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Operating Segment Information - Summary of Revenue by Product Lines (Detail) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of products and services [line items]
Revenue	€ 5,237	€ 4,743	€ 5,153
Packaging rolled products [member]
Disclosure of products and services [line items]
Revenue	2,146	2,003	2,205
Automotive rolled products [member]
Disclosure of products and services [line items]
Revenue	483	319	275
Specialty and other thin-rolled products [member]
Disclosure of products and services [line items]
Revenue	176	160	262
Aerospace rolled products [member]
Disclosure of products and services [line items]
Revenue	760	795	861
Transportation, Industry and other rolled products [member]
Disclosure of products and services [line items]
Revenue	541	484	487
Automotive extruded products [member]
Disclosure of products and services [line items]
Revenue	614	537	544
Other extruded products [member]
Disclosure of products and services [line items]
Revenue	504	456	490
Other [member]
Disclosure of products and services [line items]
Revenue	€ 13	€ (11)	€ 29

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The income arising in the course of an entity's ordinary activities. Income is increases in economic benefits during the accounting period in the form of inflows or enhancements of assets or decreases of liabilities that result in an increase in equity, other than those relating to contributions from equity participants.

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