Financial Instruments - Summary of financial assets with maturities of less than 90 days included within cash and cash equivalents (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Net Investment Income [Line Items]
Cash equivalents, at carrying value	$ 2,512.8	$ 2,233.2
Money market funds
Net Investment Income [Line Items]
Cash equivalents, at carrying value	1,949.4	2,027.7
Overnight reverse repurchase agreements
Net Investment Income [Line Items]
Cash equivalents, at carrying value	34.3	70.0
Short-term debt securities
Net Investment Income [Line Items]
Cash equivalents, at carrying value	391.8	15.4
Commercial Paper
Net Investment Income [Line Items]
Cash equivalents, at carrying value	$ 137.3	$ 120.1