Property, Plant, and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	$ 7,981.0	$ 7,145.4
Less: accumulated depreciation	(2,014.2)	(1,797.4)
Property, plant, and equipment, net	5,966.8	5,348.0
Manufacturing/Corporate
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	1,936.1	1,861.5
Less: accumulated depreciation	(974.4)	(905.4)
Property, plant, and equipment, net	961.7	956.1
Partially-owned subsidiaries
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	1,979.8	1,980.1
Less: accumulated depreciation	(364.9)	(313.7)
Land | Manufacturing/Corporate
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	103.3	86.5
Buildings and improvements | Manufacturing/Corporate
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	642.6	610.4
Machinery and other | Manufacturing/Corporate
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	1,151.1	1,095.9
Construction in progress | Manufacturing/Corporate
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	39.1	68.7
Operating Segments
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, net	6,764.9	6,021.0
Operating Segments | Manufacturing/Corporate
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, net	961.7	956.1
Operating Segments | Leasing Group | Wholly-owned subsidiaries
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	4,683.7	3,774.2
Less: accumulated depreciation	(760.1)	(647.9)
Property, plant, and equipment, net	3,923.6	3,126.3
Operating Segments | Leasing Group | Partially-owned subsidiaries
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, net	1,879.6	1,938.6
Operating Segments | Machinery and other | Leasing Group | Wholly-owned subsidiaries
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	10.7	10.7
Operating Segments | Equipment on lease | Leasing Group | Wholly-owned subsidiaries
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	4,673.0	3,763.5
Operating Segments | Equipment on lease | Leasing Group | Partially-owned subsidiaries
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	2,309.4	2,307.7
Less: accumulated depreciation	(429.8)	(369.1)
Net deferred profit on railcars sold to Leasing Group
Property, Plant and Equipment [Line Items]
Property, plant and equipment, at cost	(948.2)	(798.0)
Less: accumulated depreciation	150.1	125.0
Property, plant, and equipment, net	$ (798.1)	$ (673.0)