Financial instruments - Fair values and risk management - Guarantees (Details) - EUR (€) € in Millions	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021
Subsidiaries \| Letters of guarantee
Disclosure of transactions between related parties [line items]
Letters of guarantee	€ 4,120	€ 5,090	€ 5,430

The amount that best represents the maximum exposure to credit risk without taking into account any collateral held or other credit enhancements (for example, netting agreements that do not qualify for offset in accordance with IAS 32). [Refer: Credit risk [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2022-03-24
-Paragraph 35K
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2022-en-r&anchor=para_35K_a&doctype=Standard
-URIDate 2022-03-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2023-01-01
-Name IFRS
-Number 7
-IssueDate 2022-03-24
-Paragraph 36
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_36_a&doctype=Standard&book=b
-URIDate 2022-03-24

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