Segment information - Customer Revenue by Classes of Similar Products or Services (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenue from External Customer [Line Items]
Revenue	$ 2,015.4	$ 1,979.9	$ 2,054.4
Operating Segments
Revenue from External Customer [Line Items]
Revenue	1,725.1	1,699.9	1,747.2
Segment Reconciling Items
Revenue from External Customer [Line Items]
Revenue	290.3	280.0	308.6
Elimination
Revenue from External Customer [Line Items]
Revenue	$ 0.0	$ 0.0	$ (1.4)