Consolidated Statements of Cash Flows (unaudited) (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Capital expenditures – leasing, net of sold railcars owned one year or less, net cost	$ 53.1	$ 204.0

Payments to Acquire Leasing Assets Net of Sold Railcars Owned One Year or Less Net Cost

No definition available.

Name:	trn_PaymentstoAcquireLeasingAssetsNetofSoldRailcarsOwnedOneYearorLessNetCost
Namespace Prefix:	trn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration