Net Book Value of Unpledged Equipment.

No definition available.

Name:	trn_NetBookValueofUnpledgedEquipment
Namespace Prefix:	trn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of assets pledged to secure a debt instrument.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

Name:	us-gaap_DebtInstrumentCollateralAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12069-110248

+ Details

Name:	us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980

+ Details

Name:	us-gaap_LesseeOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Term of lessor's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=77888428&loc=SL77919359-209981

+ Details

Name:	us-gaap_LessorOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Railcar Leasing and Management Services Group - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2014
Minimum
Segment Reporting Information [Line Items]
Period of railcars leased under operating leases (in years)	1 year
Maximum
Segment Reporting Information [Line Items]
Period of railcars leased under operating leases (in years)	40 years
Railcar Leasing and Management Services Group \| Minimum
Segment Reporting Information [Line Items]
Term of leases with third parties (in years)	1 year
Railcar Leasing and Management Services Group \| Maximum
Segment Reporting Information [Line Items]
Term of leases with third parties (in years)	10 years	20 years
Corporate Segment [Member] \| Senior Notes [Member] \| 4.55% Senior Notes Due October 2024 [Member]
Segment Reporting Information [Line Items]
Debt Instrument, Interest Rate, Stated Percentage			4.55%
Wholly-owned subsidiaries \| Railcar Leasing and Management Services Group
Segment Reporting Information [Line Items]
Net book value of unpledged equipment	$ 1,652.6
Wholly-owned subsidiaries \| Railcar Leasing and Management Services Group \| Non-recourse debt
Segment Reporting Information [Line Items]
Collateral securing debt	$ 3,742.9
Wholly-Owned Qualified Subsidiaries for Leasing Railcars from Trusts [Member] \| Railcar Leasing and Management Services Group \| Railroad transportation equipment leased from independent owner trusts
Segment Reporting Information [Line Items]
Period of railcars leased under operating leases (in years)	22 years
TRIP Holdings \| Railcar Leasing and Management Services Group \| Non-recourse debt \| TRIP Master Funding secured railcar equipment notes
Segment Reporting Information [Line Items]
Collateral securing debt	$ 1,258.2
TRL 2012 \| Railcar Leasing and Management Services Group \| Non-recourse debt \| TRL 2012 secured railcar equipment notes
Segment Reporting Information [Line Items]
Collateral securing debt	552.1
Property Lease Guarantee [Member] \| Railcar Leasing and Management Services Group
Segment Reporting Information [Line Items]
Operating lease obligations guaranteed	$ 1.2