Pensions and Post-Retirement Benefit Plans - Components of Net Periodic Benefit Cost for Pension Plans (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Postemployment Benefits [Abstract]
Service cost	$ 0.4	$ 0.3
Interest cost	2.1	1.4
Expected return on plan assets	(1.7)	(2.0)
Amortization of net loss	0.5	0.5
Net periodic benefit cost	1.3	0.2
Defined contribution plan expense	$ 2.5	$ 2.5