Additional borrowings debt instrument increase additional borrowings.

No definition available.

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Data Type:	xbrli:monetaryItemType
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- Definition

Additional equity ownership to be acquired from the equity investor by the company if the option was exercised to its fullest extent.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Contribution made by parent as a equity commitment during the period.

+ References

No definition available.

+ Details

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

- Definition

Equipment purchased by wholly owned subsidiary from the Company.

+ References

No definition available.

+ Details

Name:	trn_EquipmentPurchasedByWhollyOwnedSubsidiaryFromCompany
Namespace Prefix:	trn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Equity ownership interest in wholly owned subsidiary, percentage.

+ References

No definition available.

+ Details

Name:	trn_EquityOwnershipInterestInWhollyOwnedSubsidiaryPercentage
Namespace Prefix:	trn_
Data Type:	num:percentItemType
Balance Type:	na
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- Details

Name:	trn_InvestmentInSubsidiaryAdditionalTextualAbstract
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Data Type:	xbrli:stringItemType
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- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of other third-party equity investors in wholly owned subsidiary other than Company.

+ References

No definition available.

+ Details

Name:	trn_NumberOfOtherThirdPartyEquityInvestorsInWhollyOwnedSubsidiaryOtherThanCompany
Namespace Prefix:	trn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of equity investor's net investment specified as amount payable to equity investor.

+ References

No definition available.

+ Details

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Namespace Prefix:	trn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of the equity investor's net investment specified as amount payable to equity investor under certain limited circumstances.

+ References

No definition available.

+ Details

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Namespace Prefix:	trn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Remaining equity commitment outstanding.

+ References

No definition available.

+ Details

Name:	trn_RemainingEquityCommitmentOutstanding
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.4)

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

+ Details

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Data Type:	xbrli:monetaryItemType
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Investment in TRIP Holdings (Details Textual) (USD $) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended
	Jul. 31, 2011	Mar. 31, 2012	Mar. 31, 2011
Investment in TRIP Holdings (Textual) [Abstract]
Ownership percentage in TRIP Holdings		57.00%
Investment in Subsidiary (Additional Textual) [Abstract]
Railcars purchased by TRIP from the Company		$ 1,325.2
Number of other third-party equity investors in TRIP Holdings		3
TRIP Holdings [Member]
Investment in TRIP Holdings (Textual) [Abstract]
Remaining equity commitment by Trinity		0
Remaining equity commitment outstanding		0
Additional borrowings debt instrument increase additional borrowings	1,032.0
Payments to TILC from TRIP Holdings and TRIP leasing		$ 1.3	$ 0.9
Percentage of the equity investor's net investment specified as amount payable to equity investor		90.00%
Additional equity ownership to be acquired from the equity investor by the company if the option was exercised to its fullest extent		16.30%
Percentage of the equity investor's net investment specified as amount payable to equity investor under certain limited circumstances		100.00%