Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - Pension plans - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1.0	$ 1.1	$ 1.1
Interest cost	4.6	4.0	4.5
Expected return on plan assets	(0.1)	(0.1)	(0.1)
Net actuarial loss (gain)	(12.9)	0.6	13.9
Net periodic benefit expense (income)	$ (7.4)	$ 5.6	$ 19.4