Partially-Owned Leasing Subsidiaries (Details Textual) (Leasing Group, USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 subsidiaries board_members
Partially-owned subsidiaries
Schedule of Investments [Line Items]
Number of subsidiaries	2
Number of board members	7
Number of TILC designated board members	2
Trinity guarantees of subsidiary-related activities	$ 0
TRIP Leasing
Schedule of Investments [Line Items]
Number of railcars owned	0
RIV 2013
Schedule of Investments [Line Items]
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
Carrying value of investment in partially-owned subsidiary	44.9
Ownership percentage in partially-owned subsidiary	31.00%
TRIP Holdings
Schedule of Investments [Line Items]
Carrying value of investment in partially-owned subsidiary	$ 161.3
Ownership percentage in partially-owned subsidiary	45.00%