Derivative Instruments and Hedging Activities - Gross Unrealized Losses from Derivative Instruments (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	$ 23.3	$ (54.0)	$ (43.7)	$ 33.5
Amount of Gain / (Loss) Reclassified from AOCI	10.5	20.8	46.8	64.1
Cash Flow Hedges [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain / (Loss) Recognized in AOCI	23.3	(54.0)	(43.7)	33.5
Amount of Gain / (Loss) Reclassified from AOCI	10.5	20.8	46.8	64.1
Cash Flow Hedges [Member] | Foreign Exchange Forward Contracts [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain / (Loss) Recognized in AOCI	23.3	(54.0)	(43.7)	33.5
Amount of Gain / (Loss) Reclassified from AOCI	10.7	21.0	47.4	64.7
Cash Flow Hedges [Member] | Forward Starting Interest Rate Swaps [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain / (Loss) Reclassified from AOCI	$ (0.2)	$ (0.2)	$ (0.6)	$ (0.6)