SEGMENT INFORMATION - Schedule of Total Revenues and Disaggregates Net Product Revenues by Product (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]
Total revenues	$ 989,708	$ 825,410	$ 1,755,916	$ 1,570,555
Net product revenues
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]
Total revenues	984,393	812,982	1,744,471	1,547,626
VOXZOGO
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]
Total revenues	252,528	221,391	472,408	435,145
VIMIZIM
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]
Total revenues	194,371	215,424	404,575	403,770
NAGLAZYME
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]
Total revenues	135,255	128,867	265,329	243,157
PALYNZIQ
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]
Total revenues	135,167	105,938	224,725	199,207
GALAFOLD
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]
Total revenues	105,748	0	105,748	0
BRINEURA
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]
Total revenues	51,370	48,692	98,474	89,054
ALDURAZYME
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]
Total revenues	43,539	56,437	80,281	105,414
POMBILITI + OPFOLDA
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]
Total revenues	30,258	0	30,258	0
KUVAN
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]
Total revenues	24,444	27,034	48,324	52,170
ROCTAVIAN
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]
Total revenues	11,713	9,199	14,349	19,709
Royalty and other revenues
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]
Total revenues	$ 5,315	$ 12,428	$ 11,445	$ 22,929