Railcar Leasing and Management Services Group (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Operating Profit:
Total operating profit	$ 141.9		$ 105.4		$ 419.2		$ 286.3
Interest and rent expense:
Total interest expense	47.8		47.9		143.6		136.2
Leasing Group
Revenues:
Total revenues	159.9		147.4		496.4		395.4
Percent Change	8.50%				25.50%
Operating Profit:
Total operating profit	85.1		64.2		228.0		178.6
Operating profit margin:
Total operating profit margin	53.20%		43.60%		45.90%		45.20%
Interest and rent expense:
Rent expense	12.7	[1]	12.1	[1]	38.2	[1]	36.4	[1]
Total interest expense	42.6	[1]	43.3	[1]	128.2	[1]	116.2	[1]
Leasing Group | Leasing and management
Operating profit margin:
Total operating profit margin	46.70%		46.60%		46.70%		45.90%
Leasing Group | Wholly-owned subsidiaries
Revenues:
Total revenues	129.8		118.2		407.4		308.0
Percent Change	9.80%				32.30%
Operating Profit:
Total operating profit	67.3	[2]	46.8	[2]	176.5	[2]	127.2	[2]
Interest and rent expense:
Total interest expense	24.3	[1]	24.8	[1]	73.2	[1]	75.4	[1]
Leasing Group | Wholly-owned subsidiaries | Leasing and management
Revenues:
Total revenues	106.4		94.6		306.9		277.8
Percent Change	12.50%				10.50%
Operating Profit:
Total operating profit	47.1		40.3		134.2		116.3
Leasing Group | Wholly-owned subsidiaries | Railcar sales
Revenues:
Total revenues	23.4	[2]	23.6	[2]	100.5	[2]	30.2	[2]
Leasing Group | Wholly-owned subsidiaries | Railcars owned one year or less at the time of sale
Operating Profit:
Total operating profit	4.3	[2]	4.9	[2]	20.7	[2]	7.9	[2]
Leasing Group | Wholly-owned subsidiaries | Railcars owned more than one year at the time of sale
Operating Profit:
Total operating profit	15.9	[2]	1.6	[2]	21.6	[2]	3.0	[2]
Leasing Group | TRIP Holdings
Revenues:
Total revenues	30.1		29.2		89.0		87.4
Percent Change	3.10%				1.80%
Operating Profit:
Total operating profit	17.8	[2]	17.4	[2]	51.5	[2]	51.4	[2]
Interest and rent expense:
Interest expense external	15.0	[1]	15.3	[1]	45.2	[1]	37.6	[1]
Interest expense intercompany	3.3	[1]	3.2	[1]	9.8	[1]	3.2	[1]
Total interest expense	18.3	[1]	18.5	[1]	55.0	[1]	40.8	[1]
Leasing Group | TRIP Holdings | Leasing and management
Revenues:
Total revenues	30.1		29.2		89.0		87.4
Percent Change	3.10%				1.80%
Operating Profit:
Total operating profit	16.7		17.4		50.8		51.3
Leasing Group | TRIP Holdings | Railcar sales
Revenues:
Total revenues	0	[2]	0	[2]	0	[2]	0	[2]
Percent Change	0.00%	[2]			0.00%	[2]
Leasing Group | TRIP Holdings | Railcars owned one year or less at the time of sale
Operating Profit:
Total operating profit	0	[2]	0	[2]	0	[2]	0	[2]
Leasing Group | TRIP Holdings | Railcars owned more than one year at the time of sale
Operating Profit:
Total operating profit	$ 1.1	[2]	$ 0	[2]	$ 0.7	[2]	$ 0.1	[2]

[1] Rent expense is a component of operating profit. Interest expense is not a component of operating profit and includes the effect of hedges. Intercompany interest expense arises from Trinity’s ownership of a portion of TRIP Holdings’ Senior Secured Notes and is eliminated in consolidation. See Note 11 Debt.

[2] Effective December 31, 2011, the Company adopted the emerging industry policy of recognizing revenue from the sales of railcars from the lease fleet on a gross basis in leasing revenues and cost of revenues if the railcar has been owned by the lease fleet for one year or less at the time of sale. Sales of railcars from the lease fleet which have been owned by the lease fleet for more than one year are recognized as a net gain or loss from the disposal of a long-term asset. Prior year reported balances have been reclassified to conform to this policy.