Property, Plant, and Equipment (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Components of property, plant, and equipment
Less: accumulated depreciation	$ (1,683.1)	$ (1,505.2)
Property, plant, and equipment, net before adjustment to net deferred profit	5,460.1	5,320.3
Net deferred profit on railcars sold to the Leasing Group	(557.2)	(549.7)
Property, plant, and equipment, net	4,902.9	4,770.6
Partially-owned subsidiaries
Components of property, plant, and equipment
Less: accumulated depreciation	(261.3)	(202.1)
Manufacturing/ Corporate
Components of property, plant, and equipment
Property, plant and equipment	1,681.7	1,418.9
Less: accumulated depreciation	(820.7)	(748.3)
Property, plant, and equipment, net before adjustment to net deferred profit	861.0	670.6
Leasing Group
Components of property, plant, and equipment
Net deferred profit on railcars sold to the Leasing Group	(557.2)	(549.7)
Leasing Group | Wholly-owned subsidiaries
Components of property, plant, and equipment
Property, plant and equipment	3,200.3	3,519.4
Less: accumulated depreciation	(601.1)	(554.8)
Property, plant, and equipment, net before adjustment to net deferred profit	2,599.2	2,964.6
Leasing Group | Partially-owned subsidiaries
Components of property, plant, and equipment
Property, plant, and equipment, net before adjustment to net deferred profit	1,999.9	1,685.1
Land | Manufacturing/ Corporate
Components of property, plant, and equipment
Property, plant and equipment	81.4	44.2
Buildings and improvements | Manufacturing/ Corporate
Components of property, plant, and equipment
Property, plant and equipment	548.2	463.2
Machinery and other | Manufacturing/ Corporate
Components of property, plant, and equipment
Property, plant and equipment	975.7	832.5
Machinery and other | Leasing Group | Wholly-owned subsidiaries
Components of property, plant, and equipment
Property, plant and equipment	10.7	10.3
Construction in progress | Manufacturing/ Corporate
Components of property, plant, and equipment
Property, plant and equipment	76.4	79.0
Equipment on lease | Leasing Group | Wholly-owned subsidiaries
Components of property, plant, and equipment
Property, plant and equipment	3,189.6	3,509.1
Equipment on lease | Leasing Group | Partially-owned subsidiaries
Components of property, plant, and equipment
Property, plant and equipment	2,261.2	1,887.2
Less: accumulated depreciation	$ (261.3)	$ (202.1)