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SHARE OF INCOME / (LOSS) OF JOINT-VENTURES - Narrative (Details)	Jan. 10, 2019
Constellium Bowling Green LLC
Disclosure of investments accounted for using equity method [line items]
Percentage of voting equity interest acquired	49.00%

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- Definition

Disclosure Of Investments Accounted For Using Equity Method [line items]

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- Definition

The percentage of voting equity interests acquired in a business combination. [Refer: Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2020-01-01
-Paragraph B64
-Subparagraph c
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-URIDate 2020-01-01

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