The amount of outstanding funds that the entity is obligated to repay.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
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-URIDate 2024-03-27

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Period Type:	instant

- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

The amount of current borrowings. [Refer: Borrowings]

+ References

+ Details

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

- Definition

The amount of undrawn borrowing facilities that may be available for future operating activities and to settle capital commitments. [Refer: Capital commitments]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 7
-IssueDate 2024-01-01
-Paragraph 50
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-URIDate 2024-03-27

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Balance Type:	credit
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- Definition

Borrowings, Maximum Capacity

+ References

No definition available.

+ Details

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Namespace Prefix:	mt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Definition

Line Of Credit Facility, Maximum Borrowing Capacity1

+ References

No definition available.

+ Details

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

- Details

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- Details

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SHORT-TERM AND LONG-TERM DEBT - Short-term debt narrative (Details) $ in Millions, € in Billions	Jun. 30, 2025 USD ($)	Jun. 30, 2025 EUR (€)	Dec. 31, 2024 USD ($)	Dec. 12, 2023 USD ($)
Disclosure of detailed information about borrowings [line items]
Short-term bank loans and other credit facilities	$ 1,462		$ 1,016
Short-term bilateral credit facility
Disclosure of detailed information about borrowings [line items]
Undrawn borrowing facilities	400
Commercial paper
Disclosure of detailed information about borrowings [line items]
Borrowings, maximum capacity \| €		€ 1.5
Short-term bank loans and other credit facilities	963
Receivables facility agreement \| Calvert
Disclosure of detailed information about borrowings [line items]
Line of credit facility, maximum borrowing capacity				$ 300
Borrowings outstanding	225
378 and 480 million tax-exempt bonds
Disclosure of detailed information about borrowings [line items]
Borrowings outstanding	$ 843