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Currency Gains / (Losses) - Summary of Currency Gains and Losses Included in Income from Operations (Detail) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Analysis of income and expense [line items]
Currency gains /(losses)	€ (6)	€ 1	€ (37)
Realized exchange losses on foreign currency derivatives-net	(15)	(46)	(37)
Unrealized gains /(losses) on foreign currency derivatives-net	17	40	(10)
Exchanges (losses)/gains from the remeasurement of monetary assets and liabilities-net	(8)	7	10
Revenue [member]
Analysis of income and expense [line items]
Currency gains /(losses)	2
Cost of sales.
Analysis of income and expense [line items]
Currency gains /(losses)	(4)	4	13
Other gains / (losses - net [member]
Analysis of income and expense [line items]
Currency gains /(losses)	€ (4)	€ (3)	€ (50)

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The amount of exchange differences recognised in profit or loss that arise from foreign currency transactions, excluding those arising on financial instruments measured at fair value through profit or loss in accordance with IFRS 9. [Refer: At fair value [member]; Financial instruments, class [member]]

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