Defined contribution and defined benefit retirement plans - Schedule of Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Amounts recognized in the Consolidated Balance Sheets:
Noncurrent pension asset	$ 19.8	$ 8.1
Noncurrent accrued pension costs	(117.6)	(151.6)
Pension plans defined benefit
Change in plan assets:
Fair value at beginning of year	462.9
Fair value at end of year	480.6	462.9
Pension plans defined benefit | United States
Change in projected benefit obligations ("PBO"):
Balance at beginning of the year	42.7	43.4
Interest cost	2.7	2.2	$ 1.4
Actuarial (gains) losses	(3.1)	1.2
Benefits paid	(4.6)	(4.1)
Acquisition	27.5
Balance at end of the year	65.2	42.7	43.4
Change in plan assets:
Fair value at beginning of year	40.3	39.1
Actual return on plan assets	0.4	3.7
Employer contributions	1.5	1.6
Benefits paid	(4.6)	(4.1)
Acquisition	38.1
Fair value at end of year	75.7	40.3	39.1
Funded status	10.5	(2.4)
Amounts recognized in the Consolidated Balance Sheets:
Noncurrent pension asset	10.7
Current	(0.1)
Noncurrent accrued pension costs	(0.1)	(2.4)
Total	10.5	(2.4)
Accumulated other comprehensive loss:
Actuarial losses	28.5	30.3
Total	39.0	27.9
Accumulated benefit obligations ("ABO")	$ 65.2	$ 42.7
Defined Benefit Plan, Funding Status [Extensible List]	us-gaap:FundedPlanMember	us-gaap:FundedPlanMember
Pension plans defined benefit | Non U.S.
Change in projected benefit obligations ("PBO"):
Balance at beginning of the year	$ 563.7	$ 508.6
Service cost	6.6	6.3	11.3
Interest cost	18.9	19.8	10.6
Participants' contributions	1.8	1.8
Actuarial (gains) losses	(16.2)	44.3
Settlements	(1.9)	(8.6)
Change in currency exchange rates	(36.8)	14.1
Benefits paid	(22.8)	(22.6)
Balance at end of the year	513.3	563.7	508.6
Change in plan assets:
Fair value at beginning of year	422.6	390.5
Actual return on plan assets	20.0	37.4
Employer contributions	14.9	14.7
Participants' contributions	1.8	1.8
Settlements	(1.9)	(8.6)
Change in currency exchange rates	(29.7)	9.4
Benefits paid	(22.8)	(22.6)
Fair value at end of year	404.9	422.6	$ 390.5
Funded status	(108.4)	(141.1)
Amounts recognized in the Consolidated Balance Sheets:
Noncurrent pension asset	9.1	8.1
Noncurrent accrued pension costs	(117.5)	(149.2)
Total	(108.4)	(141.1)
Accumulated other comprehensive loss:
Actuarial losses	88.8	106.8
Prior service cost	0.3	0.3
Total	89.1	107.1
Total	(19.3)	(34.0)
Accumulated benefit obligations ("ABO")	$ 499.7	$ 549.8
Defined Benefit Plan, Funding Status [Extensible List]	us-gaap:FundedPlanMember	us-gaap:FundedPlanMember