Schedule of Income subject to domestic and foreign taxation (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax [Abstract]
Income Before Tax, Domestic	$ 2,129.5	$ 1,506.2	$ 1,596.8
Income Before Tax, Foreign	121.8	133.9	153.2
Income Before Income Tax	2,251.3	1,640.1	1,750.0
Current Tax Expense (Benefit), Domestic	393.1	440.4	306.5
Current State and Local Tax Expense (Benefit)	(8.5)	(2.5)	12.7
Current Tax Expense (Benefit), Foreign	47.5	14.1	154.3
Income Tax (Benefit) - Current	432.1	452.0	473.5
Deferred Tax Expense (Benefit), Federal	59.8	(106.2)	42.7
Deferred State and Local Income Tax Expense (Benefit)	(0.6)	(1.5)	1.1
Deferred Tax Expense (Benefit), Foreign	(19.1)	12.0	(174.5)
Deferred Income Tax Expense (Benefit)	40.1	(95.7)	(130.7)
Income Tax Expense	$ 472.2	$ 356.3	$ 342.8