CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Statement of Comprehensive Income [Abstract] | ||||
| Net income | $ 119 | $ 88 | $ 463 | $ 162 |
| Other comprehensive (loss) / income | ||||
| Net change in post-employment benefit obligations | (3) | (6) | (12) | (9) |
| Income tax on net change in post-employment benefit obligations | 1 | 1 | 2 | 1 |
| Net change in cash flow hedges | (3) | (3) | (14) | 34 |
| Income tax on cash flow hedges | 1 | 1 | 4 | (9) |
| Currency translation adjustments | (2) | 2 | (8) | 17 |
| Other comprehensive (loss) / income | (6) | (5) | (28) | 34 |
| Total comprehensive (loss) / income | 113 | 83 | 435 | 196 |
| Attributable to: | ||||
| Equity holders of Constellium SE | 111 | 83 | 434 | 194 |
| Non-controlling interests | $ 2 | $ 0 | $ 1 | $ 2 |
| X | ||||||||||
- Definition Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income (loss) and other comprehensive income (loss), attributable to noncontrolling interests. Excludes changes in equity resulting from investments by owners and distributions to owners. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- References No definition available.
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| X | ||||||||||
- Definition Amount, before tax and after reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount, after reclassification, of tax expense (benefit) for gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount after tax and reclassification adjustments of other comprehensive income (loss). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- References No definition available.
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| X | ||||||||||
- Definition Amount, before tax, after reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount, after reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income of defined benefit plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- References No definition available.
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