Pension - Schedule of Change in Projected Benefit Obligations (Detail) - Pension Benefits - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Change in Projected Benefit Obligations
Projected benefit obligations at beginning of year	$ 258.5	$ 258.7
Service cost	0.4	0.4	$ 0.7
Interest cost	5.2	12.8	13.6
Actuarial loss	(2.0)	5.4
Settlements	(238.5)	(0.6)
Benefits paid	(16.9)	(17.4)
Other	0.9	(0.8)
Projected benefit obligations at end of year	$ 7.6	$ 258.5	$ 258.7