Debt (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Components of debt
Less: unamortized discount	$ (84.2)	[1]	$ (87.5)
Notes payable	1,714.0	[1]	1,738.0
Total debt	2,974.8	[1]	3,055.0
Carrying Value
Components of debt
Total debt	2,974.8		3,055.0	[2]
Recourse
Components of debt
Less: unamortized discount	(84.2)		(87.5)
Total debt	412.0		458.1
Recourse | Carrying Value
Components of debt
Total debt	412.0		458.1	[2]
Non-Recourse
TRIP Holdings senior secured notes:
Less: owned by Trinity	(108.8)		(108.8)
Manufacturing/Corporate
Components of debt
Total debt	366.9		363.7
Manufacturing/Corporate | Recourse
Components of debt
Less: unamortized discount			(87.5)
Total debt	366.9		363.7
Manufacturing/Corporate | Recourse | Carrying Value
Components of debt
Revolving credit facility	0		0	[2]
Convertible subordinated notes	450.0		450.0	[2]
Less: unamortized discount	(84.2)		(87.5)	[2]
Convertible subordinated notes, net	365.8		362.5	[2]
Other	1.1		1.2	[2]
Total debt	366.9		363.7	[2]
Manufacturing/Corporate | Non-Recourse
TRIP Holdings senior secured notes:
Less: owned by Trinity	0		0
Railcar Leasing and Management Services Group | Wholly-owned subsidiaries
Components of debt
Total debt	1,759.1		1,832.4
Railcar Leasing and Management Services Group | Recourse | Wholly-owned subsidiaries
Components of debt
Less: unamortized discount	0		0
Total debt	45.1		94.4
Railcar Leasing and Management Services Group | Recourse | Wholly-owned subsidiaries | Carrying Value
Components of debt
Total debt	45.1		94.4	[2]
Railcar Leasing and Management Services Group | Recourse | Wholly-owned subsidiaries | Capital lease obligations | Carrying Value
Components of debt
Capital lease obligations	45.1		45.8	[2]
Railcar Leasing and Management Services Group | Recourse | Wholly-owned subsidiaries | Term loan | Carrying Value
Components of debt
Loans payable	0		48.6	[2]
Railcar Leasing and Management Services Group | Non-Recourse | Carrying Value
Components of debt
Total debt	2,562.8		2,596.9	[2]
Railcar Leasing and Management Services Group | Non-Recourse | TRIP Master Funding secured railcar equipment notes | Carrying Value
Components of debt
Notes payable	787.6		797.7	[2]
Railcar Leasing and Management Services Group | Non-Recourse | Wholly-owned subsidiaries
TRIP Holdings senior secured notes:
Less: owned by Trinity	0		0
Railcar Leasing and Management Services Group | Non-Recourse | Wholly-owned subsidiaries | 2006 secured railcar equipment notes | Carrying Value
Components of debt
Notes payable	252.2		255.8	[2]
Railcar Leasing and Management Services Group | Non-Recourse | Wholly-owned subsidiaries | Promissory notes | Carrying Value
Components of debt
Notes payable	418.2		424.1	[2]
Railcar Leasing and Management Services Group | Non-Recourse | Wholly-owned subsidiaries | 2009 secured railcar equipment notes | Carrying Value
Components of debt
Notes payable	206.7		209.2	[2]
Railcar Leasing and Management Services Group | Non-Recourse | Wholly-owned subsidiaries | 2010 secured railcar equipment notes | Carrying Value
Components of debt
Notes payable	337.9		341.5	[2]
Railcar Leasing and Management Services Group | Non-Recourse | Wholly-owned subsidiaries | 2012 secured railcar equipment notes | Carrying Value
Components of debt
Notes payable	331.1		333.8	[2]
Railcar Leasing and Management Services Group | Non-Recourse | Wholly-owned subsidiaries | TILC warehouse facility | Carrying Value
Components of debt
Loans payable	167.9		173.6	[2]
Railcar Leasing and Management Services Group | Non-Recourse | TRIP Holdings | TRIP Holdings senior secured notes | Carrying Value
TRIP Holdings senior secured notes:
Total outstanding	170.0		170.0	[2]
Less: owned by Trinity	(108.8)		(108.8)	[2]
TRIP Holdings senior secured notes	$ 61.2		$ 61.2	[2]

[1] (unaudited)

[2] (as reported)