Balance Sheet Components (Prepaids and other current assets) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Schedule of Other Assets [Line Items]
Prepaid expenses	$ 155.9	$ 194.6
Available-for-sale fixed income securities	37.0	35.3
Fair value of financial instruments	106.2	134.7
Equity securities	49.3	42.6
Deferred charge for taxes on intercompany profit	747.3	747.2
Income tax receivable	340.2	328.4
Other current assets	271.0	328.4
Prepaid expenses and other current assets	2,028.1	1,811.2
Biocon Biologics
Schedule of Other Assets [Line Items]
Deferred consideration due from Biocon Biologics	0.0	299.5
Other Current Assets | Biocon Biologics
Schedule of Other Assets [Line Items]
Deferred consideration due from Biocon Biologics	$ 321.2	$ 0.0