Derivative Instruments and Hedging Activities - Gross Unrealized Losses from Derivative Instruments (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	$ (29.9)	$ 23.3	$ 6.9	$ (43.7)
Amount of Gain / (Loss) Reclassified from AOCI	9.4	10.5	25.4	46.8
Cash Flow Hedges [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain / (Loss) Recognized in AOCI	(29.9)	23.3	6.9	(43.7)
Amount of Gain / (Loss) Reclassified from AOCI	9.4	10.5	25.4	46.8
Cash Flow Hedges [Member] | Foreign Exchange Forward Contracts [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain / (Loss) Recognized in AOCI	(29.9)	23.3	6.9	(43.7)
Amount of Gain / (Loss) Reclassified from AOCI	9.6	10.7	26.0	47.4
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)