BUSINESS OVERVIEW AND SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($) therapy tranche	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Significant Accounting Policies [Line Items]
Number of commercial therapies | therapy	8
Capitalized costs, amortization expense	$ 7.4	$ 0.0	$ 0.0
Payment term after customer control	1 year
Period between customer control and payment	1 year
Advertising expenses	$ 50.5	34.5	27.8
Number of tranches in offering period | tranche	4
Span of offering period	24 months
Foreign currency transaction losses	$ 6.1	$ 8.6	$ 27.7
Minimum | ALDURAZYME
Significant Accounting Policies [Line Items]
Payment received as percentage of net product sales	39.50%
Maximum | ALDURAZYME
Significant Accounting Policies [Line Items]
Payment received as percentage of net product sales	50.00%