XML 550 R139.htm IDEA: XBRL DOCUMENT
v3.22.0.1

NON-CASH INVESTING AND FINANCING TRANSACTIONS (Details) - EUR (€) € in Millions | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Disclosure of cash flow statement [Abstract] |  |  |
Property, plant and equipment acquired by finance lease | € 18 | € 66 | € 75
Fair value of vested PSUs and RSUs | € 15 | € 14 | € 8

X
- Definition Additions through noncash finance lease, property, plant and equipment. + References No definition available. + Details
Name: | cstm_AdditionsThroughNoncashFinanceLeasePropertyPlantAndEquipment
Namespace Prefix: | cstm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Disclosure of cash flow statement + References No definition available. + Details
Name: | cstm_DisclosureofcashflowstatementAbstract
Namespace Prefix: | cstm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of performance stock units and restricted stock units vested. + References No definition available. + Details
Name: | cstm_FairValueOfPerformanceStockUnitsAndRestrictedStockUnitsVested
Namespace Prefix: | cstm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration