Railcar Leasing and Management Services Group (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Revenues:
Total revenues	$ 1,066.1		$ 995.5		$ 1,999.0		$ 1,891.7
Operating profit:
Total operating profit	183.4		152.5		342.9		275.2
Selected expense information:
Depreciation					102.4		95.8
Interest:
Total interest expense	46.5		47.9		95.7		95.8
Leasing Group
Revenues:
Total revenues	169.6		194.2		304.0		336.5
Percent Change	(12.70%)				(9.70%)
Operating profit:
Total operating profit	75.7		76.4		137.3		142.9
Percentage Change	(0.90%)				(3.90%)
Operating profit margin:
Total operating profit margin	44.60%		39.30%		45.20%		42.50%
Selected expense information:
Depreciation	32.0	[1]	30.0	[1]	63.0	[1]	59.3	[1]
Percent Change, Depreciation	6.70%	[1]			6.20%	[1]
Maintenance	18.4	[1]	14.4	[1]	37.4	[1]	28.8	[1]
Percent Change, Maintenance	27.80%	[1]			29.90%	[1]
Rent	13.3	[1]	12.8	[1]	26.7	[1]	25.5	[1]
Percent Change, Rent	3.90%	[1]			4.70%	[1]
Interest:
External	38.0	[1]	39.3	[1]	78.9	[1]	79.1	[1]
Intercompany	1.1	[1]	3.2	[1]	3.8	[1]	6.5	[1]
Total interest expense	39.1	[1]	42.5	[1]	82.7	[1]	85.6	[1]
Percent Change, Total interest expense	(8.00%)	[1]			(3.40%)	[1]
Leasing Group | Leasing and management
Revenues:
Total revenues	150.7		132.0		285.0		259.4
Percent Change	14.20%				9.90%
Operating profit:
Total operating profit	71.0		61.3		125.8		121.2
Operating profit margin:
Total operating profit margin	47.10%		46.40%		44.10%		46.70%
Leasing Group | Railcar sales
Revenues:
Total revenues	18.9		62.2		19.0		77.1
Leasing Group | Railcars owned one year or less at the time of sale
Operating profit:
Total operating profit	3.5		13.5		3.5		16.4
Leasing Group | Railcars owned more than one year at the time of sale
Operating profit:
Total operating profit	$ 1.2		$ 1.6		$ 8.0		$ 5.3

[1] Depreciation, maintenance, and rent expense are components 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 previous ownership of a portion of TRIP Holdings’ Senior Secured Notes and is eliminated in consolidation. See Note 11 Debt.