Partially-Owned Leasing Subsidiaries (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended				12 Months Ended		1 Months Ended				1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Partially-owned subsidiaries	Dec. 31, 2013 Railcar Leasing and Management Services Group Partially-owned subsidiaries subsidiaries	Dec. 31, 2013 Railcar Leasing and Management Services Group TRIP Rail Leasing	Aug. 31, 2013 Railcar Leasing and Management Services Group RIV 2013	Jul. 31, 2013 Railcar Leasing and Management Services Group RIV 2013	May 31, 2013 Railcar Leasing and Management Services Group RIV 2013	Dec. 31, 2013 Railcar Leasing and Management Services Group RIV 2013	May 31, 2013 Railcar Leasing and Management Services Group TRIP Holdings	Mar. 31, 2013 Railcar Leasing and Management Services Group TRIP Holdings	Dec. 31, 2013 Railcar Leasing and Management Services Group TRIP Holdings
Schedule of Investments [Line Items]
Number of subsidiaries					2
Number of board members					7
Number of TILC designated board members					2
Number of railcars owned						0
Date through which equity funding is committed										May 2016
Remaining equity commitment outstanding										$ 27.9
Remaining equity commitment outstanding from third parties										63.4
Date through which equity is committed, extended date										May 2019
Trinity guarantees of subsidiary-related activities				0
Purchase price of additional interest in TRIP Holdings	84.0	0	0								52.3	31.7
Reduction in carrying amount of noncontrolling interest from purchase of additional interest in TRIP Holdings	84.2											32.3
Proceeds from sale of interests in partially-owned leasing subsidiaries	296.7	0	0						94.6		200.3
Carrying value of investment in partially-owned subsidiary										44.6			160.2
Ownership percentage in partially-owned subsidiary										31.00%			45.00%
Contribution from TILC to RIV 2013								23.4
Contribution from third-party investors to RIV 2013	50.0	0	0					50.0
Purchase of equity interests by one investor from other investors							$ 2.5