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, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI	$ (4.3)	$ (111.2)	$ (291.3)	$ (7.0)
Euro Notes [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI	(2.7)	(44.4)	(237.3)	(11.6)
Swiss Notes [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI	(10.5)		(10.5)
Cross-currency Interest Rate Swaps [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI	$ 8.9	$ (66.8)	$ (43.5)	$ 4.6