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Financial Instruments - Summary of Derivatives Measured at Fair Value (Detail) - EUR (€) € in Millions | Dec. 31, 2018 | Dec. 31, 2017
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Disclosure of financial instruments measured at fair value [line items] |  |
Other financial assets-derivatives | € 30 | € 96
Other financial liabilities-derivatives | 89 | 66
Level 1 of fair value hierarchy [member] |  |
Disclosure of financial instruments measured at fair value [line items] |  |
Other financial assets-derivatives | 9 | 46
Other financial liabilities-derivatives | 50 | 6
Level 2 of fair value hierarchy [member] |  |
Disclosure of financial instruments measured at fair value [line items] |  |
Other financial assets-derivatives | 21 | 50
Other financial liabilities-derivatives | € 39 | € 60

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- Definition Disclosure of financial instruments measured at fair value. + References No definition available. + Details
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- Definition The amount of financial assets classified as derivative instruments. [Refer: Financial assets; Derivatives [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2018-01-01 -Paragraph 55 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_55&doctype=Standard -URIDate 2018-03-16 + Details
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- Definition The amount of financial liabilities classified as derivative instruments. [Refer: Financial assets; Derivatives [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2018-01-01 -Paragraph 55 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_55&doctype=Standard -URIDate 2018-03-16 + Details
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