v3.25.4

NET REVENUES FROM COLLABORATIONS - Additional Information (Detail) $ in Thousands		1 Months Ended		12 Months Ended
	Jul. 21, 2023 performance_obligation	Mar. 31, 2025 USD ($)	Jun. 30, 2024 USD ($) performance_obligation	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2019 USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Contract with customer liability revenue recognized				$ 53,800	$ 266,500
Total revenues				3,713,937	2,248,243	$ 1,828,292
Research and development				1,319,775	1,126,232	1,004,415
Collaborations
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenues				553,366	510,221	546,185
Roche | License
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transaction price				1,740,000
Increase in transaction price				423,600
Developmental milestone increase in transaction price				300,000
Total revenues				300,000
Vir Biotechnology, Inc. | Collaborations
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenues		$ 30,000		$ 30,000
Roche Collaboration and License Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development costs, percentage responsible	40.00%
Profit and loss sharing percentage	50.00%
Number of performance obligations | performance_obligation	3
Roche Collaboration and License Agreement | Roche
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development costs, percentage responsible	60.00%
Profit and loss sharing percentage	50.00%
Actual reimbursement of transactional price (as percent)				60.00%
Transaction price				$ 1,738,167
Total revenues				394,881	119,489	337,802
Transactional price remaining performance obligation				904,400
Research and development				160,000	92,700	44,600
Global Strategic Collaboration | Regeneron Pharmaceuticals
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of performance obligations | performance_obligation			2
Total revenues				113,957	302,798	100,468
Transactional price remaining performance obligation				34,100
Research and development				62,000	71,700	77,400
Upfront payment			$ 10,000
Maximum royalties and commercial milestone payments upon potential product sale			325,000
Maximum additional milestone payments to be receive upon achievement of certain criteria							$ 100,000
Maximum percentage of royalty payments							20.00%
Global Strategic Collaboration | Regeneron Pharmaceuticals | Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement milestone payments, per collaboration project							$ 150,000
Royalty rate							20.00%
Global Strategic Collaboration | Regeneron Pharmaceuticals | Funding At Program Initiation
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential proceeds from collaboration arrangement							$ 2,500
Global Strategic Collaboration | Regeneron Pharmaceuticals | Funding At Lead Candidate Identification
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential proceeds from collaboration arrangement							$ 2,500
Global Strategic Collaboration | Regeneron Pharmaceuticals | Research Services Obligation
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transaction price				100,500
Total revenues				39,519	39,097	80,200
Global Strategic Collaboration | Regeneron Pharmaceuticals | C5 Monotherapy Obligation
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total revenues				$ 0	$ 191,520	$ 0
Fixed consideration			$ 191,500
Product Alliances | 2013 The Medicines Company Collaboration | Maximum | Novartis AG
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalty rate				20.00%
Product Alliances | 2013 The Medicines Company Collaboration | Minimum | Novartis AG
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalty rate				10.00%

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