to Vir | program | Program				4
Brii Agreement | Brii Bio Parent | VIR-3434
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price			22,300,000
Deferred revenue			$ 2,300,000
Alnylam Agreement | Alnylam Pharmaceuticals Inc
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Royalty payment obligation expiration period after first commercial sales							10 years
Written notice period for termination of licensed program					90 days
Written notice period to terminate licensed program for uncured material breach					60 days
Written notice period to terminate licensed program for payment breach					30 days
Written notice period to terminate licensed program if under challenge					30 days
Expenses incurred under agreement						1,700,000	$ 1,400,000	11,200,000
Alnylam Agreement | Alnylam Pharmaceuticals Inc | First siRNA Product HBV
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Maximum milestone payment for achievement of specified milestones					$ 190,000,000
Maximum aggregate sales milestone payment					$ 250,000,000
2020 Xencor Agreement | Xencor
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Cost of revenue						$ 2,200,000	$ 114,500,000	$ 52,700,000
2019 and 2020 Xencor Agreement member | Xencor
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Written notice period for termination of licensed program						60 days
Written notice period for uncured material breach						60 days
Written notice period to terminate licensed program for failure to make payment						30 days
Written notice period to terminate licensed program if under challenges						30 days
Amendment Number Three | 2020 GSK | Antibody Program
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of development costs	72.50%