Railcar Leasing and Management Services Group (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Revenues:
Total revenues	$ 1,012.9	$ 907.3	$ 995.5	$ 896.2	$ 914.3	$ 756.6	$ 674.3	$ 593.1	$ 3,811.9		$ 2,938.3		$ 1,930.7
Operating Profit:
Operating profit	158.9	140.7	152.5	122.7	139.5	104.6	95.4	87.3	574.8		426.8		294.2
Depreciation, interest, and rent expense:
Depreciation expense									193.7		187.7		180.9
Interest expense:
Total interest expense									194.7		185.3		182.1
Leasing Group
Revenues:
Total revenues									647.1		552.0		464.5
Percent Change									17.20%		18.80%
Operating Profit:
Operating profit									300.9		254.5		207.0
Operating profit margin:
Total operating profit margin									46.50%		46.10%		44.60%
Depreciation, interest, and rent expense:
Depreciation expense									120.5	[1]	115.7	[1]	112.6	[1]
Rent expense									50.9	[1]	48.6	[1]	48.6	[1]
Interest expense:
Total interest expense									174.3	[1]	160.8	[1]	138.6	[1]
Leasing Group | Leasing and management
Operating profit margin:
Total operating profit margin									45.90%		45.70%		43.40%
Leasing Group | Wholly-owned subsidiaries
Revenues:
Total revenues									528.4		434.5		348.5
Percent Change									21.60%		24.70%
Operating Profit:
Operating profit									232.8		181.3		138.5
Interest expense:
Total interest expense									101.2	[1]	101.3	[1]	91.7	[1]
Leasing Group | Wholly-owned subsidiaries | Leasing and management
Revenues:
Total revenues									409.8		375.1		345.4
Percent Change									9.30%		8.60%
Operating Profit:
Operating profit									175.2		156.3		131.7
Leasing Group | Wholly-owned subsidiaries | Railcar sales
Revenues:
Total revenues									118.6		59.4		3.1
Leasing Group | Wholly-owned subsidiaries | Railcars owned one year or less at the time of sale
Operating Profit:
Operating profit									24.8		13.2		0.2
Leasing Group | Wholly-owned subsidiaries | Railcars owned more than one year at the time of sale
Operating Profit:
Operating profit									32.8		11.8		6.6
Leasing Group | TRIP Holdings
Revenues:
Total revenues									118.7		117.5		116.0
Percent Change									1.00%		1.30%
Operating Profit:
Operating profit									68.1		73.2		68.5
Interest expense:
Interest expense external									60.0	[1]	53.1	[1]	46.9	[1]
Interest expense intercompany									13.1	[1]	6.4	[1]	0	[1]
Total interest expense									73.1	[1]	59.5	[1]	46.9	[1]
Leasing Group | TRIP Holdings | Leasing and management
Revenues:
Total revenues									118.7		117.5		116.0
Percent Change									1.00%		1.30%
Operating Profit:
Operating profit									67.4		68.8		68.5
Leasing Group | TRIP Holdings | Railcar sales
Revenues:
Total revenues									0		0		0
Percent Change									0.00%		0.00%
Leasing Group | TRIP Holdings | Railcars owned one year or less at the time of sale
Operating Profit:
Operating profit									0		0		0
Leasing Group | TRIP Holdings | Railcars owned more than one year at the time of sale
Operating Profit:
Operating profit									$ 0.7		$ 4.4		$ 0

[1] Depreciation 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 ownership of a portion of TRIP Holdings’ Senior Secured Notes and is eliminated in consolidation. See Note 11 Debt.