XML 146 R109.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Property Plant and Equipment - Additional Information (Detail) - Muscle shoals [member] € in Millions | 12 Months Ended
--- | ---
Dec. 31, 2015 EUR (€)
Disclosure of detailed information about property, plant and equipment [line items] |
Discount rate applied to cash flows projection description | 11.00%
Growth rate for extrapolate the cash flows beyond the projection period | 0.00%
Recoverable value lower than the carrying value | € 400
Impairment charge | 400
Constellium Valais cash-generating units [member] |
Disclosure of detailed information about property, plant and equipment [line items] |
Impairment charge | € 49

X
- Definition Amount by which units recoverable lower than carrying amount. + References No definition available. + Details
Name: | cstm_AmountByWhichUnitsRecoverableLowerThanCarryingAmount
Namespace Prefix: | cstm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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 2017-01-01 -Paragraph 134 -Subparagraph d -Clause v -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2017-03-01&anchor=para_134_d_v&doctype=Standard -URIDate 2017-03-09 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2017-01-01 -Paragraph 134 -Subparagraph e -Clause v -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2017-03-01&anchor=para_134_e_v&doctype=Standard -URIDate 2017-03-09 + 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 2017-01-01 -Paragraph 134 -Subparagraph d -Clause iv -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2017-03-01&anchor=para_134_d_iv&doctype=Standard -URIDate 2017-03-09 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2017-01-01 -Paragraph 134 -Subparagraph e -Clause iv -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2017-03-01&anchor=para_134_e_iv&doctype=Standard -URIDate 2017-03-09 + 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 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 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 2017-01-01 -Paragraph 73 -Subparagraph e -Clause v -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=16&date=2017-03-01&anchor=para_73_e_v&doctype=Standard -URIDate 2017-03-09 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2017-01-01 -Paragraph 98 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_98_a&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_ImpairmentLossRecognisedInProfitOrLossPropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_BusinessCombinationsAxis=cstm_MuscleShoalsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_IndividualAssetsOrCashgeneratingUnitsWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesAxis=cstm_ConstelliumValaisCashGeneratingUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |