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NET REVENUES FROM COLLABORATIONS - Schedule of Revenue Recognized by Accounting Guidance (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Apr. 30, 2019
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue Recognized	$ 494,333	$ 319,290
Roche \| Roche Collaboration and License Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transactional price remaining performance obligation	922,000
Revenue Recognized	72,151	0
Roche \| Roche License Obligation \| Roche Collaboration and License Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transactional price remaining performance obligation	375,000
Revenue Recognized	65,000	0
Roche \| Roche Development Services Obligation \| Roche Collaboration and License Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transactional price remaining performance obligation	545,000
Revenue Recognized	7,151	0
Roche \| Roche Technology Transfer Obligation \| Roche Collaboration and License Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transactional price remaining performance obligation	2,000
Revenue Recognized	0	0
Regeneron Pharmaceuticals \| Global Strategic Collaboration
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transactional price remaining performance obligation	676,280		$ 521,600
Revenue Recognized	17,100	15,400
Regeneron Pharmaceuticals \| Research Services Obligation \| Global Strategic Collaboration
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transactional price remaining performance obligation	305,680		183,100
Revenue Recognized	14,700	10,700
Regeneron Pharmaceuticals \| C5 License Obligation \| Global Strategic Collaboration
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transactional price remaining performance obligation	124,600		92,500
Revenue Recognized	1,700	2,200
Regeneron Pharmaceuticals \| C5 Co-Co Obligation \| Global Strategic Collaboration
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transactional price remaining performance obligation	246,000		$ 246,000
Revenue Recognized	$ 700	$ 2,500