Income from operations - Text details (Detail) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Income from operations [Line items]
Impairment of goodwill	€ 9	€ 1
Land and buildings [Member] \| United States [Member]
Income from operations [Line items]
Income on disposal of fixed assets	€ 59

The amount of impairment loss recognised in profit or loss for goodwill. [Refer: Impairment loss recognised in profit or loss; Goodwill]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2017-01-01
-Paragraph B67
-Subparagraph d
-Clause v
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=3&date=2017-03-01&anchor=para_B67_d_v&doctype=Appendix&seq=2
-URIDate 2017-03-09

Name:	ifrs-full_ImpairmentLossRecognisedInProfitOrLossGoodwill
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration