Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Retirement Benefits [Abstract]
Service cost	$ 0.4	$ 0.4
Interest cost	1.0	1.0
Expected return on plan assets	(0.1)	(0.2)
Net periodic benefit cost	$ 1.3	$ 1.2