Derivative Instruments and Hedging Activities - Gross Unrealized Losses from Derivative Instruments (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Derivative Instruments Gain Loss [Line Items]
Amount of Gain / (Loss) Recognized in AOCI	$ (34.2)	$ 44.1	$ (67.0)	$ 87.5
Cash Flow Hedges [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain / (Loss) Recognized in AOCI	(34.2)	44.1	(67.0)	87.5
Amount of Gain / (Loss) Reclassified from AOCI	15.5	21.5	36.3	43.3
Cash Flow Hedges [Member] | Foreign Exchange Forward Contracts [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain / (Loss) Recognized in AOCI	(34.2)	44.1	(67.0)	87.5
Amount of Gain / (Loss) Reclassified from AOCI	15.7	21.7	36.7	43.7
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)	$ (0.4)	$ (0.4)