XML 562 R133.htm IDEA: XBRL DOCUMENT v3.20.4

PENSIONS AND OTHER POST-EMPLOYMENT BENEFIT OBLIGATIONS - Amounts Recognized in the Consolidated Statement of Financial Position (Details) - EUR (€) € in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of net defined benefit liability (asset) [line items]
Present value of funded obligation	€ 772	€ 768
Fair value of plan assets	(458)	(445)
Deficit of funded plans	314	323
Present value of unfunded obligation	350	347
Net liability arising from defined benefit obligation	664	670
Pension Benefits
Disclosure of net defined benefit liability (asset) [line items]
Present value of funded obligation	772	768
Fair value of plan assets	(458)	(445)
Deficit of funded plans	314	323
Present value of unfunded obligation	134	127
Net liability arising from defined benefit obligation	448	450
Other Benefits
Disclosure of net defined benefit liability (asset) [line items]
Present value of funded obligation	0	0
Fair value of plan assets	0	0
Deficit of funded plans	0	0
Present value of unfunded obligation	216	220
Net liability arising from defined benefit obligation	€ 216	€ 220

X

- Definition

Present value of unfunded obligation.

+ References

No definition available.

+ Details

Name:	cstm_PresentValueOfUnfundedObligation
Namespace Prefix:	cstm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The present value, without deducting any plan assets, of expected future payments required to settle the obligation resulting from employee service in the current and prior periods. [Refer: Plan assets, at fair value]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2020-01-01
-Paragraph 57
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_57_a&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_DefinedBenefitObligationAtPresentValue
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

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

+ References

No definition available.

+ Details

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

X

- Definition

The amount of non-current net defined benefit liability. [Refer: Net defined benefit liability]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 55
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_55&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_NoncurrentRecognisedLiabilitiesDefinedBenefitPlan
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The fair value of defined benefit plan assets. Plan assets comprise assets held by a long-term employee benefit fund and qualifying insurance policies. [Refer: At fair value [member]]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2020-01-01
-Paragraph 57
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_57_a&doctype=Standard
-URIDate 2020-01-01

+ Details

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

X

- Definition

The fair value of any plan assets, less the present value of the defined benefit obligation. [Refer: Plan assets [member]]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2020-01-01
-Paragraph 57
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_57_a&doctype=Standard
-URIDate 2020-01-01

+ Details

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

X

- Details

Name:	ifrs-full_DefinedBenefitPlansAxis=ifrs-full_PensionDefinedBenefitPlansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_DefinedBenefitPlansAxis=cstm_OtherBenefitPlansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: