v3.26.1
Financial instruments - Fair value and risk management - Summary of derivative financial instruments (Details) - EUR (€)
€ in Millions
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial assets € 2,226.3 € 109.8 € 352.8
Derivative financial liabilities (150.1) (227.2) (182.1)
Designated as continuing cash flow hedges      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial liabilities (150.1) (227.2) (182.1)
Designated as continuing cash flow hedges      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial assets 2,226.3 109.8 325.9
Where hedge accounting is no longer applied      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial assets     26.9
Less than one year      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial assets 2,133.9 94.4 349.5
Derivative financial liabilities (142.3) (224.7) (178.8)
Less than one year | Designated as continuing cash flow hedges      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial liabilities (142.3) (224.7) (178.8)
Less than one year | Designated as continuing cash flow hedges      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial assets 2,133.9 94.4 322.6
Less than one year | Where hedge accounting is no longer applied      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial assets     26.9
More than one year      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial assets 92.4 15.4 3.3
Derivative financial liabilities (7.8) (2.5) (3.3)
More than one year | Designated as continuing cash flow hedges      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial liabilities (7.8) (2.5) (3.3)
More than one year | Designated as continuing cash flow hedges      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial assets 92.4 15.4 3.3
Foreign currency risk | Cash Flow Hedges      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial assets 128.2 90.2 147.2
Derivative financial liabilities (79.6) (2.7) (3.3)
Net derivative financial assets (liabilities) 48.6 87.5 143.9
Foreign currency risk | Cash Flow Hedges | Property, plant and equipment - aircraft additions      
Disclosure of detailed information about hedging instruments [line items]      
Notional amount 3,243.1 373.8 518.1
Foreign currency risk | Cash Flow Hedges | Fuel and oil operating expenses      
Disclosure of detailed information about hedging instruments [line items]      
Notional amount 4,580.8 5,066.7 4,125.4
Foreign currency risk | Cash Flow Hedges | Less than one year      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial assets 35.8 84.4 144.0
Derivative financial liabilities (71.8) (0.2)  
Net derivative financial assets (liabilities) (36.0) 84.2 144.0
Foreign currency risk | Cash Flow Hedges | Less than one year | Property, plant and equipment - aircraft additions      
Disclosure of detailed information about hedging instruments [line items]      
Notional amount 553.8 373.8 494.0
Foreign currency risk | Cash Flow Hedges | Less than one year | Fuel and oil operating expenses      
Disclosure of detailed information about hedging instruments [line items]      
Notional amount 3,541.9 3,925.5 3,701.7
Foreign currency risk | Cash Flow Hedges | More than one year      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial assets 92.4 5.8 3.2
Derivative financial liabilities (7.8) (2.5) (3.3)
Net derivative financial assets (liabilities) 84.6 3.3 (0.1)
Foreign currency risk | Cash Flow Hedges | More than one year | Property, plant and equipment - aircraft additions      
Disclosure of detailed information about hedging instruments [line items]      
Notional amount 2,689.3   24.1
Foreign currency risk | Cash Flow Hedges | More than one year | Fuel and oil operating expenses      
Disclosure of detailed information about hedging instruments [line items]      
Notional amount 1,038.9 1,141.2 423.7
Commodity price risk | Cash Flow Hedges      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial assets 2,098.1 19.6 205.6
Derivative financial liabilities (70.5) (224.5) (178.8)
Net derivative financial assets (liabilities) 2,027.6 (204.9) 26.8
Commodity price risk | Cash Flow Hedges | Fuel and carbon operating expenses      
Disclosure of detailed information about hedging instruments [line items]      
Notional amount 3,381.8 3,900.9 3,716.0
Commodity price risk | Cash Flow Hedges | Less than one year      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial assets 2,098.1 10.0 205.5
Derivative financial liabilities (70.5) (224.5) (178.0)
Net derivative financial assets (liabilities) 2,027.6 (214.5) 27.5
Commodity price risk | Cash Flow Hedges | Less than one year | Fuel and carbon operating expenses      
Disclosure of detailed information about hedging instruments [line items]      
Notional amount € 3,381.8 3,424.5 3,713.8
Commodity price risk | Cash Flow Hedges | More than one year      
Disclosure of detailed information about hedging instruments [line items]      
Derivative financial assets   9.6 0.1
Derivative financial liabilities     (0.8)
Net derivative financial assets (liabilities)   9.6 (0.7)
Commodity price risk | Cash Flow Hedges | More than one year | Fuel and carbon operating expenses      
Disclosure of detailed information about hedging instruments [line items]      
Notional amount   € 476.4 € 2.2