Railcar Leasing and Management Services Group (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Revenues:
Total revenues	$ 1,661.4	$ 1,562.8	$ 1,485.3	$ 1,460.5	$ 1,256.0	$ 1,110.3	$ 1,066.1	$ 932.9	$ 6,170.0		$ 4,365.3		$ 3,811.9
Operating profit:
Total operating profit	276.5	281.2	302.0	391.3	224.4	205.6	183.4	159.5	1,251.0		772.9		574.8
Selected expense information:
Depreciation									244.6		211.5		193.7
Interest:
Total interest expense									193.4		187.3		194.7
Total
Revenues:
Total revenues									6,170.0		4,365.3		3,811.9
Railcar Leasing and Management Services Group
Revenues:
Total revenues									1,106.4		645.4		644.4
Operating profit:
Total operating profit									516.3		296.8		300.9
Operating profit margin:
Total operating profit margin									46.20%		46.00%		46.50%
Selected expense information:
Depreciation									130.0	[1]	129.0	[1]	120.5	[1]
Percent Change, Depreciation									0.80%	[1]	7.10%	[1]
Maintenance									78.9	[1]	71.5	[1]	59.4	[1]
Percent Change, Maintenance									10.30%	[1]	20.40%	[1]
Rent									52.9	[1]	53.3	[1]	50.9	[1]
Percent Change, Rent									(0.80%)	[1]	4.70%	[1]
Interest:
Total interest expense									153.3	[1]	153.5	[1]	161.2	[1]
Railcar Leasing and Management Services Group | Intercompany
Interest:
Total interest expense									0	[1]	3.8	[1]	13.1	[1]
Railcar Leasing and Management Services Group | Total
Revenues:
Total revenues									1,118.3		645.4		647.1
Percent Change, Revenues									73.30%		(0.30%)
Operating profit:
Total operating profit									516.3		296.8		300.9
Percentage Change, Operating profit									74.00%		(1.40%)
Interest:
Total interest expense									153.3	[1]	157.3	[1]	174.3	[1]
Percent Change, Total interest expense									(2.50%)	[1]	(9.80%)	[1]
Railcar Leasing and Management Services Group | Leasing and management
Revenues:
Total revenues									632.0		586.9		528.5
Percent Change, Revenues									7.70%		11.10%
Operating profit:
Total operating profit									287.9		267.3		242.6
Percentage Change, Operating profit									7.70%		10.20%
Operating profit margin:
Total operating profit margin									45.60%		45.50%		45.90%
Railcar Leasing and Management Services Group | Railcars owned one year or less at the time of sale
Revenues:
Total revenues									486.3		58.5		118.6
Operating profit:
Total operating profit									136.1		9.1		24.8
Railcar Leasing and Management Services Group | Railcars owned more than one year at the time of sale
Operating profit:
Total operating profit									$ 92.3		$ 20.4		$ 33.5

[1] Depreciation, maintenance, and rent expense are components of operating profit. Amortization of deferred profit on railcars sold from the Rail Group to the Leasing Group is included in the operating profit of the Leasing Group resulting in the recognition of depreciation expense based on the Company's original manufacturing cost of the railcars. Interest expense is not a component of operating profit and includes the effect of hedges. Intercompany interest expense is eliminated in consolidation and arises from Trinity’s previous ownership of a portion of TRIP Holdings’ Senior Secured Notes, which notes were retired in full in May 2013. See Note 11 Debt.