Borrowings on Warehouse Loan Facility

No definition available.

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

- Definition

Long-term Debt, Net of Unamortized Discount, Gross of Unamortized Debt Issuance Costs

+ References

No definition available.

+ Details

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

- Definition

Non-Recourse Debt, Gross

+ References

No definition available.

+ Details

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

- Definition

Non-Recourse Debt, Gross of Issuance Cost, Net of Discount

+ References

No definition available.

+ Details

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

- Definition

Repayments on Warehouse Loan Facility

+ References

No definition available.

+ Details

Name:	trn_RepaymentsonWarehouseLoanFacility
Namespace Prefix:	trn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69C
-URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69B
-URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612

+ Details

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

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123466204&loc=SL6036836-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629

Reference 4: 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=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Incremental percentage increase (decrease) in the stated rate on a debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentInterestRateIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

Name:	us-gaap_ExtinguishmentOfDebtAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=123467658&loc=d3e12355-112629

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=123467658&loc=d3e12317-112629

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

+ Details

Name:	us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the 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))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

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

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

The effective interest rate at the end of the reporting period.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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

- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest.

+ References

+ Details

Name:	us-gaap_PaymentsOfDebtExtinguishmentCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.

+ References

+ Details

Name:	us-gaap_PaymentsOfDebtIssuanceCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(f))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

Name:	us-gaap_ProceedsFromLinesOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(f))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

Name:	us-gaap_RepaymentsOfLinesOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

+ Details

Name:	us-gaap_WriteOffOfDeferredDebtIssuanceCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=us-gaap_CorporateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_A4.55SeniorNotesDueOctober2024Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=trn_RailcarLeasingAndManagementServicesGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_TRIPRailcarCoTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=trn_PartiallyOwnedSubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=trn_WhollyOwnedSubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_A2009SecuredRailcarEquipmentNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_A2010SecuredRailcarEquipmentNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_A2017SecuredRailcarEquipmentNotesMemberDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_A2018SecuredRailcarEquipmentNotesDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_A2018ClassA1SecuredRailcarEquipmentNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_A2018ClassA2SecuredRailcarEquipmentNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_A2018ClassA20201SecuredRailcarEquipmentNotesDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_TrinityRailLeasing2019Domain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_A2019SecuredRailcarEquipmentNotesDomainDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_A2019SecuredRailcarEquipmentNotesClassA1NotesDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_A2019SecuredRailcarEquipmentNotesClassA2NotesDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_A2020SecuredRailcarEquipmentNotesClassA1NotesDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_A2020SecuredRailcarEquipmentNotesClassA2NotesDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_A2020SecuredRailcarEquipmentNotesClassBNotesDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=trn_PromissoryNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=trn_TILCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_TRL2021Series20211GreenSecuredRailcarEquipmentNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_TRL2021Series20211ClassAGreenSecuredRailcarEquipmentNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_TRL2021Series20211ClassBGreenSecuredRailcarEquipmentNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_TilcWarehouseFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=trn_PartiallyOwnedSubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_TRP2021SecuredRailcarEquipmentNotesRIV2013Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=trn_TripHoldingsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_TriumphRailClassASecuredRailcarEquipmentNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_TriumphRailClassBSecuredRailcarEquipmentNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_TriumphRailSecuredRailcarEquipmentNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=trn_RIV2013HoldingsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_TRP2021ClassASecuredRailcarEquipmentNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=trn_TRP2021ClassBSecuredRailcarEquipmentNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 8. Debt (Details) - USD ($) $ in Millions	12 Months Ended
Note 8. Debt (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Loss on extinguishment of debt	$ 11.7	$ 5.0	$ 0.0
Corporate Segment [Member]
Debt Instrument [Line Items]
Long-term Debt, Net of Unamortized Discount, Gross of Unamortized Debt Issuance Costs	399.9	449.8
Corporate Segment [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Long-term Debt, Net of Unamortized Discount, Gross of Unamortized Debt Issuance Costs	$ 399.9	399.8
Corporate Segment [Member] \| Senior Notes [Member] \| 4.55% Senior Notes Due October 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.55%
Debt Instrument, Face Amount	$ 400.0
Railcar Leasing and Management Services Group [Member] \| Line of Credit [Member] \| TRIP Railcar Co Term Loan
Debt Instrument [Line Items]
Long-term Line of Credit	323.7	0.0
Revolving Credit Facility [Member] \| Corporate Segment [Member] \| Line of Credit [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	450.0
Proceeds from Lines of Credit	470.0
Repayments of Lines of Credit	520.0
Long-term Debt, Net of Unamortized Discount, Gross of Unamortized Debt Issuance Costs	0.0	50.0
Line of Credit Facility, Remaining Borrowing Capacity	421.7
Line of Credit Facility, Maximum Borrowing Capacity	$ 176.8
Debt Instrument, Interest Rate, Effective Percentage	1.75%
Line of Credit Facility, Interest Rate at Period End	0.25%
Revolving Credit Facility [Member] \| Corporate Segment [Member] \| Line of Credit [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	0.30%
Line of Credit Facility, Interest Rate at Period End	0.175%
Revolving Credit Facility [Member] \| Corporate Segment [Member] \| Line of Credit [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate at Period End	0.40%
Letter of Credit [Member] \| Corporate Segment [Member] \| Line of Credit [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount	$ 28.3
Partially-Owned Subsidiaries [Member] \| Railcar Leasing and Management Services Group [Member]
Debt Instrument [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	38.00%
Wholly Owned Subsidiaries [Member] \| Secured Debt [Member] \| 2009 Secured Railcar Equipment Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.66%
Debt Instrument, Face Amount	$ 238.3
Wholly Owned Subsidiaries [Member] \| Secured Debt [Member] \| 2010 Secured Railcar Equipment Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.19%
Debt Instrument, Face Amount	$ 369.2
Wholly Owned Subsidiaries [Member] \| Secured Debt [Member] \| 2017 Secured Railcar Equipment Notes [Member] [Domain]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	1.63%
Debt Instrument, Face Amount	$ 225.0		$ 663.0	$ 302.4
Wholly Owned Subsidiaries [Member] \| Secured Debt [Member] \| 2018 Secured Railcar Equipment Notes [Domain]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 482.5
Wholly Owned Subsidiaries [Member] \| Secured Debt [Member] \| 2018 Class A-1 Secured Railcar Equipment Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.82%
Debt Instrument, Face Amount	$ 200.0
Wholly Owned Subsidiaries [Member] \| Secured Debt [Member] \| 2018 Class A-2 Secured Railcar Equipment Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.62%
Debt Instrument, Face Amount	$ 282.5
Non-Recourse Debt, Gross	$ 282.5
Wholly Owned Subsidiaries [Member] \| Secured Debt [Member] \| 2018 Class A 2020-1 Secured Railcar Equipment Notes [Domain]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.96%
Debt Instrument, Face Amount	$ 155.5
Extinguishment of Debt, Amount		153.1
Non-Recourse Debt, Gross	134.1
Wholly Owned Subsidiaries [Member] \| Secured Debt [Member] \| Trinity Rail Leasing 2019 [Domain]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 386.5
Wholly Owned Subsidiaries [Member] \| Secured Debt [Member] \| 2019 Secured Railcar Equipment Notes [Domain] [Domain]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.82%
Debt Instrument, Face Amount	$ 528.3
Non-Recourse Debt, Gross	$ 468.8
Wholly Owned Subsidiaries [Member] \| Secured Debt [Member] \| 2019 Secured Railcar Equipment Notes Class A1 Notes [Domain]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.39%
Debt Instrument, Face Amount	$ 106.9
Non-Recourse Debt, Gross	$ 74.7
Wholly Owned Subsidiaries [Member] \| Secured Debt [Member] \| 2019 Secured Railcar Equipment Notes Class A2 Notes [Domain]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.10%
Debt Instrument, Face Amount	$ 279.6
Non-Recourse Debt, Gross	$ 279.6
Wholly Owned Subsidiaries [Member] \| Secured Debt [Member] \| 2020 Secured Railcar Equipment Notes Class A1 Notes [Domain]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.83%
Debt Instrument, Face Amount	$ 110.0
Non-Recourse Debt, Gross	$ 88.1
Wholly Owned Subsidiaries [Member] \| Secured Debt [Member] \| 2020 Secured Railcar Equipment Notes Class A2 Notes [Domain]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.56%
Debt Instrument, Face Amount	$ 240.3
Non-Recourse Debt, Gross	$ 240.3
Wholly Owned Subsidiaries [Member] \| Secured Debt [Member] \| 2020 Secured Railcar Equipment Notes Class B Notes [Domain]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.69%
Debt Instrument, Face Amount	$ 20.5
Non-Recourse Debt, Gross	20.5
Wholly Owned Subsidiaries [Member] \| Railcar Leasing and Management Services Group [Member]
Debt Instrument [Line Items]
Non-Recourse Debt, Gross of Issuance Cost, Net of Discount	3,579.5	3,364.5
Wholly Owned Subsidiaries [Member] \| Railcar Leasing and Management Services Group [Member] \| 2009 Secured Railcar Equipment Notes [Member]
Debt Instrument [Line Items]
Non-Recourse Debt, Gross	128.5	142.3
Wholly Owned Subsidiaries [Member] \| Railcar Leasing and Management Services Group [Member] \| 2010 Secured Railcar Equipment Notes [Member]
Debt Instrument [Line Items]
Non-Recourse Debt, Gross	220.6	235.9
Wholly Owned Subsidiaries [Member] \| Railcar Leasing and Management Services Group [Member] \| 2018 Secured Railcar Equipment Notes [Domain]
Debt Instrument [Line Items]
Non-Recourse Debt, Gross of Issuance Cost, Net of Discount	416.5	434.7
Wholly Owned Subsidiaries [Member] \| Railcar Leasing and Management Services Group [Member] \| 2019 Secured Railcar Equipment Notes [Domain] [Domain]
Debt Instrument [Line Items]
Non-Recourse Debt, Gross of Issuance Cost, Net of Discount	822.8	860.5
Wholly Owned Subsidiaries [Member] \| Railcar Leasing and Management Services Group [Member] \| Promissory Notes [Member] \| 2017 Secured Railcar Equipment Notes [Member] [Domain]
Debt Instrument [Line Items]
Non-Recourse Debt, Gross	768.0
Non-Recourse Debt, Gross of Issuance Cost, Net of Discount	$ 760.2	802.7
Debt Instrument, Interest Rate, Increase (Decrease)	1.50%
TILC [Member] \| Railcar Leasing and Management Services Group [Member] \| Secured Debt [Member] \| TRL-2021 Series 2021-1Green Secured Railcar Equipment Notes
Debt Instrument [Line Items]
Payments of Debt Issuance Costs	$ 3.3
Proceeds from Issuance of Debt	$ 214.4
TILC [Member] \| Railcar Leasing and Management Services Group [Member] \| Secured Debt [Member] \| TRL-2021 Series 2021-1 Class A Green Secured Railcar Equipment Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.26%
Debt Instrument, Face Amount	$ 305.2
Non-Recourse Debt, Gross	$ 300.5
TILC [Member] \| Railcar Leasing and Management Services Group [Member] \| Secured Debt [Member] \| TRL-2021 Series 2021-1 Class B Green Secured Railcar Equipment Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.08%
Debt Instrument, Face Amount	$ 19.8
Non-Recourse Debt, Gross	19.8
TILC [Member] \| Revolving Credit Facility [Member] \| Railcar Leasing and Management Services Group [Member] \| Line of Credit [Member] \| TILC Warehouse Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity	438.2
Line of Credit Facility, Maximum Borrowing Capacity	$ 250.0
Debt Instrument, Interest Rate, Effective Percentage	1.95%
Debt Instrument, Face Amount	$ 1,000.0	750.0
Long-term Line of Credit	561.8	519.4
Borrowings on Warehouse Loan Facility	425.1
Repayments on Warehouse Loan Facility	382.7
Partially-Owned Subsidiaries [Member] \| Railcar Leasing and Management Services Group [Member]
Debt Instrument [Line Items]
Non-Recourse Debt, Gross	1,227.2	1,237.5
Partially-Owned Subsidiaries [Member] \| Railcar Leasing and Management Services Group [Member] \| TRL 2012 Secured Railcar Equipment Notes - RIV 2013 [Member]
Debt Instrument [Line Items]
Non-Recourse Debt, Gross	$ 352.2	$ 352.5
TRIP Holdings \| Railcar Leasing and Management Services Group [Member] \| Secured Debt [Member] \| Triumph Rail Class A Secured Railcar Equipment Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.15%
Debt Instrument, Face Amount	$ 535.0
Non-Recourse Debt, Gross	$ 526.1
TRIP Holdings \| Railcar Leasing and Management Services Group [Member] \| Secured Debt [Member] \| Triumph Rail Class B Secured Railcar Equipment Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.08%
Debt Instrument, Face Amount	$ 25.4
Non-Recourse Debt, Gross	25.4
TRIP Holdings \| Railcar Leasing and Management Services Group [Member] \| Secured Debt [Member] \| Triumph Rail Secured Railcar Equipment Notes
Debt Instrument [Line Items]
Extinguishment of Debt, Amount	869.1
Loss on extinguishment of debt	(8.7)
Payments of Debt Issuance Costs	$ 5.6
Debt, Weighted Average Interest Rate	5.16%
Payment for Debt Extinguishment or Debt Prepayment Cost	$ 3.3
Write off of Deferred Debt Issuance Cost	5.4
TRIP Holdings \| Railcar Leasing and Management Services Group [Member] \| Secured Debt [Member] \| TRIP Railcar Co Term Loan
Debt Instrument [Line Items]
Proceeds from Lines of Credit	$ 329.6
Debt Instrument, Interest Rate, Effective Percentage	1.95%
Payments of Debt Issuance Costs	$ 2.9
Debt Instrument, Interest Rate, Increase (Decrease)	1.85%
RIV 2013 Holdings \| Railcar Leasing and Management Services Group [Member] \| Secured Debt [Member] \| TRP-2021 Class A Secured Railcar Equipment Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.07%
Debt Instrument, Face Amount	$ 334.0
Non-Recourse Debt, Gross	$ 331.3
RIV 2013 Holdings \| Railcar Leasing and Management Services Group [Member] \| Secured Debt [Member] \| TRP 2021 Class B Secured Railcar Equipment Notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.06%
Debt Instrument, Face Amount	$ 21.0
Non-Recourse Debt, Gross	21.0
RIV 2013 Holdings \| Railcar Leasing and Management Services Group [Member] \| Secured Debt [Member] \| TRL 2012 Secured Railcar Equipment Notes - RIV 2013 [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Amount	348.0
Payments of Debt Issuance Costs	$ 3.7
Debt, Weighted Average Interest Rate	3.59%
Write off of Deferred Debt Issuance Cost	$ 3.0