Balance Sheet Components (Prepaid Expenses and Other Current Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Prepaid expenses	$ 134.5	$ 155.9
Fair value of financial instruments	73.7	106.2
Equity securities	55.6	49.3
Other current assets	335.2	271.0
Prepaid expenses and other current assets	1,627.0	2,028.1
Deferred Charges, Tax On Intercompany Profit	602.5	747.3
Income Taxes Receivable	227.5	340.2
Other Current Assets | Biocon Biologics
Property, Plant and Equipment [Line Items]
Disposal Group, Including Discontinued Operation, Deferred Consideration Due	158.3	321.2
Available-for-sale fixed income investments
Property, Plant and Equipment [Line Items]
Available-for-sale securities	$ 39.7	$ 37.0