Intangible Assets and Goodwill - Summary of Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Finite-Lived Intangible Assets, Net [Abstract]
Finite-Lived Intangible Assets, Gross	$ 14,028.8	$ 11,728.8
Accumulated Amortization	(5,948.1)	(5,869.8)
Net	8,080.7	5,859.0
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Cost	14,232.8	14,232.8
Accumulated Amortization	5,948.1	5,869.8
Net	8,284.7	8,363.0
In-process research and development
Indefinite-Lived Intangible Assets [Line Items]
Cost and net	40.0	2,340.0
Priority review voucher
Indefinite-Lived Intangible Assets [Line Items]
Cost and net	100.0	100.0
Trademarks and trade names
Indefinite-Lived Intangible Assets [Line Items]
Cost and net	64.0	64.0
Acquired and in-licensed rights and patents
Finite-Lived Intangible Assets, Net [Abstract]
Finite-Lived Intangible Assets, Gross	10,480.2	8,180.2
Accumulated Amortization	(2,514.0)	(2,440.7)
Net	7,966.2	5,739.5
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	$ 2,514.0	2,440.7
Acquired and in-licensed rights and patents | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated life (in years)	2 years
Acquired and in-licensed rights and patents | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated life (in years)	22 years
Developed technology and other
Finite-Lived Intangible Assets, Net [Abstract]
Finite-Lived Intangible Assets, Gross	$ 3,548.6	3,548.6
Accumulated Amortization	(3,434.1)	(3,429.1)
Net	114.5	119.5
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	$ 3,434.1	$ 3,429.1
Developed technology and other | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated life (in years)	13 years
Developed technology and other | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated life (in years)	31 years