Income Taxes - Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Amount
Statutory rate	$ 326,900
State and local income taxes, net of federal income tax effect	8,500
Foreign tax effects:
Withholding tax	(20,400)
Cantonal tax impact	11,900
Pillar Two taxes	(17,200)
Changes in valuation allowances	(190,200)
Taxable intercompany dividend	22,800
Litigation matter	21,000
Effects of changes in tax laws or rates	(11,500)
Effects of cross-border tax laws
GILTI, net of foreign tax credits	88,000
Other, net of foreign tax credits	18,500
Tax Credits
Orphan drug credits	(31,300)
Other credits	(4,500)
Nontaxable or nondeductible items
Equity compensation	18,900
Other permanent differences	16,900
Changes in unrecognized tax benefits	9,600
Total income tax (benefit) expense	$ 263,600	$ 273,800	$ 135,300
Rate
Statutory rate	21.00%	21.00%	21.00%
State and local income taxes, net of federal income tax effect	0.50%	1.80%	1.10%
Foreign tax effects:
Withholding tax	(1.30%)
Statutory tax rate difference		(7.60%)	(5.90%)
Cantonal tax impact	0.80%
Pillar Two taxes	(1.10%)
Changes in valuation allowances	(12.20%)
Taxable intercompany dividend	1.50%
Litigation matter	1.30%
Other		0.90%	1.50%
Effects of changes in tax laws or rates	(0.70%)
Effects of cross-border tax laws
GILTI, net of foreign tax credits	5.70%	(1.60%)	(0.60%)
Other, net of foreign tax credits	1.20%
Tax Credits
Orphan drug credits	(2.00%)
Other credits	(0.30%)
Nontaxable or nondeductible items
Equity compensation	1.20%
Other permanent differences	1.10%
Changes in unrecognized tax benefits	0.60%
Tax credits		(2.20%)	(7.30%)
Purchased inventory valuation step-up and intangible assets		2.10%	0.70%
Internal reorganization		0.00%	(0.10%)
Income tax expense and effective tax rate	16.90%	14.40%	10.40%
Italy
Foreign tax effects:
Other	$ 1,800
Foreign tax effects:
Other	0.10%
Switzerland
Foreign tax effects:
Statutory tax rate difference	$ (22,100)
Other	$ (6,100)
Foreign tax effects:
Statutory tax rate difference	(1.40%)
Other	(0.40%)
U.K.
Foreign tax effects:
Other	$ 700
Foreign tax effects:
Other	0.00%
Other foreign jurisdictions
Foreign tax effects:
Statutory tax rate difference	$ 9,500
Foreign tax effects:
Statutory tax rate difference	0.60%
United States
Foreign tax effects:
Other	$ 11,900
Foreign tax effects:
Other	0.70%