Collaborative and Other Relationships - Summary of Activity Related to the UCB Collaboration (Details) - Research and Development Expense [Member] - UCB Pharma S.A. - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Collaborative arrangements and non-collaborative arrangement transactions
Expense incurred by the collaboration	$ 29.4	$ 21.8
Expense reflected within statements of income	$ 14.7	$ 10.9

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 808
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479402/808-10-50-1

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