Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Total revenues	$ 1,111.7	$ 1,542.2	$ 3,484.5	$ 4,845.7
Operating Profit (Loss)	183.6	364.9	578.6	1,080.9
Intersegment
Segment Reporting Information [Line Items]
Total revenues	289.9	418.6	987.7	1,094.7
Intersegment | Eliminations – Lease subsidiary
Segment Reporting Information [Line Items]
Total revenues	(206.7)	(308.4)	(742.1)	(782.9)
Operating Profit (Loss)	(27.7)	(65.6)	(139.1)	(163.8)
Intersegment | Eliminations – Other
Segment Reporting Information [Line Items]
Total revenues	(83.2)	(110.2)	(245.6)	(311.8)
Operating Profit (Loss)	(0.4)	(1.1)	1.2	1.5
Total
Segment Reporting Information [Line Items]
Total revenues	1,401.6	1,960.8	4,472.2	5,940.4
Operating Profit (Loss)	247.3	471.3	811.5	1,341.9
Corporate
Segment Reporting Information [Line Items]
Operating Profit (Loss)	(35.6)	(39.7)	(95.0)	(98.7)
Rail Group
Segment Reporting Information [Line Items]
Total revenues	506.0	747.2	1,476.9	2,506.8
Rail Group | Intersegment
Segment Reporting Information [Line Items]
Total revenues	214.8	326.2	784.0	821.4
Rail Group | Total
Segment Reporting Information [Line Items]
Total revenues	720.8	1,073.4	2,260.9	3,328.2
Operating Profit (Loss)	103.6	223.3	349.6	663.7
Construction Products Group
Segment Reporting Information [Line Items]
Total revenues	136.3	151.1	399.6	411.4
Construction Products Group | Intersegment
Segment Reporting Information [Line Items]
Total revenues	3.5	3.7	10.9	7.5
Construction Products Group | Total
Segment Reporting Information [Line Items]
Total revenues	139.8	154.8	410.5	418.9
Operating Profit (Loss)	23.8	19.9	61.2	49.5
Inland Barge Group
Segment Reporting Information [Line Items]
Total revenues	98.9	164.8	328.0	505.7
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	98.9	164.8	328.0	505.7
Operating Profit (Loss)	11.7	28.1	38.6	96.3
Energy Equipment Group
Segment Reporting Information [Line Items]
Total revenues	194.6	229.6	626.2	694.4
Energy Equipment Group | Intersegment
Segment Reporting Information [Line Items]
Total revenues	47.1	59.9	129.5	177.1
Energy Equipment Group | Total
Segment Reporting Information [Line Items]
Total revenues	241.7	289.5	755.7	871.5
Operating Profit (Loss)	31.2	44.8	103.5	118.3
Railcar Leasing and Management Services Group
Segment Reporting Information [Line Items]
Total revenues	173.2	246.6	647.1	722.2
Railcar Leasing and Management Services Group | Intersegment
Segment Reporting Information [Line Items]
Total revenues	0.5	2.6	1.7	9.9
Railcar Leasing and Management Services Group | Total
Segment Reporting Information [Line Items]
Total revenues	173.7	249.2	648.8	732.1
Operating Profit (Loss)	80.5	158.2	272.4	418.7
All Other
Segment Reporting Information [Line Items]
Total revenues	2.7	2.9	6.7	5.2
All Other | Intersegment
Segment Reporting Information [Line Items]
Total revenues	24.0	26.2	61.6	78.8
All Other | Total
Segment Reporting Information [Line Items]
Total revenues	26.7	29.1	68.3	84.0
Operating Profit (Loss)	$ (3.5)	$ (3.0)	$ (13.8)	$ (4.6)