Restructuring Activities (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Impaired Assets to be Disposed of by Method Other than Sale, Fair Value of Asset		$ 191.7
Impaired Assets to be Disposed of by Method Other than Sale, Carrying Value of Asset		550.0
Impairment of Long-Lived Assets Held-for-use		358.3
Operating Lease, Impairment Loss		$ 11.1
Restructuring Reserve	$ 2.7				$ 2.7		$ 3.4
Employee severance costs	3.4				7.5
Charges and adjustments					8.1
Non-cash impact of restructuring activities	0.7		$ 5.2		5.9	$ 0.0
Asset impairment charges:					2.4
Payments					(8.8)
Restructuring Charges	(4.7)			$ 0.0	(10.5)	$ 0.0
Loss on Contract Termination	0.6				0.6
Gain (Loss) on Disposition of Assets					(3.5)
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	2.1				2.1
Contract Termination
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0.6				0.6		$ 0.0
Operating Segments [Member] | Railcar Leasing and Management Services Group [Member]
Restructuring Cost and Reserve [Line Items]
Employee severance costs	1.4				1.4
Non-cash impact of restructuring activities	0.0				0.0
Restructuring Charges	(1.4)				(1.4)
Loss on Contract Termination	0.0				0.0
Gain (Loss) on Disposition of Assets					0.0
Operating Segments [Member] | Rail Products Group [Member]
Restructuring Cost and Reserve [Line Items]
Employee severance costs	1.3				3.9
Non-cash impact of restructuring activities	0.7				0.7
Restructuring Charges	(2.2)				(4.8)
Loss on Contract Termination	0.2				0.2
Gain (Loss) on Disposition of Assets					0.0
Operating Segments [Member] | Other Segments [Member]
Restructuring Cost and Reserve [Line Items]
Employee severance costs	0.1				0.2
Non-cash impact of restructuring activities	0.0				0.0
Restructuring Charges	(0.1)				(3.3)
Loss on Contract Termination	0.0				0.0
Gain (Loss) on Disposition of Assets					(3.5)
Operating Segments [Member] | Corporate, Non-Segment [Member]
Restructuring Cost and Reserve [Line Items]
Employee severance costs	0.6				2.0
Non-cash impact of restructuring activities	0.0				5.2
Restructuring Charges	(1.0)				(7.6)
Loss on Contract Termination	$ 0.4				0.4
Gain (Loss) on Disposition of Assets					$ 0.0