Balance Sheet Components (Prepaid Expenses and Other Current Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Prepaid expenses	$ 178.9	$ 155.9
Fair value of financial instruments	73.3	106.2
Equity securities	52.1	49.3
Other current assets	249.5	271.0
Prepaid expenses and other current assets	1,933.3	2,028.1
Deferred Charges, Tax On Intercompany Profit	701.8	747.3
Income Taxes Receivable	310.7	340.2
Other Current Assets | Biocon Biologics
Property, Plant and Equipment [Line Items]
Disposal Group, Including Discontinued Operation, Deferred Consideration Due	328.3	321.2
Available-for-sale fixed income investments
Property, Plant and Equipment [Line Items]
Available-for-sale securities	$ 38.7	$ 37.0