Railcar Leasing and Management Services Group (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Consolidating Financial Information
Cash and cash equivalents	$ 573.0	$ 351.1
Property, plant, and equipment, net	4,861.7	4,690.6
Net deferred profit on railcars sold to the Leasing Group	(562.7)	(531.5)
Property, plant, and equipment, net	4,299.0	4,159.1
Restricted cash	223.2	240.3
Debt:
Less: unamortized discount	(87.5)	(99.8)
Total debt	3,055.0	2,972.2
Net deferred tax liabilities	555.8	434.7
Recourse
Debt:
Recourse	545.6	554.8
Less: unamortized discount	(87.5)	(99.8)
Total debt	458.1	455.0
Non-Recourse
Debt:
Non-recourse	2,705.7	2,626.0
Less: non-recourse debt owned by Trinity	(108.8)	(108.8)
TRIP Holdings
Consolidating Financial Information
Restricted cash	50.3	74.6
Leasing Group | Wholly-owned subsidiaries
Consolidating Financial Information
Cash and cash equivalents	5.7	3.2
Property, plant, and equipment, net	3,203.8	3,066.0
Net deferred profit on railcars sold to the Leasing Group	(381.8)	(344.5)
Property, plant, and equipment, net	2,822.0	2,721.5
Restricted cash	172.9	165.7
Debt:
Total debt	1,832.4	1,719.3
Net deferred tax liabilities	671.1	582.4
Leasing Group | Wholly-owned subsidiaries | Recourse
Debt:
Recourse	94.4	103.3
Less: unamortized discount	0	0
Total debt	94.4	103.3
Leasing Group | Wholly-owned subsidiaries | Non-Recourse
Debt:
Non-recourse	1,738.0	1,616.0
Less: non-recourse debt owned by Trinity	0	0
Leasing Group | TRIP Holdings
Consolidating Financial Information
Cash and cash equivalents	0	0
Property, plant, and equipment, net	1,118.6	1,135.0
Net deferred profit on railcars sold to the Leasing Group	(180.9)	(187.0)
Property, plant, and equipment, net	937.7	948.0
Restricted cash	50.3	74.6
Debt:
Total debt	858.9	901.2
Net deferred tax liabilities	5.4	4.7
Leasing Group | TRIP Holdings | Recourse
Debt:
Recourse	0	0
Less: unamortized discount	0	0
Total debt	0	0
Leasing Group | TRIP Holdings | Non-Recourse
Debt:
Non-recourse	967.7	1,010.0
Less: non-recourse debt owned by Trinity	(108.8)	(108.8)
Manufacturing/Corporate
Consolidating Financial Information
Cash and cash equivalents	567.3	347.9
Property, plant, and equipment, net	539.3	489.6
Net deferred profit on railcars sold to the Leasing Group	0	0
Property, plant, and equipment, net	539.3	489.6
Restricted cash	0	0
Debt:
Total debt	363.7	351.7
Net deferred tax liabilities	(120.7)	(152.4)
Manufacturing/Corporate | Recourse
Debt:
Recourse	451.2	451.5
Less: unamortized discount		(99.8)
Total debt	363.7	351.7
Manufacturing/Corporate | Non-Recourse
Debt:
Non-recourse	0	0
Less: non-recourse debt owned by Trinity	0	0
Carrying Value
Debt:
Total debt	3,055.0	2,972.2
Carrying Value | Recourse
Debt:
Total debt	458.1	455.0
Carrying Value | Leasing Group | Non-Recourse
Debt:
Total debt	2,596.9	2,517.2
Carrying Value | Leasing Group | Wholly-owned subsidiaries | Recourse
Debt:
Total debt	94.4	103.3
Carrying Value | Manufacturing/Corporate | Recourse
Debt:
Less: unamortized discount	(87.5)	(99.8)
Total debt	$ 363.7	$ 351.7