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Summary of Significant Accounting Policies - Opening Balance Sheet Reclassification (IFRS 15 Standard) (Detail) - EUR (€) € in Millions | Jun. 30, 2018 | Jan. 01, 2018 | Dec. 31, 2017
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Disclosure of reclassification of financial assets [line items] |  |  |
Trade receivables and other |  | € 483 | € 467
Trade payables and other |  | (1,023) | (984)
Provisions | € (136) | (130) | € (153)
Contracts liabilities reclassification [member] |  |  |
Disclosure of reclassification of financial assets [line items] |  |  |
Trade receivables and other |  | 16 |
Trade payables and other |  | (39) |
Provisions |  | € 23 |

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- Definition The amount of trade receivables and other receivables. [Refer: Trade receivables; Other receivables] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2017-01-01 -Paragraph 54 -Subparagraph h -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_54_h&doctype=Standard -URIDate 2017-03-09 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2017-01-01 -Paragraph 78 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_78_b&doctype=Standard -URIDate 2017-03-09 + Details
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