Defined contribution and defined benefit retirement plans - Schedule of Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 16, 2025
Amounts recognized in the Consolidated Balance Sheets:
Noncurrent pension asset	$ 20.4	$ 19.8
Noncurrent accrued pension costs	(80.9)	(117.6)
Pension Plans
Change in plan assets:
Fair value at beginning of the year	480.6
Fair value at end of the year	464.9	480.6
Pension Plans | UNITED STATES
Change in projected benefit obligations ("PBO"):
Balance at beginning of the year	65.2	42.7
Interest cost	3.4	2.7	$ 2.2
Actuarial (gains) losses	2.4	(3.1)
Settlements	(65.6)
Benefits paid	(5.3)	(4.6)
Acquisition		27.5
Balance at end of the year	0.1	65.2	42.7
Change in plan assets:
Fair value at beginning of the year	75.7	40.3
Actual return on plan assets	3.3	0.4
Employer contributions		1.5
Settlements	(64.7)
Benefits paid	(5.3)	(4.6)
Acquisition		38.1
Fair value at end of the year	9.0	75.7	40.3
Funded status	8.9	10.5		$ 9.0
Amounts recognized in the Consolidated Balance Sheets:
Noncurrent pension asset	9.0	10.7
Current	(0.1)	(0.1)
Noncurrent accrued pension costs		(0.1)
Total	8.9	10.5
Accumulated other comprehensive loss:
Actuarial losses		28.5
Total	8.9	39.0
Accumulated benefit obligations ("ABO")	$ 0.1	$ 65.2
Defined Benefit Plan, Funding Status [Extensible List]	us-gaap:FundedPlanMember	us-gaap:FundedPlanMember
Pension Plans | Non-U.S.
Change in projected benefit obligations ("PBO"):
Balance at beginning of the year	$ 513.3	$ 563.7
Service cost	6.0	6.6	6.3
Interest cost	19.9	18.9	19.8
Participant contributions	2.0	1.8
Actuarial (gains) losses	(47.7)	(16.2)
Settlements	(1.4)	(1.9)
Change in currency exchange rates	57.8	(36.8)
Benefits paid	(24.5)	(22.8)
Balance at end of the year	525.4	513.3	563.7
Change in plan assets:
Fair value at beginning of the year	404.9	422.6
Actual return on plan assets	13.9	20.0
Employer contributions	15.9	14.9
Participants' contributions	2.0	1.8
Settlements	(1.4)	(1.9)
Change in currency exchange rates	45.1	(29.7)
Benefits paid	(24.5)	(22.8)
Fair value at end of the year	455.9	404.9	$ 422.6
Funded status	(69.5)	(108.4)
Amounts recognized in the Consolidated Balance Sheets:
Noncurrent pension asset	11.4	9.1
Noncurrent accrued pension costs	(80.9)	(117.5)
Total	(69.5)	(108.4)
Accumulated other comprehensive loss:
Actuarial losses	44.9	88.8
Prior service cost	0.3	0.3
Total	45.2	89.1
Accumulated benefit obligations ("ABO")	$ 514.1	$ 499.7
Defined Benefit Plan, Funding Status [Extensible List]	us-gaap:FundedPlanMember	us-gaap:FundedPlanMember