XML 88 R80.htm IDEA: XBRL DOCUMENT v3.20.2

PROPERTY, PLANT AND EQUIPMENT - Additional Information (Details) - EUR (€)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Disclosure of detailed information about property, plant and equipment [abstract]
Expense related to short-term leases, low value asset leases and variable lease still recognized as operating expenses	€ 6,000,000	€ 7,000,000
Impairment charges related to cash-generating units	€ 0
Average percentage of operating level of plants	50.00%
Impairment loss recognised in profit or loss, property, plant and equipment	€ 5,000,000

X

- Definition

Average Percentage Of Operating Capacity Of Plants

+ References

No definition available.

+ Details

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

X

- Definition

Expense Relating To Short-term Leases, Leases Of Low-value Assets And Variable Lease Payments For Which Recognition Exemption Has Been Used

+ References

No definition available.

+ Details

Name:	cstm_ExpenseRelatingToShorttermLeasesLeasesOfLowvalueAssetsAndVariableLeasePaymentsForWhichRecognitionExemptionHasBeenUsed
Namespace Prefix:	cstm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- References

No definition available.

+ Details

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

X

- Definition

The amount recognised as a reduction of the carrying amount of an asset or cash-generating unit to its recoverable amount. [Refer: Carrying amount [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2019-01-01
-Paragraph 130
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=36&code=ifrs-tx-2019-en-r&anchor=para_130_b&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2019-01-01
-Paragraph 130
-Subparagraph d
-Clause ii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=36&code=ifrs-tx-2019-en-r&anchor=para_130_d_ii&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_ImpairmentLoss
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The amount of impairment loss recognised in profit or loss for property, plant and equipment. [Refer: Impairment loss recognised in profit or loss; Property, plant and equipment]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 16
-IssueDate 2019-01-01
-Paragraph 73
-Subparagraph e
-Clause v
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2019-en-r&anchor=para_73_e_v&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 98
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_98_a&doctype=Standard
-URIDate 2019-03-27

+ Details

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