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Expenses by Nature - Summary of Information about Expenses by Nature (Detail) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of detailed information about expenses by nature [abstract]
Raw materials and consumables used	€ (3,197)	€ (2,792)	€ (3,176)
Employee benefit expenses	(924)	(897)	(887)
Energy costs	(138)	(140)	(168)
Sub-contractors	(99)	(108)	(86)
Freight out costs	(124)	(128)	(130)
Professional fees	(77)	(85)	(75)
Operating lease expenses	(27)	(27)	(29)
Depreciation and amortization	(171)	(155)	(140)
Impairment			(457)
Other operating expenses	(229)	(186)	(300)
Other gains / (losses)-net	70	21	(131)
Total Operating expenses	€ (4,916)	€ (4,497)	€ (5,579)

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Disclosure of detailed information about expenses by nature.

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The amount of depreciation and amortisation expense. Depreciation and amortisation are the systematic allocations of depreciable amounts of assets over their useful lives.

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The expense of all forms of consideration given by an entity in exchange for a service rendered by employees or for the termination of employment.

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The amount of expense arising from the consumption of energy.

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The amount of impairment loss or reversal of impairment loss recognised in profit or loss. [Refer: Impairment loss recognised in profit or loss; Reversal of impairment loss recognised in profit or loss]

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The amount of miscellaneous other operating expenses. [Refer: Other operating income (expense)]

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The amount of raw materials and consumables used in the production process or in the rendering of services. [Refer: Current raw materials]

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The amount of expense arising from transportation services.

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