Debt (Details) - USD ($) $ in Millions	Jun. 30, 2016		Dec. 31, 2015
Debt Instrument [Line Items]
Unamortized discount	$ 35.8	[1]	$ 44.2
Less: unamortized debt issuance costs	(4.3)		(4.8)
Recourse, net of unamortized discount of $35.8 and $44.2	843.9	[1]	836.7
Non-recourse debt	2,314.8		2,390.7
Less: unamortized debt issuance costs	(29.1)		(32.0)
Non-recourse debt	2,285.7		2,358.7
Total debt	3,129.6	[1]	3,195.4
Wholly-owned subsidiaries
Debt Instrument [Line Items]
Non-recourse debt	892.4	[1]	928.7
Partially-owned subsidiaries
Debt Instrument [Line Items]
Non-recourse debt	1,393.3	[1]	1,430.0
Corporate
Debt Instrument [Line Items]
Corporate - Recourse	814.1		805.7
Less: unamortized debt issuance costs	(4.2)		(4.7)
Long-term debt, net of debt issuance costs	809.9		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	34.0		35.7
Non-recourse debt	2,285.7		2,358.7
Railcar Leasing and Management Services Group | Wholly-owned subsidiaries
Debt Instrument [Line Items]
Non-recourse debt	905.6		943.8
Less: unamortized debt issuance costs	(13.2)		(15.1)
Non-recourse debt	892.4		928.7
Railcar Leasing and Management Services Group | Partially-owned subsidiaries
Debt Instrument [Line Items]
Non-recourse debt	1,409.2		1,446.9
Less: unamortized debt issuance costs	(15.9)		(16.9)
Non-recourse debt	1,393.3		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	240.5		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	35.4		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	414.0		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	201.3		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	175.8		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	288.0		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	436.8		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	$ 972.4		$ 997.8

[1] (unaudited)