v3.25.3
Leases - Summary of Right-of-use assets and Lease Liabilities (Details) - EUR (€)
€ in Thousands
 12 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2023
Disclosure of quantitative information about right-of-use assets [line items]      
Right-of-use assets, beginning balance € 171,334    
Right-of-use assets, ending balance 179,762 € 171,334  
Lease liabilities      
Lease liabilities, beginning balance 184,073 130,059  
Additions, net 57,910 95,711  
Lease payments (51,714) (47,196)  
Interest 8,996 9,402 € 5,721
Impact of foreign currency translation (6,346) (3,903)  
Lease liabilities, ending balance 192,919 184,073 130,059
Accumulated Depreciation      
Disclosure of quantitative information about right-of-use assets [line items]      
Right of use assets accumulated depreciation, beginning balance (93,529) (59,587)  
Depreciation (45,788) (42,279)  
Derecognition on termination 14,689 6,153  
Impact of foreign currency translation 3,468 2,184  
Right of use assets accumulated depreciation, ending balance (121,160) (93,529) (59,587)
Cost      
Disclosure of quantitative information about right-of-use assets [line items]      
Right-of-use assets, beginning balance 264,863 182,571  
Additions 69,498 96,544  
Derecognition on termination (24,274) (7,512)  
Impact of foreign currency translation (9,165) (6,740)  
Right-of-use assets, ending balance 300,922 264,863 182,571
Buildings      
Disclosure of quantitative information about right-of-use assets [line items]      
Right-of-use assets, beginning balance 157,964    
Right-of-use assets, ending balance 166,879 157,964  
Lease liabilities      
Lease liabilities, beginning balance 168,985 126,446  
Additions, net 52,755 79,705  
Lease payments (45,148) (41,323)  
Interest 8,163 8,066  
Impact of foreign currency translation (6,020) (3,909)  
Lease liabilities, ending balance 178,735 168,985 126,446
Buildings | Accumulated Depreciation      
Disclosure of quantitative information about right-of-use assets [line items]      
Right of use assets accumulated depreciation, beginning balance (88,080) (57,736)  
Depreciation (40,433) (37,926)  
Derecognition on termination 13,671 5,551  
Impact of foreign currency translation 3,178 2,031  
Right of use assets accumulated depreciation, ending balance (111,664) (88,080) (57,736)
Buildings | Cost      
Disclosure of quantitative information about right-of-use assets [line items]      
Right-of-use assets, beginning balance 246,044 177,139  
Additions 64,289 81,869  
Derecognition on termination (23,199) (6,721)  
Impact of foreign currency translation (8,591) (6,243)  
Right-of-use assets, ending balance 278,543 246,044 177,139
Vehicles      
Disclosure of quantitative information about right-of-use assets [line items]      
Right-of-use assets, beginning balance 5,088    
Right-of-use assets, ending balance 5,569 5,088  
Lease liabilities      
Lease liabilities, beginning balance 5,183 3,613  
Additions, net 2,583 3,166  
Lease payments (2,275) (1,783)  
Interest 218 181  
Impact of foreign currency translation 2 6  
Lease liabilities, ending balance 5,711 5,183 3,613
Vehicles | Accumulated Depreciation      
Disclosure of quantitative information about right-of-use assets [line items]      
Right of use assets accumulated depreciation, beginning balance (2,921) (1,851)  
Depreciation (2,114) (1,668)  
Derecognition on termination 1,018 602  
Impact of foreign currency translation   (4)  
Right of use assets accumulated depreciation, ending balance (4,017) (2,921) (1,851)
Vehicles | Cost      
Disclosure of quantitative information about right-of-use assets [line items]      
Right-of-use assets, beginning balance 8,009 5,432  
Additions 2,650 3,363  
Derecognition on termination (1,075) (791)  
Impact of foreign currency translation 2 5  
Right-of-use assets, ending balance 9,586 8,009 € 5,432
Other      
Disclosure of quantitative information about right-of-use assets [line items]      
Right-of-use assets, beginning balance 8,282    
Right-of-use assets, ending balance 7,314 8,282  
Lease liabilities      
Lease liabilities, beginning balance 9,905    
Additions, net 2,572 12,840  
Lease payments (4,291) (4,090)  
Interest 615 1,155  
Impact of foreign currency translation (328)    
Lease liabilities, ending balance 8,473 9,905  
Other | Accumulated Depreciation      
Disclosure of quantitative information about right-of-use assets [line items]      
Right of use assets accumulated depreciation, beginning balance 2,528    
Depreciation (3,241) (2,685)  
Impact of foreign currency translation 290 157  
Right of use assets accumulated depreciation, ending balance (5,479) 2,528  
Other | Cost      
Disclosure of quantitative information about right-of-use assets [line items]      
Right-of-use assets, beginning balance 10,810    
Additions 2,559 11,312  
Impact of foreign currency translation (576) (502)  
Right-of-use assets, ending balance € 12,793 € 10,810