Contract with customer, asset and liability (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Contract with Customer, Asset, before Allowance for Credit Loss	$ 522.9	$ 502.2	$ 443.2
change in contract asset	20.7	59.0
Contract with Customer, Liability	(353.9)	(356.4)	(387.0)
change in contract liability	2.5	30.6
Contract with Customer, Liability, Revenue Recognized	189.4	72.8
Contracts with Customers, Net Contract Asset (Liability)	169.0	145.8	$ 56.2
change in net contract asset	$ 23.2	$ 89.6