Debt (Details) - USD ($) $ in Millions	Mar. 31, 2016		Dec. 31, 2015
Debt Instrument [Line Items]
Unamortized discount	$ 40.0	[1]	$ 44.2
Less: unamortized debt issuance costs	(4.5)		(4.8)
Recourse, net of unamortized discount of $40.0 and $44.2	840.4	[1]	836.7
Non-recourse debt	2,361.1		2,390.7
Less: unamortized debt issuance costs	(30.5)		(32.0)
Non-recourse debt	2,330.6		2,358.7
Total debt	3,171.0	[1]	3,195.4
Wholly-owned subsidiaries
Debt Instrument [Line Items]
Non-recourse debt	917.5	[1]	928.7
Partially-owned subsidiaries
Debt Instrument [Line Items]
Non-recourse debt	1,413.1	[1]	1,430.0
Corporate
Debt Instrument [Line Items]
Corporate - Recourse	809.9		805.7
Less: unamortized debt issuance costs	(4.4)		(4.7)
Long-term debt, net of debt issuance costs	805.5		801.0
Railcar Leasing and Management Services Group
Debt Instrument [Line Items]
Capital lease obligations, net of unamortized debt issuances costs of $0.1 and $0.1	34.9		35.7
Non-recourse debt	2,330.6		2,358.7
Railcar Leasing and Management Services Group | Wholly-owned subsidiaries
Debt Instrument [Line Items]
Non-recourse debt	931.6		943.8
Less: unamortized debt issuance costs	(14.1)		(15.1)
Non-recourse debt	917.5		928.7
Railcar Leasing and Management Services Group | Partially-owned subsidiaries
Debt Instrument [Line Items]
Non-recourse debt	1,429.5		1,446.9
Less: unamortized debt issuance costs	(16.4)		(16.9)
Non-recourse debt	1,413.1		1,430.0
Line of credit | Revolving credit facility | Corporate
Debt Instrument [Line Items]
Corporate - Recourse	0.0		0.0
Line of credit | Revolving credit facility | Railcar Leasing and Management Services Group | TILC warehouse facility | Wholly-owned subsidiaries
Debt Instrument [Line Items]
Non-recourse debt	259.3		264.3
Senior notes, net of unamortized discount of $0.4 and $0.4 | Corporate
Debt Instrument [Line Items]
Corporate - Recourse	399.6		399.6
Unamortized discount	0.4		0.4
Convertible subordinated notes, net of unamortized discount | Corporate
Debt Instrument [Line Items]
Unamortized discount	39.6		43.8
Convertible subordinated notes, net of unamortized discount | Corporate | 3 7/8% Convertible Subordinated Notes Due 2036 [Member]
Debt Instrument [Line Items]
Corporate - Recourse	409.8		405.6
Other | Corporate
Debt Instrument [Line Items]
Corporate - Recourse	0.5		0.5
Capital lease obligations, net of unamortized debt issuances costs of $0.1 and $0.1 | Railcar Leasing and Management Services Group
Debt Instrument [Line Items]
Less: unamortized debt issuance costs	(0.1)		(0.1)
Non-recourse debt | Railcar Leasing and Management Services Group | 2006 secured railcar equipment notes | Wholly-owned subsidiaries
Debt Instrument [Line Items]
Non-recourse debt	202.8		204.1
Non-recourse debt | Railcar Leasing and Management Services Group | 2009 secured railcar equipment notes | Wholly-owned subsidiaries
Debt Instrument [Line Items]
Non-recourse debt	177.4		179.2
Non-recourse debt | Railcar Leasing and Management Services Group | 2010 secured railcar equipment notes | Wholly-owned subsidiaries
Debt Instrument [Line Items]
Non-recourse debt	292.1		296.2
Non-recourse debt | Railcar Leasing and Management Services Group | TRL 2012 secured railcar equipment notes (RIV 2013) | Partially-owned subsidiaries
Debt Instrument [Line Items]
Non-recourse debt	443.6		449.1
Non-recourse debt | Railcar Leasing and Management Services Group | TRIP Master Funding secured railcar equipment notes (TRIP Holdings) | Partially-owned subsidiaries
Debt Instrument [Line Items]
Non-recourse debt	$ 985.9		$ 997.8

[1] (unaudited)