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FINANCIAL RISK MANAGEMENT - Mark-to-market Movements Recognized in Other Gains (Losses) - Net (Details) - Commodity price risk - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of nature and extent of risks arising from financial instruments [line items]
Realized (losses) / gains on commodity derivatives - net	€ (31)	€ (56)	€ 7
Unrealized gains / (losses) on commodity derivatives - net	€ 25	€ 31	€ (83)

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Realized gains losses on commodity derivatives net.

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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.

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