Consolidated Statements of Cash Flows Parenthetical $ in Millions	6 Months Ended
Jun. 30, 2020 USD ($)
Statement of Cash Flows [Abstract]
Payments to Acquire Leasing Assets Net of Sold Railcars Owned One Year or Less Net Cost	$ 54.0

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