XML 80 R65.htm IDEA: XBRL DOCUMENT v3.25.1

FINANCIAL INSTRUMENTS - Schedule of notional amounts of outstanding derivatives (Details) $ in Millions	Mar. 31, 2025 USD ($)
Less than 1 year | USD | Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	$ 373
Less than 1 year | USD | Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	75
Less than 1 year | CHF | Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	56
Less than 1 year | CHF | Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	120
Less than 1 year | CZK | Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	6
Less than 1 year | CZK | Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	71
Less than 1 year | Other currencies | Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	11
Less than 1 year | Other currencies | Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	8
Less than 1 year | Metal | Derivatives that do not qualify for hedge accounting
Derivatives, Fair Value [Line Items]
Derivative, notional amount	400
Less than 1 year | Natural gas | Derivatives that do not qualify for hedge accounting
Derivatives, Fair Value [Line Items]
Derivative, notional amount	9
Over 1 year | USD | Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	449
Over 1 year | USD | Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	9
Over 1 year | CHF | Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	6
Over 1 year | CHF | Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	25
Over 1 year | CZK | Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	0
Over 1 year | CZK | Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	34
Over 1 year | Other currencies | Sold currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	1
Over 1 year | Other currencies | Purchased currencies
Derivatives, Fair Value [Line Items]
Derivative, notional amount	0
Over 1 year | Metal | Derivatives that do not qualify for hedge accounting
Derivatives, Fair Value [Line Items]
Derivative, notional amount	43
Over 1 year | Natural gas | Derivatives that do not qualify for hedge accounting
Derivatives, Fair Value [Line Items]
Derivative, notional amount	$ 18

X

- 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

X

- 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

X

- Details

Name:	cstm_MaturityAxis=cstm_NotLaterThanOneYearMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

Name:	us-gaap_PositionAxis=us-gaap_ShortMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PositionAxis=us-gaap_LongMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

Name:	cstm_MaturityAxis=cstm_LaterThanOneYearMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: