Benefit Plans - Obligations and funded status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Change in plan assets
Company contributions	$ 5.4	$ 4.7
Pension plans
Change in benefit obligations
Benefit obligation beginning of year	120.3	125.9
Service cost	1.0	1.1	$ 1.1
Interest cost	4.6	4.0	4.5
Actuarial (gain) loss	(12.8)	0.6
Foreign currency translation	15.0	(7.5)
Benefits paid	(5.4)	(3.8)
Benefit obligation end of year	122.7	120.3	125.9
Change in plan assets
Fair value of plan assets beginning of year	3.1	3.2
Actual return on plan assets	0.2	0.0
Company contributions	4.7	3.9
Foreign currency translation	0.4	(0.2)
Benefits paid	(5.4)	(3.8)
Fair value of plan assets end of year	3.0	3.1	3.2
Funded status
Fair value of plan assets end of year	3.0	3.1	3.2
Benefit obligation end of year	122.7	120.3	125.9
Benefit obligations in excess of the fair value of plan assets	(119.7)	(117.2)
Post-retirement
Change in benefit obligations
Benefit obligation beginning of year	11.4	12.5
Service cost	0.0	0.1
Interest cost	0.6	0.6
Actuarial (gain) loss	(0.2)	(1.0)
Foreign currency translation	0.0	0.0
Benefits paid	(0.7)	(0.8)
Benefit obligation end of year	11.1	11.4	12.5
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	0.7	0.8
Foreign currency translation	0.0	0.0
Benefits paid	(0.7)	(0.8)
Fair value of plan assets end of year	0.0	0.0	0.0
Funded status
Fair value of plan assets end of year	0.0	0.0	0.0
Benefit obligation end of year	11.1	11.4	$ 12.5
Benefit obligations in excess of the fair value of plan assets	$ (11.1)	$ (11.4)