Other income (Schedule of Other Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Other income	$ 16.9	$ 15.3
Ancillary Product Profit Sharing [Member]
Disaggregation of Revenue [Line Items]
Other income	7.3	7.5
Interest [Member]
Disaggregation of Revenue [Line Items]
Other income	5.8	4.1
Remarketing Fees [Member]
Disaggregation of Revenue [Line Items]
Other income	3.3	3.0
Other [Member]
Disaggregation of Revenue [Line Items]
Other income	$ 0.5	$ 0.7