Defined Benefit Pension Plans - Components of Net Periodic Defined Benefit Pension Benefit Cost (Detail) - Defined Benefit Pension Plans - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2.8	$ 3.7	$ 8.7	$ 11.1
Interest cost	3.0	2.5	9.2	7.3
Expected return on plan assets	(3.5)	(3.3)	(10.4)	(10.1)
Amortization of prior service cost				0.1
Recognized actuarial losses	3.6	5.3	11.1	16.3
Total	$ 5.9	$ 8.2	$ 18.6	$ 24.7