Railcar Leasing and Management Services Group (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended			13 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	Dec. 31, 2014	Dec. 31, 2009
Railcar Leasing and Management Services Group (Textual) [Abstract]
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
Proceeds from railcar lease fleet sales owned more than one year at the time of sale									265.8	131.6	126.3
Assets	8,733.8				7,313.4				8,733.8	7,313.4		8,733.8
Recourse | Capital lease obligations
Railcar Leasing and Management Services Group (Textual) [Abstract]
Capital lease obligations													56.6
Rail Group
Railcar Leasing and Management Services Group (Textual) [Abstract]
Revenues									3,077.6	2,093.5	1,512.1
Railcar Leasing and Management Services Group
Railcar Leasing and Management Services Group (Textual) [Abstract]
Revenues									1,106.4	645.4	644.4
Operating lease obligations guaranteed by Trinity Industries, Inc. and certain subsidiaries	17.6								17.6			17.6
Railcar Leasing and Management Services Group | Wholly-owned subsidiaries
Railcar Leasing and Management Services Group (Textual) [Abstract]
Net book value of equipment pledged as collateral	1,841.9								1,841.9			1,841.9
Net book value of equipment securing capital lease obligations	45.6								45.6			45.6
Net book value of unpledged equipment	672.8								672.8			672.8
Railcar Leasing and Management Services Group | TRIP Holdings
Railcar Leasing and Management Services Group (Textual) [Abstract]
Net book value of equipment pledged as collateral	1,398.1								1,398.1			1,398.1
Railcar Leasing and Management Services Group | TRL 2012
Railcar Leasing and Management Services Group (Textual) [Abstract]
Net book value of equipment pledged as collateral	601.7								601.7			601.7
Railcar Leasing and Management Services Group | Wholly owned qualified subsidiaries for leasing railcars from the Trusts
Railcar Leasing and Management Services Group (Textual) [Abstract]
Period of railcars leased from the Trusts under operating leases (in years)									22 years
First year to exercise the option to purchase at a predetermined fixed price certain of the railcars from the Trusts									2016
Second year to exercise the option to purchase at a predetermined fixed price certain of the railcars from the Trusts									2019
First year to exercise the option to purchase railcars at the end of the respective lease agreements									2023
Second year to exercise the option to purchase railcars at the end of the respective lease agreements									2026
Third year to exercise the option to purchase railcars at the end of the respective lease agreements									2027
Assets	195.5								195.5			195.5
Cash	71.1								71.1			71.1
Railcars	83.7								83.7			83.7
Railcar Leasing and Management Services Group | Recourse | Capital lease obligations
Railcar Leasing and Management Services Group (Textual) [Abstract]
Capital lease obligations													56.6
Railcar Leasing and Management Services Group | Minimum
Railcar Leasing and Management Services Group (Textual) [Abstract]
Term of leases with third parties (in years)									1 year
Railcar Leasing and Management Services Group | Maximum
Railcar Leasing and Management Services Group (Textual) [Abstract]
Term of leases with third parties (in years)									20 years
Railcar Leasing and Management Services Group | Railcars owned one year or less at the time of sale
Railcar Leasing and Management Services Group (Textual) [Abstract]
Revenues									486.3	58.5	118.6
Element
Railcar Leasing and Management Services Group (Textual) [Abstract]
Proceeds from sale leased railcars									882.7			987.7
Element | Rail Group
Railcar Leasing and Management Services Group (Textual) [Abstract]
Revenues									200.4
Element | Railcar Leasing and Management Services Group | Railcars owned one year or less at the time of sale
Railcar Leasing and Management Services Group (Textual) [Abstract]
Revenues									446.6
Proceeds from railcar lease fleet sales owned more than one year at the time of sale									$ 235.7