Impairment losses and goodwill - Goodwill - Net book value (Details) - EUR (€) € in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill [abstract]
Net book value	€ 27,644	€ 27,174	€ 26,911

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]]

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant