Operating Assets and Facilities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 14,243.1		$ 14,243.1		$ 13,081.9
Less: allowance for depreciation	(3,866.7)		(3,866.7)		(3,670.7)
Operating assets and facilities, net	10,376.4		10,376.4		9,411.2
Total depreciation expense	108.0	$ 100.0	311.5	$ 289.4
Railcars and locomotives
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	12,703.5		12,703.5		11,700.8
Aircraft spare engines
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	935.8		935.8		769.7
Tank containers
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	256.4		256.4		237.7
Buildings, leasehold improvements, and other equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	257.1		257.1		253.0
Other
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 90.3		$ 90.3		$ 120.7