Dispositions - Narrative (Details) $ in Millions	1 Months Ended				12 Months Ended
	Oct. 31, 2025 USD ($)	Mar. 31, 2025 USD ($)	Apr. 30, 2024 USD ($)	Apr. 30, 2022 USD ($)	Dec. 31, 2025 USD ($) payment	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Apr. 30, 2023 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of intangible assets	$ 28.0	$ 51.0	$ 103.0
Gain on sale of priority review voucher, net					$ 0.0	$ 88.6	$ 0.0
Ionis Pharmaceuticals Inc.
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds paid to collaborative arrangement counterparty			14.4
Samsung Bioepis
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestiture of interest in joint venture				$ 1,000.0
Due from joint venture				$ 1,300.0
Number of payments | payment					2
Samsung Bioepis | Payment Due At First Anniversary
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Due from joint venture								$ 812.5
Gain (loss) on sale							13.7
Samsung Bioepis | Payment Due At Second Anniversary
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Due from joint venture			$ 437.5
Gain (loss) on sale						$ 7.5	$ 24.6
Samsung Bioepis
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage				49.90%
Amount sold				$ 2,300.0