Disposal Group, Including Discontinued Operation, Combined Annual Revenues

No definition available.

Name:	itw_DisposalGroupIncludingDiscontinuedOperationCombinedAnnualRevenues
Namespace Prefix:	itw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Disposal Group, Including Discontinued Operation, Revenue, Potential Divestitures

+ References

No definition available.

+ Details

Name:	itw_DisposalGroupIncludingDiscontinuedOperationRevenuePotentialDivestitures
Namespace Prefix:	itw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Disposal Group, Including Discontinued Operations, Number Of Businesses Divested

+ References

No definition available.

+ Details

Name:	itw_DisposalGroupIncludingDiscontinuedOperationsNumberOfBusinessesDivested
Namespace Prefix:	itw_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Disposal Group, Including Discontinued Operations, Number Of Businesses To Be Divested

+ References

No definition available.

+ Details

Name:	itw_DisposalGroupIncludingDiscontinuedOperationsNumberOfBusinessesToBeDivested
Namespace Prefix:	itw_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of revenue attributable to disposal group, including, but not limited to, discontinued operation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5B
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI https://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760

+ Details

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

- Definition

Amount of gain (loss) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1B
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=109239629&loc=SL4582445-111684

+ Details

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

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

- Definition

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3179-108585

+ Details

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

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=itw_A2019DivestituresPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=itw_A2022DivestituresPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

Divestitures - Narrative (Details) - Disposal group, held-for-sale $ in Millions		3 Months Ended				9 Months Ended	12 Months Ended
	Oct. 03, 2022 USD ($) business	Dec. 31, 2022 USD ($)	Sep. 30, 2022 business	Jun. 30, 2022 business	Dec. 31, 2019 business	Sep. 30, 2022 USD ($) business	Dec. 31, 2021 USD ($)
2019 Divestitures Plan
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Divestiture of businesses, annual revenues \| $						$ 1,000
Number of businesses divested \| business					3
2022 Divestitures Plan
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Combined annual revenues for businesses to be sold \| $						$ 500
Number of businesses to be divested \| business			2	2		2
Operating revenue \| $							$ 115
2022 Divestitures Plan \| Forecast
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of business \| $		$ 156
2022 Divestitures Plan \| Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of business \| $	$ 220
2022 Divestitures Plan \| Polymers & Fluids
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of businesses to be divested \| business				1
2022 Divestitures Plan \| Polymers & Fluids \| Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of businesses divested \| business	1
2022 Divestitures Plan \| Food Equipment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of businesses to be divested \| business				1