Property, Plant and Equipment (Schedule of Property, Plant and Equipment) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Cost	$ 1,671.3	$ 851.9
Accumulated depreciation	(470.4)	(392.8)
Net book value	1,200.9	459.1
Land
Property, Plant and Equipment [Line Items]
Cost	549.2	169.4
Accumulated depreciation	0.0	0.0
Net book value	549.2	169.4
Buildings and improvements
Property, Plant and Equipment [Line Items]
Cost	491.1	444.4
Accumulated depreciation	(236.1)	(220.5)
Net book value	255.0	223.9
Yard, automotive and office equipment
Property, Plant and Equipment [Line Items]
Cost	306.0	124.4
Accumulated depreciation	(117.5)	(83.1)
Net book value	188.5	41.3
Computer software and equipment
Property, Plant and Equipment [Line Items]
Cost	108.2	83.0
Accumulated depreciation	(79.5)	(72.5)
Net book value	28.7	10.5
Leasehold improvements
Property, Plant and Equipment [Line Items]
Cost	160.0	23.4
Accumulated depreciation	(37.3)	(16.7)
Net book value	122.7	6.7
Assets under development
Property, Plant and Equipment [Line Items]
Cost	56.8	7.3
Accumulated depreciation	0.0	0.0
Net book value	$ 56.8	$ 7.3