Employee Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - Defined Benefit Pension Plans - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3.8	$ 3.2
Interest cost	2.2	2.6
Expected return on plan assets	(3.0)	(2.3)
Recognized actuarial losses	5.1	4.4
Total	$ 8.1	$ 7.9