DESCRIPTION OF THE PLAN AND INVESTMENT PROGRAM (Details) - EBP 003	12 Months Ended
Dec. 31, 2025 USD ($) loan	Dec. 31, 2024 USD ($)
EBP, Description of Plan [Line Items]
Participant contribution, pretax, minimum percentage (as a percent)	1.00%
Participant contribution, pretax, maximum, percentage (as a percent)	50.00%
Participant contribution, after tax, minimum percentage (as a percent)	1.00%
Participant contribution, after tax, maximum, percentage (as a percent)	10.00%
Participant contribution, pretax and after tax, maximum percentage (as a percent)	50.00%
Participant contribution, automatic deferral rate (as a percent)	6.00%
Participant contribution, automatic deferral rate, annual increase (as a percent)	1.00%
Employer contribution vesting service period	3 years
Note receivable from participant, maximum borrowing percentage (as a percent)	50.00%
Note receivable from participant, maximum borrowing amount (as a percent)	$ 50,000
Note receivable from participant, minimum borrowing amount	$ 1,000
Note receivable from participant, general loan, maximum borrowing term	5 years
Note receivable from participant, maximum number of outstanding loans per participant \| loan	2
Forfeited nonvested account	$ 897,000	$ 968,000
Forfeited nonvested account, decrease from employer contribution	$ 3,700,000
Tranche One \| Employee Group One
EBP, Description of Plan [Line Items]
Employer contribution, matching percentage (as a percent)	100.00%
Employer contribution, participant compensation matched (as a percent)	1.00%
Tranche One \| Employee Group, Two
EBP, Description of Plan [Line Items]
Employer contribution, matching percentage (as a percent)	100.00%
Employer contribution, participant compensation matched (as a percent)	3.00%
Tranche Two \| Employee Group One
EBP, Description of Plan [Line Items]
Employer contribution, matching percentage (as a percent)	50.00%
Employer contribution, participant compensation matched (as a percent)	5.00%
Tranche Two \| Employee Group, Two
EBP, Description of Plan [Line Items]
Employer contribution, matching percentage (as a percent)	50.00%
Employer contribution, participant compensation matched (as a percent)	3.00%

EBP, Employer Contribution Vesting Service Period

No definition available.

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Period Type:	duration

- Definition

EBP, Note Receivable From Participant, General Loan, Maximum Borrowing Term

+ References

No definition available.

+ Details

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Namespace Prefix:	itw_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Note Receivable From Participant, Maximum Number Of Outstanding Loans Per Participant

+ References

No definition available.

+ Details

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

- Definition

EBP, Participant Contribution, Aftertax, Maximum Annual Compensation to Total Compensation, Percentage

+ References

No definition available.

+ Details

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Namespace Prefix:	itw_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Participant Contribution, Aftertax, Minimum Annual Compensation to Total Compensation, Percentage

+ References

No definition available.

+ Details

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- Definition

EBP, Participant Contribution, Automatic, Deferral Rate, Annual Increase

+ References

No definition available.

+ Details

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Namespace Prefix:	itw_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Participant Contribution, Pretax and Aftertax, Maximum Annual Compensation to Total Compensation, Percentage

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Participant Contribution, Pretax, Minimum Annual Compensation to Total Compensation, Percentage

+ References

No definition available.

+ Details

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Namespace Prefix:	itw_
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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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of employer matching contribution on eligible participant contribution to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
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Balance Type:	na
Period Type:	duration

- Definition

Percentage of participant compensation eligible for employer matching contribution for participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of plan asset, in forfeited nonvested account, no longer allocated to participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of decrease in forfeited nonvested account of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) from employer contribution.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (j)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-04(5)(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of maximum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow.

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of maximum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow to total participant account balance.

+ References

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of minimum account balance that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) can borrow.

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of eligible compensation contributed for participant automatically enrolled in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of maximum pretax annual compensation that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)), is permitted to contribute to total pretax annual compensation.

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
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Period Type:	duration

- Details

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- Details

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- Details

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