Fair Value Accounting (Details 2) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Gross	$ 881.5	$ 885.7
Less: unamortized discount	(27.1)	(44.2)
Less: unamortized debt issuance costs	(3.8)	(4.8)
Recourse, net of unamortized discount and unamortized debt issuance costs	850.6	836.7
Non-recourse debt	2,232.4	2,390.7
Less: unamortized debt issuance costs	(26.4)	(32.0)
Non-recourse debt, net of unamortized debt issuance costs	2,206.0	2,358.7
Total debt	3,056.6	3,195.4
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including unamortized debt issuance costs, net of unamortized discount	854.4	841.5
Less: unamortized debt issuance costs	(3.8)	(4.8)
Recourse, net of unamortized discount and unamortized debt issuance costs	850.6	836.7
Non-recourse debt	2,232.4	2,390.7
Less: unamortized debt issuance costs	(26.4)	(32.0)
Non-recourse debt, net of unamortized debt issuance costs	2,206.0	2,358.7
Total debt	3,056.6	3,195.4
Carrying Value | 2006 secured railcar equipment notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recourse debt	194.2	204.1
Carrying Value | 2009 secured railcar equipment notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recourse debt	172.5	179.2
Carrying Value | 2010 secured railcar equipment notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recourse debt	280.6	296.2
Carrying Value | TRL 2012 secured railcar equipment notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recourse debt	425.5	449.1
Carrying Value | TRIP Master Funding secured railcar equipment notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recourse debt	955.5	997.8
Carrying Value | Senior notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including unamortized debt issuance costs, net of unamortized discount	399.6	399.6
Carrying Value | Convertible subordinated notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including unamortized debt issuance costs, net of unamortized discount	422.7	405.6
Long-term Debt, Gross	449.4	449.4
Less: unamortized discount	(26.7)	(43.8)
Carrying Value | Capital lease obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including unamortized debt issuance costs, net of unamortized discount	32.1	35.8
Carrying Value | Other
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including unamortized debt issuance costs, net of unamortized discount	0.0	0.5
Carrying Value | Line of credit | TILC warehouse facility | Revolving credit facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recourse debt	204.1	264.3
Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including unamortized debt issuance costs, net of unamortized discount	993.9	941.4
Non-recourse debt	2,236.0	2,480.3
Total debt	3,229.9	3,421.7
Estimated Fair Value | 2006 secured railcar equipment notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recourse debt	201.5	218.2
Estimated Fair Value | 2009 secured railcar equipment notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recourse debt	189.9	207.2
Estimated Fair Value | 2010 secured railcar equipment notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recourse debt	284.3	314.2
Estimated Fair Value | TRL 2012 secured railcar equipment notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recourse debt	395.6	436.9
Estimated Fair Value | TRIP Master Funding secured railcar equipment notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recourse debt	960.6	1,039.5
Estimated Fair Value | Senior notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including unamortized debt issuance costs, net of unamortized discount	386.3	370.3
Estimated Fair Value | Convertible subordinated notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Gross	575.5	534.8
Estimated Fair Value | Capital lease obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including unamortized debt issuance costs, net of unamortized discount	32.1	35.8
Estimated Fair Value | Other
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including unamortized debt issuance costs, net of unamortized discount	0.0	0.5
Estimated Fair Value | Line of credit | TILC warehouse facility | Revolving credit facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recourse debt	$ 204.1	$ 264.3