Benefit Plans - Obligations and Funded Status (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Change in benefit obligations
Service cost	$ 2.4	$ 2.8	$ 3.3
Interest cost	2.5	2.0	2.9
Change in plan assets
Fair value of plan assets beginning of year	34.4
Fair value of plan assets end of year	28.4	34.4
Pension plans
Change in benefit obligations
Benefit obligation beginning of year	116.1	120.8
Service cost	2.4	2.8
Interest cost	2.5	2.0
Actuarial loss	(22.6)	(2.1)
Translation (gain) loss	(0.2)	(0.6)
Benefits paid	7.7	6.8
Benefit obligation end of year	90.5	116.1	120.8
Change in plan assets
Fair value of plan assets beginning of year	34.4	33.7
Actual return on plan assets	(5.8)	(0.3)
Company contributions	7.5	8.1
Translation gain (loss)	0.0	(0.3)
Benefits paid	7.7	6.8
Fair value of plan assets end of year	28.4	34.4	33.7
Funded status
Plan assets less than benefit obligation	(62.1)	(81.7)
Other post-retirement plans
Change in benefit obligations
Benefit obligation beginning of year	11.3	13.8
Service cost	0.0	0.0
Interest cost	0.3	0.2
Actuarial loss	(1.3)	(1.4)
Translation (gain) loss	0.0	0.0
Benefits paid	1.3	1.3
Benefit obligation end of year	9.0	11.3	13.8
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	1.3	1.3
Translation gain (loss)	0.0	0.0
Benefits paid	1.3	1.3
Fair value of plan assets end of year	0.0	0.0	$ 0.0
Funded status
Plan assets less than benefit obligation	$ (9.0)	$ (11.3)