Defined contribution and defined benefit retirement plans - Components of Net Periodic Defined Benefit Pension Benefit Cost (Details) - Pension plans defined benefit - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined benefit pension plans [Line Items]
Expected contribution	$ 16.0
United States
Defined benefit pension plans [Line Items]
Interest cost	2.7	$ 2.2	$ 1.4
Expected return on plan assets	(3.2)	(1.9)	(2.0)
Recognized net actuarial losses	1.9	2.0	1.9
Total	1.4	2.3	1.3
Non U.S.
Defined benefit pension plans [Line Items]
Service cost	6.6	6.3	11.3
Interest cost	18.9	19.8	10.6
Expected return on plan assets	(19.9)	(18.3)	(11.1)
Recognized net actuarial losses	1.9	1.8	12.8
Amortization of prior service cost	0.1		0.1
Settlements	0.4	6.5	0.4
Total	$ 8.0	$ 16.1	$ 24.1