Derivative Instruments and Hedging Activities - Net Investment Hedge Gains (Losses) Recognized on Condensed Consolidated Statements of Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI	$ 32.4	$ (4.3)	$ 108.4	$ (291.3)
Euro Notes [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI	12.8	(2.7)	65.9	(237.3)
Swiss Notes [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI	25.0	(10.5)	38.6	(10.5)
Cross-currency Interest Rate Swaps [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI	$ (5.4)	$ 8.9	$ 3.9	$ (43.5)