Benefit Plans - Obligations and Funded Status (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Change in benefit obligations
Service cost	$ 1.7	$ 1.7	$ 2.4
Interest cost	3.9	4.1	2.5
Change in plan assets
Fair value of plan assets beginning of year	30.5
Fair value of plan assets end of year	27.4	30.5
Pension plans
Change in benefit obligations
Benefit obligation beginning of year	97.5	90.5
Service cost	1.7	1.7
Interest cost	3.9	4.1
Actuarial loss	(2.7)	7.4
Translation (gain) loss	(1.1)	1.1
Benefits paid	(7.2)	(7.3)
Benefit obligation end of year	83.3	97.5	90.5
Change in plan assets
Fair value of plan assets beginning of year	30.5	28.4
Actual return on plan assets	0.6	0.8
Company contributions	11.2	7.6
Defined Benefit Plan, Plan Assets, Payment for Settlement	(6.8)	0.0
Translation gain (loss)	(0.9)	1.0
Benefits paid	(7.2)	(7.3)
Fair value of plan assets end of year	27.4	30.5	28.4
Funded status
Plan assets less than benefit obligation	(55.9)	(67.0)
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment	(2.0)	0.0
Lump-sum payments	(6.8)	0.0
Other post-retirement plans
Change in benefit obligations
Benefit obligation beginning of year	7.6	9.0
Service cost	0.0	0.0
Interest cost	0.4	0.5
Actuarial loss	(0.6)	(0.8)
Translation (gain) loss	0.0	0.0
Benefits paid	(0.8)	(1.1)
Benefit obligation end of year	6.6	7.6	9.0
Change in plan assets
Fair value of plan assets beginning of year	0.0	0.0
Actual return on plan assets	0.0	0.0
Company contributions	0.8	1.1
Defined Benefit Plan, Plan Assets, Payment for Settlement	0.0	0.0
Translation gain (loss)	0.0	0.0
Benefits paid	(0.8)	(1.1)
Fair value of plan assets end of year	0.0	0.0	$ 0.0
Funded status
Plan assets less than benefit obligation	(6.6)	(7.6)
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment	0.0	0.0
Lump-sum payments	$ 0.0	$ 0.0