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SHARE CAPITAL (Tables) | 12 Months Ended
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Dec. 31, 2020
Disclosure of share capital, reserves and other equity interest [Abstract] |
Schedule of Share Capital |
|  |  |  | (in millions of Euros)
|  | Number of shares |  | Share capital |  | Share premium
At January 1, 2020 |  | 137,867,418 |  |  | 3 |  |  | 420 |
New shares issued (A) |  | 2,095,254 |  |  | — |  |  | — |
At December 31, 2020 |  | 139,962,672 |  |  | 3 |  |  | 420 |
(A)Constellium SE issued and delivered 2,095,254 ordinary shares to certain employees and directors related to share-based compensation plans.

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- Definition The disclosure of issued capital. [Refer: Issued capital] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 10 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_10_e&doctype=Standard -URIDate 2020-01-01 + Details
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