Intangible assets (Details 4) - EUR (€) € in Millions	Dec. 31, 2018	Dec. 31, 2017
Goodwill		€ 1,204
Gas And Power [Member]
Goodwill		932
Gas And Power [Member] \| Domestic Gas Market [Member]
Goodwill	835	835
Gas And Power [Member] \| European Gas Market [Member]
Goodwill	€ 142	€ 97

The amount of assets representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognised. [Refer: Business combinations [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2018-01-01
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-Subparagraph d
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-URIDate 2018-03-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
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-URIDate 2018-03-16

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
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-Subparagraph a
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant