Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Retirement Benefits [Abstract]
Service cost	$ 0.3	$ 0.4
Interest cost	1.0	1.0
Expected return on plan assets	(0.2)	(0.1)
Net periodic benefit cost	$ 1.1	$ 1.3