Railcar Leasing and Management Services Group (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Consolidating Financial Information
Cash, cash equivalents, and short-term marketable securities	$ 351.1	$ 512.0
Equipment, net pledged as collateral	4,711.0	4,648.6
Net deferred profit on railcars sold to the Leasing Group	(531.5)	(536.6)
Property, Plant and Equipment, net	4,179.5	4,112.0
Restricted cash of TRIP Holdings	240.3	207.1
Debt:
Recourse	557.5	561.4
Less: unamortized discount	(99.8)	(111.1)
Total Recourse	457.7	450.3
Non-recourse	2,626.0	2,457.4
Less: non-recourse debt owned by Trinity	(108.8)
Total debt	2,974.9	2,907.7
Net deferred tax liabilities	434.7	391.0
TRIP Holdings [Member]
Consolidating Financial Information
Restricted cash of TRIP Holdings	74.6	46.0
Debt:
Less: unamortized discount	(99.8)	(111.1)
Manufacturing/Corporate [Member]
Consolidating Financial Information
Cash, cash equivalents, and short-term marketable securities	347.9	508.2
Equipment, net pledged as collateral	510.0	491.4
Property, Plant and Equipment, net	510.0	491.4
Debt:
Recourse	454.2	452.8
Less: unamortized discount	(99.8)	(111.1)
Total Recourse	354.4	341.7
Total debt	354.4	341.7
Net deferred tax liabilities	(152.4)	(124.4)
Leasing Group [Member]
Debt:
Net deferred tax liabilities	434.7	391.0
Leasing Group [Member] | Wholly Owned Subsidiaries [Member]
Consolidating Financial Information
Cash, cash equivalents, and short-term marketable securities	3.2	3.8
Equipment, net pledged as collateral	3,066.0	2,965.4
Net deferred profit on railcars sold to the Leasing Group	(344.5)	(340.4)
Property, Plant and Equipment, net	2,721.5	2,625.0
Restricted cash of TRIP Holdings	165.7	161.1
Debt:
Recourse	103.3	108.6
Total Recourse	103.3	108.6
Non-recourse	1,616.0	1,453.5
Total debt	1,719.3	1,562.1
Net deferred tax liabilities	582.4	515.7
Leasing Group [Member] | TRIP Holdings [Member]
Consolidating Financial Information
Equipment, net pledged as collateral	1,135.0	1,191.8
Net deferred profit on railcars sold to the Leasing Group	(187.0)	(196.2)
Property, Plant and Equipment, net	948.0	995.6
Restricted cash of TRIP Holdings	74.6	46.0
Debt:
Non-recourse	1,010.0	1,003.9
Less: non-recourse debt owned by Trinity	(108.8)
Total debt	901.2	1,003.9
Net deferred tax liabilities	$ 4.7	$ (0.3)