Debt (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011
Components of debt
Less: unamortized discount	$ (90.7)	[1]	$ (99.8)
Notes payable	1,646.9	[1]	1,616.0
Total debt	2,978.1	[1]	2,974.9
Carrying Value
Components of debt
Total debt	2,978.1		2,974.9
Recourse
Components of debt
Less: unamortized discount	(90.7)		(99.8)
Total debt	462.3		457.7
Recourse | Carrying Value
Components of debt
Total debt	462.3		457.7
Non-Recourse
TRIP Holdings senior secured notes:
Less: owned by Trinity	(108.8)		(108.8)
Manufacturing/Corporate
Components of debt
Total debt	364.4		354.4
Manufacturing/Corporate | Recourse
Components of debt
Less: unamortized discount			(99.8)
Total debt	364.4		354.4
Manufacturing/Corporate | Recourse | Carrying Value
Components of debt
Revolving credit facility	0		0
Convertible subordinated notes	450.0		450.0
Less: unamortized discount	(90.7)		(99.8)
Convertible subordinated notes, total	359.3		350.2
Other	5.1		4.2
Total debt	364.4		354.4
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	1,744.8		1,719.3
Railcar Leasing and Management Services Group | TRIP Holdings
Components of debt
Total debt	868.9		901.2
Railcar Leasing and Management Services Group | Recourse | Wholly-owned subsidiaries
Components of debt
Less: unamortized discount	0		0
Total debt	97.9		103.3
Railcar Leasing and Management Services Group | Recourse | Wholly-owned subsidiaries | Carrying Value
Components of debt
Total debt	97.9		103.3
Railcar Leasing and Management Services Group | Recourse | Wholly-owned subsidiaries | Capital lease obligations | Carrying Value
Components of debt
Capital lease obligations	46.5		48.6
Railcar Leasing and Management Services Group | Recourse | Wholly-owned subsidiaries | Term loan | Carrying Value
Components of debt
Loans payable	51.4		54.7
Railcar Leasing and Management Services Group | Recourse | TRIP Holdings
Components of debt
Less: unamortized discount	0		0
Total debt	0		0
Railcar Leasing and Management Services Group | Non-Recourse | Carrying Value
Components of debt
Total debt	2,515.8		2,517.2
Railcar Leasing and Management Services Group | Non-Recourse | TRIP Master Funding secured railcar equipment notes | Carrying Value
Components of debt
Notes payable	807.7		840.0
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	259.1		269.3
Railcar Leasing and Management Services Group | Non-Recourse | Wholly-owned subsidiaries | Promissory notes | Carrying Value
Components of debt
Notes payable	445.5		465.5
Railcar Leasing and Management Services Group | Non-Recourse | Wholly-owned subsidiaries | 2009 secured railcar equipment notes | Carrying Value
Components of debt
Notes payable	211.6		218.4
Railcar Leasing and Management Services Group | Non-Recourse | Wholly-owned subsidiaries | 2010 secured railcar equipment notes | Carrying Value
Components of debt
Notes payable	345.0		354.3
Railcar Leasing and Management Services Group | Non-Recourse | Wholly-owned subsidiaries | TILC warehouse facility | Carrying Value
Components of debt
Loans payable	385.7		308.5
Railcar Leasing and Management Services Group | Non-Recourse | TRIP Holdings
TRIP Holdings senior secured notes:
Less: owned by Trinity	(108.8)		(108.8)
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
Less: owned by Trinity	(108.8)		(108.8)
TRIP Holdings senior secured notes	$ 61.2		$ 61.2

[1] (unaudited)