Retirement Plans, Postretirement and Postemployment Benefits - Schedule of Components of Net Periodic Benefit Cost (Credit) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 32.9	$ 48.1	$ 46.2
Interest cost	51.3	41.2	35.7
Expected return on assets	(71.4)	(77.3)	(70.5)
Prior service cost (credit)	5.9	4.9	0.8
Actuarial gain (loss)	0.6	3.9	12.2
Settlement charge (credit)	0.0	4.6	0.0
Total net periodic benefit cost (credit)	19.3	25.4	24.4
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost	0.5	0.4	0.3
Prior service cost (credit)	(0.3)	(0.9)	(0.8)
Actuarial gain (loss)	(0.6)	(0.2)	(0.1)
Total net periodic benefit cost (credit)	$ (0.4)	$ (0.7)	$ (0.6)