Intangible Assets - Schedule of Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets, net	$ 1,038.6	$ 915.5
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount	1,171.6	956.3
Accumulated Amortization	(133.0)	(40.8)
Acquired in-process research and development
Indefinite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	$ 42.5	0.0
Acquired product rights - Libtayo
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life (in years)	13 years
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount	$ 1,119.1	946.3
Accumulated Amortization	(126.7)	(35.7)
Net Carrying Amount	$ 992.4	910.6
Other intangibles
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life (in years)	8 years
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount	$ 10.0	10.0
Accumulated Amortization	(6.3)	(5.1)
Net Carrying Amount	$ 3.7	$ 4.9