Components of Comprehensive Income, Net of Related Tax (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Statement of Comprehensive Income [Abstract]
Net income	$ 505.1	$ 1,195.3
Other comprehensive (loss) income (OCI):
Unrealized (losses) gains on derivative contracts	(21.9)	12.1
Tax effect	6.5	(3.7)
Net current period OCI, unrealized (losses) gains on derivative contracts	(15.4)	8.4
Unrealized gains (losses) on marketable debt securities	15.7	(2.5)
Tax effect	(4.4)	0.6
Net current period OCI, unrealized gains (losses) on marketable debt securities	11.3	(1.9)
Pension plans	0.4	7.9
Tax effect		(2.2)
Net current period OCI, pension plans	0.4	5.7
Foreign currency translation gains (losses)	153.9	(118.5)
Net other comprehensive income (loss)	150.2	(106.3)
Comprehensive income	$ 655.3	$ 1,089.0