XML 150 R108.htm IDEA: XBRL DOCUMENT v3.19.1

Trade Receivables and Other - Summary of Ageing of Total Trade Receivables - Net (Detail) - EUR (€) € in Millions	Dec. 31, 2018	Dec. 31, 2017
Trade receivables [line items]
Trade receivables-net	€ 481	€ 306
Current [member]
Trade receivables [line items]
Trade receivables-net	453	286
Past Due 1 to 30 Days [member]
Trade receivables [line items]
Trade receivables-net	23	13
Past Due 31 to 60 Days [member]
Trade receivables [line items]
Trade receivables-net	2	2
Past Due 61 to 90 Days [member]
Trade receivables [line items]
Trade receivables-net	2	3
Past Due Greater Than 91 Days [member]
Trade receivables [line items]
Trade receivables-net	€ 1	€ 2

X

- Definition

Trade receivables [line items]

+ References

No definition available.

+ Details

Name:	cstm_TradeReceivablesLineItems
Namespace Prefix:	cstm_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount due from customers for goods and services sold.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 1
-IssueDate 2018-01-01
-Paragraph 78
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_78_b&doctype=Standard
-URIDate 2018-03-16

+ Details

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

X

- Details

Name:	ifrs-full_PastDueStatusAxis=ifrs-full_CurrentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_PastDueStatusAxis=cstm_PastDueOneToThirtyDaysMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_PastDueStatusAxis=ifrs-full_LaterThanOneMonthAndNotLaterThanTwoMonthsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_PastDueStatusAxis=ifrs-full_LaterThanTwoMonthsAndNotLaterThanThreeMonthsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_PastDueStatusAxis=ifrs-full_LaterThanThreeMonthsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: