XML 98 R90.htm IDEA: XBRL DOCUMENT v3.19.2

Property Plant and Equipment - Summary of Property Plant and Equipment Right of Use Assets (Parenthetical) (Detail) - IFRS 16 [member] € in Millions	Jan. 01, 2019 EUR (€)
Finance lease [member]
Disclosure of detailed information about property, plant and equipment [line items]
Right-of-use asset	€ 77
Operating lease [member]
Disclosure of detailed information about property, plant and equipment [line items]
Right-of-use asset	€ 102

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

X

- Definition

The amount of assets that represent a lessee's right to use an underlying asset for the lease term. Underlying asset is an asset that is the subject of a lease, for which the right to use that asset has been provided by a lessor to a lessee.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2019-01-01
-Name IFRS
-Number 16
-IssueDate 2018-01-01
-Paragraph 53
-Subparagraph j
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=16&date=2018-03-01&anchor=para_53_j&doctype=Standard
-URIDate 2018-03-16

+ Details

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

X

- Details

Name:	ifrs-full_ClassesOfAssetsAxis=cstm_FinanceLeaseAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_RetrospectiveApplicationAndRetrospectiveRestatementAxis=cstm_IFRS16Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfAssetsAxis=cstm_OperatingLeaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: