Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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Debt (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2009
Components of debt
Unamortized discount	$ 60.0	$ 74.1
Total debt	3,553.0us-gaap_DebtAndCapitalLeaseObligations	2,989.8us-gaap_DebtAndCapitalLeaseObligations
Notes payable	1,207.8us-gaap_NotesPayable	1,314.7us-gaap_NotesPayable
Carrying Value
Components of debt
Total debt	3,553.0	2,989.8
Recourse
Components of debt
Unamortized discount	60.0	74.1
Total debt	829.3	419.0
Recourse \| Carrying Value
Components of debt
Total debt	829.3	419.0
Recourse \| Capital lease obligations
Components of debt
Capital lease obligations			56.6
Non-recourse
Components of debt
Total debt	2,723.7	2,570.8
Corporate \| Recourse \| Carrying Value
Components of debt
Other	0.7	0.9
Total debt	790.2	376.8
Corporate \| Recourse \| Revolving credit facility \| Carrying Value
Components of debt
Revolving credit facility	0	0
Corporate \| Recourse \| Senior notes \| Carrying Value
Components of debt
Senior notes, net of unamortized discount of $0.4 and $-	399.6	0
Unamortized discount	0.4	0
Corporate \| Recourse \| Convertible subordinated notes \| Carrying Value
Components of debt
Convertible subordinated notes, net of unamortized discount of $59.6 and $74.1	389.9	375.9
Unamortized discount	59.6	74.1
Railcar Leasing and Management Services Group \| Wholly-owned subsidiaries
Components of debt
Total debt	1,246.9	1,356.9
Railcar Leasing and Management Services Group \| Partially-owned subsidiaries
Components of debt
Total debt	1,515.9	1,256.1
Railcar Leasing and Management Services Group \| Recourse \| Capital lease obligations
Components of debt
Capital lease obligations			56.6
Railcar Leasing and Management Services Group \| Recourse \| Capital lease obligations \| Carrying Value
Components of debt
Capital lease obligations	39.1	42.2
Railcar Leasing and Management Services Group \| Recourse \| Wholly-owned subsidiaries
Components of debt
Unamortized discount	0	0
Total debt	39.1	42.2
Railcar Leasing and Management Services Group \| Recourse \| Partially-owned subsidiaries
Components of debt
Unamortized discount	0	0
Total debt	0	0
Railcar Leasing and Management Services Group \| Non-recourse \| Carrying Value
Components of debt
Total debt	2,723.7	2,570.8
Railcar Leasing and Management Services Group \| Non-recourse \| Wholly-owned subsidiaries
Components of debt
Total debt	1,207.8	1,314.7
Railcar Leasing and Management Services Group \| Non-recourse \| Wholly-owned subsidiaries \| Carrying Value
Components of debt
Total debt	1,207.8	1,314.7
Railcar Leasing and Management Services Group \| Non-recourse \| Wholly-owned subsidiaries \| 2006 secured railcar equipment notes \| Carrying Value
Components of debt
Notes payable	223.0	240.7
Railcar Leasing and Management Services Group \| Non-recourse \| Wholly-owned subsidiaries \| Promissory notes \| Carrying Value
Components of debt
Notes payable	363.9	396.1
Railcar Leasing and Management Services Group \| Non-recourse \| Wholly-owned subsidiaries \| 2009 secured railcar equipment notes \| Carrying Value
Components of debt
Notes payable	188.8	199.0
Railcar Leasing and Management Services Group \| Non-recourse \| Wholly-owned subsidiaries \| 2010 secured railcar equipment notes \| Carrying Value
Components of debt
Notes payable	311.5	326.9
Railcar Leasing and Management Services Group \| Non-recourse \| Wholly-owned subsidiaries \| TILC warehouse facility \| Carrying Value
Components of debt
Revolving credit facility	120.6	152.0
Railcar Leasing and Management Services Group \| Non-recourse \| Partially-owned subsidiaries
Components of debt
Total debt	1,515.9	1,256.1
Railcar Leasing and Management Services Group \| Non-recourse \| Partially-owned subsidiaries \| Carrying Value
Components of debt
Notes payable	1,515.9	1,256.1
Railcar Leasing and Management Services Group \| Non-recourse \| Partially-owned subsidiaries \| TRL 2012 secured railcar equipment notes (RIV 2013) \| Carrying Value
Components of debt
Notes payable	472.2	499.3
Railcar Leasing and Management Services Group \| Non-recourse \| Partially-owned subsidiaries \| TRIP Master Funding secured railcar equipment notes \| Carrying Value
Components of debt
Notes payable	$ 1,043.7	$ 756.8