Basis of preparation (Details) - EUR (€) € in Millions |
12 Months Ended | ||
|---|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
Mar. 31, 2023 |
|
| Disclosure of Basis Of Preparation [Line Items] | |||
| Minimum undiscounted forecast period for assessing future taxable profits | 5 years | ||
| Threshold forecast period of recovery of tax losses | 5 years | ||
| Portion of property, plant and equipment in total assets (as a percent) | 23.90% | 19.70% | |
| Foreign exchange gain (loss) | € 171 | € 272 | € 111 |
| Operating profit | |||
| Disclosure of Basis Of Preparation [Line Items] | |||
| Foreign exchange gain (loss) | 146 | 110 | 247 |
| Financing costs | |||
| Disclosure of Basis Of Preparation [Line Items] | |||
| Foreign exchange gain (loss) | 1 | 173 | 135 |
| Income tax expense | |||
| Disclosure of Basis Of Preparation [Line Items] | |||
| Foreign exchange gain (loss) | € 24 | € 11 | € 1 |
| Land and buildings | Minimum [Member] | |||
| Disclosure of Basis Of Preparation [Line Items] | |||
| Lease term | 5 years | ||
| Land and buildings | Maximum [Member] | |||
| Disclosure of Basis Of Preparation [Line Items] | |||
| Lease term | 10 years | ||