Leases (Assets Recorded Under Finance Leases) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Cost	$ 53.9	$ 50.5
Accumulated depreciation	(28.8)	(26.4)
Net book value	25.1	24.1
Auto equipment
Property, Plant and Equipment [Line Items]
Cost	27.6	22.1
Accumulated depreciation	(13.0)	(9.5)
Net book value	14.6	12.6
Computer equipment
Property, Plant and Equipment [Line Items]
Cost	15.4	14.3
Accumulated depreciation	(8.4)	(8.0)
Net book value	7.0	6.3
Yard and others
Property, Plant and Equipment [Line Items]
Cost	10.9	14.1
Accumulated depreciation	(7.4)	(8.9)
Net book value	$ 3.5	$ 5.2