Defined contribution and defined benefit retirement plans - Schedule of Plans for which Accumulated Benefit Obligations Exceeds Plan Assets (Details) - Pension plans defined benefit - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
United States
Plans for which the ABO exceeds plan assets:
Projected benefit obligations	$ 0.1	$ 42.7
Accumulated benefit obligations	0.1	42.7
Fair value of plan assets		40.3
Non U.S.
Plans for which the ABO exceeds plan assets:
Projected benefit obligations	397.1	463.1
Accumulated benefit obligations	387.1	452.9
Fair value of plan assets	$ 279.5	$ 313.8