NET REVENUES FROM COLLABORATIONS - Regeneron Pharmaceuticals (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2019 USD ($) program
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 102,753	$ 42,105
Total revenues	1,828,292	1,037,418	$ 844,287
Global Strategic Collaboration | Regeneron Pharmaceuticals
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Discovery period of programs development				5 years
Extended additional discovery period of programs development				5 years
Maximum royalties and commercial milestone payments upon potential product sale				$ 325,000
Upfront fee received				400,000
Maximum additional milestone payments to be receive upon achievement of certain criteria				$ 100,000
Number of targeted programs | program				30
Direction period of programs development				5 years
Collaborative agreement termination notice period				90 days
Percentage of maximum royalty payments				20.00%
Transaction Price Allocated	675,800			$ 521,600
Increase (decrease) in transaction price	116,900
Deferred revenue	277,100	226,800
Total revenues	72,500	81,180	101,100
Transactional price remaining performance obligation	334,700
Global Strategic Collaboration | Regeneron Pharmaceuticals | Milestone
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone received	100,000
Global Strategic Collaboration | Regeneron Pharmaceuticals | Research Services Obligation
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Standalone Selling Price				130,700
Transaction Price Allocated	305,700			183,100
Deferred revenue	63,400	26,200
Total revenues	80,200	28,600	37,600
Global Strategic Collaboration | Regeneron Pharmaceuticals | C5 License Obligation
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Standalone Selling Price				97,600
Transaction Price Allocated	124,100			92,500
Deferred revenue	27,500	7,000
Total revenues	(15,100)	32,500	44,600
Global Strategic Collaboration | Regeneron Pharmaceuticals | C5 Co-Co Obligation
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Standalone Selling Price				364,600
Transaction Price Allocated	246,000			246,000
Deferred revenue	186,200	193,600
Total revenues	$ 7,400	$ 20,080	$ 18,900
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 | Funding An Annual Discovery
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential proceeds from collaboration arrangement				30,000
Global Strategic Collaboration | Regeneron Pharmaceuticals | Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research term extension fee				300,000
Collaborative arrangement milestone payments				$ 150,000
Royalty rate				20.00%