v3.25.3
Goodwill - Summary of Goodwill Balance Allocation into Current and Previous Groups of CGUs (Details) - EUR (€)
€ in Thousands
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Disclosure of reconciliation of changes in goodwill [line items]      
Goodwill € 1,512,270 € 1,554,621 € 1,593,917
CGUs      
Disclosure of reconciliation of changes in goodwill [line items]      
Goodwill 1,512,270 1,554,621  
CGUs | Americas      
Disclosure of reconciliation of changes in goodwill [line items]      
Goodwill 552,947 579,864  
CGUs | Europe      
Disclosure of reconciliation of changes in goodwill [line items]      
Goodwill   743,157  
CGUs | EMEA      
Disclosure of reconciliation of changes in goodwill [line items]      
Goodwill 792,723    
CGUs | ASPA      
Disclosure of reconciliation of changes in goodwill [line items]      
Goodwill   165,235  
CGUs | APAC      
Disclosure of reconciliation of changes in goodwill [line items]      
Goodwill € 166,600    
CGUs | MEAI      
Disclosure of reconciliation of changes in goodwill [line items]      
Goodwill   € 66,365