Consolidated Statements of Cash Flows (unaudited) (Parenthetical) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017
Statement of Cash Flows [Abstract]
Capital expenditures – leasing, net of sold railcars owned one year or less, net cost	$ 63.2	$ 74.3

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