XML 513 R102.htm IDEA: XBRL DOCUMENT v3.22.0.1

INTANGIBLE ASSETS AND GOODWILL - Narrative (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Goodwill	€ 451,000,000	€ 417,000,000	€ 455,000,000
P&ARP
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Goodwill	444,000,000
Carrying value	1,500,000,000
Recoverable value	2,000,000,000
Goodwill impairment	€ 0
Cash flow rates	40.00%
P&ARP | Bottom of range
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Discount rate to estimate normative cash flows	9.00%
P&ARP | Top of range
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Long term growth rate used to estimate normative cash flow	1.50%
A&T
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Goodwill	€ 5,000,000
Long term growth rate used to estimate normative cash flow		1.50%
Discount rate to estimate normative cash flows		9.00%
AS&I
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Goodwill	€ 2,000,000
Discount rate to estimate normative cash flows		9.00%

X

- Definition

Carrying Amount Of Asset Or Cash-generating Unit

+ References

No definition available.

+ Details

Name:	cstm_CarryingAmountOfAssetOrCashGeneratingUnit
Namespace Prefix:	cstm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Percentage Decrease In Cash Flows In Determining Amount By Which Units Recoverable Amount Exceeds Its Carrying Value

+ References

No definition available.

+ Details

Name:	cstm_PercentageDecreaseInCashFlowsInDeterminingAmountByWhichUnitsRecoverableAmountExceedsItsCarryingValue
Namespace Prefix:	cstm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The discount rate applied to cash flow projections for a cash-generating unit (group of units). [Refer: Cash-generating units [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2021-01-01
-Paragraph 134
-Subparagraph d
-Clause v
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=36&code=ifrs-tx-2021-en-r&anchor=para_134_d_v&doctype=Standard
-URIDate 2021-03-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2021-01-01
-Paragraph 134
-Subparagraph e
-Clause v
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=36&code=ifrs-tx-2021-en-r&anchor=para_134_e_v&doctype=Standard
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_DescriptionOfDiscountRatesAppliedToCashFlowProjections
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The growth rate used to extrapolate cash flow projections beyond the period covered by the most recent budgets/forecasts for a cash-generating unit (group of units). [Refer: Cash-generating units [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2021-01-01
-Paragraph 134
-Subparagraph d
-Clause iv
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=36&code=ifrs-tx-2021-en-r&anchor=para_134_d_iv&doctype=Standard
-URIDate 2021-03-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2021-01-01
-Paragraph 134
-Subparagraph e
-Clause iv
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=36&code=ifrs-tx-2021-en-r&anchor=para_134_e_iv&doctype=Standard
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_DescriptionOfGrowthRateUsedToExtrapolateCashFlowProjections
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- 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

Name:	ifrs-full_DisclosureOfReconciliationOfChangesInIntangibleAssetsAndGoodwillLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount of assets representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognised. [Refer: Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B67
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B67_d&doctype=Appendix&subtype=B
-URIDate 2021-03-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2021-01-01
-Paragraph 134
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=36&code=ifrs-tx-2021-en-r&anchor=para_134_a&doctype=Standard
-URIDate 2021-03-24

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2021-01-01
-Paragraph 135
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=36&code=ifrs-tx-2021-en-r&anchor=para_135_a&doctype=Standard
-URIDate 2021-03-24

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2021-01-01
-Paragraph 54
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_54_c&doctype=Standard
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_Goodwill
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The amount of impairment loss recognised in profit or loss for goodwill. [Refer: Impairment loss recognised in profit or loss; Goodwill]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2021-01-01
-Paragraph B67
-Subparagraph d
-Clause v
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2021-en-r&anchor=para_B67_d_v&doctype=Appendix&subtype=B
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_ImpairmentLossRecognisedInProfitOrLossGoodwill
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The higher of an asset’s (or cash-generating unit’s) fair value less costs of disposal and its value in use. [Refer: Cash-generating units [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2021-01-01
-Paragraph 130
-Subparagraph e
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=36&code=ifrs-tx-2021-en-r&anchor=para_130_e&doctype=Standard
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_RecoverableAmountOfAssetOrCashgeneratingUnit
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	ifrs-full_SegmentsAxis=cstm_PackagingAndAutomotiveRolledProductsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SegmentsAxis=cstm_AerospaceAndTransportationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SegmentsAxis=cstm_AutomotiveStructuresAndIndustryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: