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Share Capital - Schedule of Share Capital (Parenthetical) (Detail) € in Millions |  | 12 Months Ended
--- | --- | ---
Nov. 03, 2017 EUR (€) shares | Nov. 03, 2017 $ / shares | Dec. 31, 2017 EUR (€) shares
Disclosure of classes of share capital [line items] |  |  |
Share issued |  |  | 28,928,950
Proceeds from issue of ordinary shares | € |  |  | € 259
Ordinary shares [member] |  |  |
Disclosure of classes of share capital [line items] |  |  |
Share issued | 28,750,000 |  |
Share issued price per share | $ / shares |  | $ 11.00 |
Proceeds from issue of ordinary shares | € | € 259 |  |
Share issuance, arrangement fees | € | € 12 |  |
Treasury shares held |  |  | 38,597
Employees [member] | Common shares [member] |  |  |
Disclosure of classes of share capital [line items] |  |  |
Share issued |  |  | 125,000
Board members [member] | Common shares [member] |  |  |
Disclosure of classes of share capital [line items] |  |  |
Share issued |  |  | 53,950

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- Definition The amount of cost related to the issuance of shares. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2017-01-01 -Paragraph 106 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_106_d&doctype=Standard -URIDate 2017-03-09 + Details
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