Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Total revenues	$ 1,184.9	$ 1,676.8	$ 2,372.8	$ 3,303.5
Operating Profit (Loss)	191.6	382.9	395.0	716.0
Intersegment
Segment Reporting Information [Line Items]
Total revenues	329.3	319.4	697.8	676.1
Intersegment | Eliminations – Lease subsidiary
Segment Reporting Information [Line Items]
Total revenues	(252.1)	(215.5)	(535.4)	(474.5)
Operating Profit (Loss)	(45.9)	(49.9)	(111.4)	(98.2)
Intersegment | Eliminations – Other
Segment Reporting Information [Line Items]
Total revenues	(77.2)	(103.9)	(162.4)	(201.6)
Operating Profit (Loss)	0.2	1.5	1.6	2.6
Total
Segment Reporting Information [Line Items]
Total revenues	1,514.2	1,996.2	3,070.6	3,979.6
Operating Profit (Loss)	272.0	463.6	564.2	870.6
Corporate
Segment Reporting Information [Line Items]
Operating Profit (Loss)	(34.7)	(32.3)	(59.4)	(59.0)
Rail Group
Segment Reporting Information [Line Items]
Total revenues	427.7	884.2	970.9	1,759.6
Rail Group | Intersegment
Segment Reporting Information [Line Items]
Total revenues	265.5	226.1	569.2	495.2
Rail Group | Total
Segment Reporting Information [Line Items]
Total revenues	693.2	1,110.3	1,540.1	2,254.8
Operating Profit (Loss)	88.8	227.7	246.0	440.4
Construction Products Group
Segment Reporting Information [Line Items]
Total revenues	141.7	148.9	263.3	260.3
Construction Products Group | Intersegment
Segment Reporting Information [Line Items]
Total revenues	4.1	2.4	7.4	3.8
Construction Products Group | Total
Segment Reporting Information [Line Items]
Total revenues	145.8	151.3	270.7	264.1
Operating Profit (Loss)	21.5	21.3	37.4	29.6
Inland Barge Group
Segment Reporting Information [Line Items]
Total revenues	118.3	187.8	229.1	340.9
Inland Barge Group | Intersegment
Segment Reporting Information [Line Items]
Total revenues	0.0	0.0	0.0	0.0
Inland Barge Group | Total
Segment Reporting Information [Line Items]
Total revenues	118.3	187.8	229.1	340.9
Operating Profit (Loss)	14.3	40.7	26.9	68.2
Energy Equipment Group
Segment Reporting Information [Line Items]
Total revenues	199.1	223.3	431.6	464.8
Energy Equipment Group | Intersegment
Segment Reporting Information [Line Items]
Total revenues	41.5	58.6	82.4	117.2
Energy Equipment Group | Total
Segment Reporting Information [Line Items]
Total revenues	240.6	281.9	514.0	582.0
Operating Profit (Loss)	34.9	36.3	72.3	73.5
Railcar Leasing and Management Services Group
Segment Reporting Information [Line Items]
Total revenues	296.1	231.4	473.9	475.6
Railcar Leasing and Management Services Group | Intersegment
Segment Reporting Information [Line Items]
Total revenues	0.5	6.7	1.2	7.3
Railcar Leasing and Management Services Group | Total
Segment Reporting Information [Line Items]
Total revenues	296.6	238.1	475.1	482.9
Operating Profit (Loss)	117.7	137.7	191.9	260.5
All Other
Segment Reporting Information [Line Items]
Total revenues	2.0	1.2	4.0	2.3
All Other | Intersegment
Segment Reporting Information [Line Items]
Total revenues	17.7	25.6	37.6	52.6
All Other | Total
Segment Reporting Information [Line Items]
Total revenues	19.7	26.8	41.6	54.9
Operating Profit (Loss)	$ (5.2)	$ (0.1)	$ (10.3)	$ (1.6)