Other reserves (Details) - EUR (€) € in Millions	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Other reserves.
Total share based payments reserve	€ 34	€ 41	€ 31
Total cash flow hedge reserve	€ 266	€ 31	€ 1,295

A component of equity representing the accumulated portion of gain (loss) on a hedging instrument that is determined to be an effective hedge for cash flow hedges. [Refer: Cash flow hedges [member]]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 78
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_78_e&doctype=Standard
-URIDate 2023-03-23

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 9
-IssueDate 2023-01-01
-Paragraph 6.5.11
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=9&code=ifrs-tx-2023-en-r&anchor=para_6.5.11&doctype=Standard
-URIDate 2023-03-23

Name:	ifrs-full_ReserveOfCashFlowHedges
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant