Basis of preparation and significant accounting policies - Reconciliation net result under IFRS-EU and IFRS-IASB (Details) - EUR (€) € in Millions	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021
Disclosure Of Reconciliation Net Result Eu Ifrs And Iasb Ifrs [abstract]
In accordance with IFRS-EU (attributable to shareholders of parent)	€ 1,606	€ 2,464
Adjustment of the EU IAS 39 carve-out	8,594	956
Tax effect of the adjustment	(2,456)	(260)
Effect of adjustment after tax	6,139	697
In accordance with IFRS-IASB (attributable to the equityholdersshareholders of the parent)	€ 7,745	€ 3,161

The profit (loss) from continuing and discontinued operations attributable to owners of the parent. [Refer: Profit (loss)]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2021-01-01
-Paragraph 81B
-Subparagraph a
-Clause ii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_81B_a_ii&doctype=Standard
-URIDate 2021-03-24

Name:	ifrs-full_ProfitLossAttributableToOwnersOfParent
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration