Derivative Instruments and Fair Value Measurements - Assets and Liabilities Recorded at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 28, 2024	Dec. 30, 2023
Manufacturing group
Assets and Liabilities Recorded at Fair Value on a Recurring Basis
Forward exchange contracts maximum maturity period	3 years
Manufacturing group \| Foreign currency exchange contracts \| Cash Flow Hedging
Assets and Liabilities Recorded at Fair Value on a Recurring Basis
Notional amounts	$ 604	$ 478
Manufacturing group \| Foreign currency exchange contracts \| Cash Flow Hedging \| Level 2
Assets and Liabilities Recorded at Fair Value on a Recurring Basis
Derivative asset, fair value	6	4
Derivative liability, fair value	4	3
Finance group \| Interest rate swap \| Cash Flow Hedging
Assets and Liabilities Recorded at Fair Value on a Recurring Basis
Derivative asset, fair value	1	4
Finance group \| Interest Rate Swap, Maturing August 2025 To August 2029 \| Cash Flow Hedging
Assets and Liabilities Recorded at Fair Value on a Recurring Basis
Notional amounts	$ 264
Finance group \| Interest Rate Swap, Maturing August 2025 To August 2029 \| Cash Flow Hedging \| Junior Subordinated Debt
Assets and Liabilities Recorded at Fair Value on a Recurring Basis
Net impact of debt and derivative, weighted-average fixed interest rate	5.20%
Finance group \| Interest Rate Swap, Maturing August 2025 To August 2030 \| Cash Flow Hedging
Assets and Liabilities Recorded at Fair Value on a Recurring Basis
Notional amounts	$ 30	$ 185
Finance group \| Interest Rate Swap, Maturing August 2025 To August 2030 \| Cash Flow Hedging \| Junior Subordinated Debt
Assets and Liabilities Recorded at Fair Value on a Recurring Basis
Net impact of debt and derivative, weighted-average fixed interest rate	5.10%	5.17%
Finance group \| Interest rate swap, maturing in June 2025 \| Cash Flow Hedging
Assets and Liabilities Recorded at Fair Value on a Recurring Basis
Notional amounts	$ 25	$ 25
Net impact of debt and derivative, fixed interest rate	4.13%	4.13%

Fixed Rate, Net Impact of Debt And Derivative Instrument

No definition available.

Name:	txt_FixedRateNetImpactOfDebtAndDerivativeInstrument
Namespace Prefix:	txt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted Average Fixed Rate, Net Impact Of Debt And Derivative Instrument

+ References

No definition available.

+ Details

Name:	txt_WeightedAverageFixedRateNetImpactOfDebtAndDerivativeInstrument
Namespace Prefix:	txt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair value of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, not subject to a master netting arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)
-SubTopic 20
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483466/210-20-50-3

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 210
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483444/210-20-55-22

+ Details

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

- Definition

Fair value of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, not subject to a master netting arrangement.

+ References

+ Details

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

- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A

+ Details

Name:	us-gaap_DerivativeNotionalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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_DerivativesFairValueLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum length of time over which the entity is hedging its exposure to the variability in future cash flows for forecasted transactions, excluding those forecasted transactions related to the payment of variable interest on existing financial instruments, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-SubTopic 30
-Topic 815
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480870/815-30-50-1

+ Details

Name:	us-gaap_MaximumLengthOfTimeHedgedInCashFlowHedge1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=txt_InterestRateSwapMaturingAugust2025ToAugust2029Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=txt_InterestRateSwapMaturingAugust2025ToAugust2030Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=txt_InterestRateSwapMaturingJune2025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: