Financial instruments - Fair values and risk management - Fair value transfers (Details) - EUR (€) € in Millions	12 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Financial instruments - Fair values and risk management
Transfer from level 1 to level 2 (assets)	€ 0	€ 0	€ 0
Transfer from level 2 to level 1 (assets)	0	0	0
Transfer from level 1 to level 2 (liabilities)	0	0	0
Transfer from level 2 to level 1 (liabilities)	0	0	0
Transfer into Level 3 (assets)	0	0	0
Transfer out of Level3 (assets)	0	0	0
Transfer into Level 3 (liabilities)	0	0	0
Transfer out of Level3 (liabilities)	€ 0	€ 0	€ 0

No definition available.

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- Definition

The amount of transfers of assets into Level 3 of the fair value hierarchy. [Refer: Level 3 of fair value hierarchy [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 13
-IssueDate 2020-01-01
-Paragraph 93
-Subparagraph e
-Clause iv
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2020-en-r&anchor=para_93_e_iv&doctype=Standard
-URIDate 2020-01-01

+ Details

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- Definition

The amount of transfers of liabilities into Level 3 of the fair value hierarchy. [Refer: Level 3 of fair value hierarchy [member]]

+ References

+ Details

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- Definition

The amount of transfers out of Level 1 and into Level 2 of the fair value hierarchy of assets held at the end of the reporting period. [Refer: Level 1 of fair value hierarchy [member]; Level 2 of fair value hierarchy [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 13
-IssueDate 2020-01-01
-Paragraph 93
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2020-en-r&anchor=para_93_c&doctype=Standard
-URIDate 2020-01-01

+ Details

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- Definition

The amount of transfers out of Level 1 and into Level 2 of the fair value hierarchy of liabilities held at the end of the reporting period. [Refer: Level 1 of fair value hierarchy [member]; Level 2 of fair value hierarchy [member]]

+ References

+ Details

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- Definition

The amount of transfers out of Level 2 and into Level 1 of the fair value hierarchy of assets held at the end of the reporting period. [Refer: Level 1 of fair value hierarchy [member]; Level 2 of fair value hierarchy [member]]

+ References

+ Details

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- Definition

The amount of transfers out of Level 2 and into Level 1 of the fair value hierarchy of liabilities held at the end of the reporting period. [Refer: Level 1 of fair value hierarchy [member]; Level 2 of fair value hierarchy [member]]

+ References

+ Details

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- Definition

The amount of transfers of assets out of Level 3 of the fair value hierarchy. [Refer: Level 3 of fair value hierarchy [member]]

+ References

+ Details

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- Definition

The amount of transfers of liabilities out of Level 3 of the fair value hierarchy. [Refer: Level 3 of fair value hierarchy [member]]

+ References

+ Details

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