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Related Parties - Summary of Key Management Personnel Compensation (Detail) - EUR (€) € in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of transactions between related parties [abstract]
Short term employee benefits	€ 9	€ 8	€ 10
Directors' fees	1	1	1
Share-based compensation	6	4	2
Post-employments benefits	0	0	0
Termination benefits		1	1
Employer social contribution	1	1	2
Total	€ 17	€ 15	€ 16

X

- Definition

Key management personnel compensation employer social contribution.

+ References

No definition available.

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X

- Definition

The amount of remuneration paid or payable to the entity's directors.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
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-IssueDate 2018-01-01
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- References

No definition available.

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- Definition

The amount of compensation to key management personnel. [Refer: Key management personnel of entity or parent [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
-IssueDate 2018-01-01
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- Definition

The amount of compensation to key management personnel in the form of post-employment benefits. [Refer: Key management personnel of entity or parent [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
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- Definition

The amount of compensation to key management personnel in the form of share-based payments. [Refer: Key management personnel of entity or parent [member]]

+ References

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-Name IAS
-Number 24
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- Definition

The amount of compensation to key management personnel in the form of short-term employee benefits. [Refer: Key management personnel of entity or parent [member]]

+ References

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- Definition

The amount of compensation to key management personnel in the form of termination benefits. [Refer: Termination benefits expense; Key management personnel of entity or parent [member]]

+ References

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