Defined Benefit Pension Plans - Components of Net Periodic Defined Benefit Pension Benefit Cost (Detail) - Defined Benefit Pension Plans - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3.0	$ 3.8
Interest cost	3.2	2.4
Expected return on plan assets	(3.5)	(3.4)
Recognized actuarial losses	3.8	5.4
Total	$ 6.5	$ 8.2