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Investments Accounted for Under Equity Method - Additional Information (Detail) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share of profit (loss) of associates and joint ventures accounted for using equity method [abstract]
Cumulative share of losses of joint-ventures in excess of initial investment	€ 49
Share of losses of joint-ventures in excess of initial investment	€ 33	€ 29	€ 14

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- Definition

Cumulative share of profit (loss) of joint ventures accounted for using equity method.

+ References

No definition available.

+ Details

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- References

No definition available.

+ Details

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- Definition

The entity's share of the profit (loss) of joint ventures accounted for using the equity method. [Refer: Investments accounted for using equity method; Joint ventures [member]; Profit (loss)]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2018-01-01
-Paragraph 85
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_85&doctype=Standard
-URIDate 2018-03-16

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