NET REVENUES FROM COLLABORATIONS - Schedule of Deferred Revenue (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Apr. 30, 2019	Mar. 31, 2023	Dec. 31, 2022
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue		$ 35,794	$ 42,105
Global Strategic Collaboration | Regeneron Pharmaceuticals
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transaction Price Allocated	$ 521,600	559,580
Deferred revenue		220,100	226,800
Research Services Obligation | Global Strategic Collaboration | Regeneron Pharmaceuticals
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transaction Price Allocated	183,100	215,680
Deferred revenue		23,000	26,200
C5 License Obligation | Global Strategic Collaboration | Regeneron Pharmaceuticals
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transaction Price Allocated	92,500	97,900
Deferred revenue		6,000	7,000
C5 Co-Co Obligation | Global Strategic Collaboration | Regeneron Pharmaceuticals
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Transaction Price Allocated	$ 246,000	246,000
Deferred revenue		$ 191,100	$ 193,600