v3.25.0.1
Goodwill and intangible assets - Summary of Goodwill and Intangible Assets (Details) - EUR (€)
€ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance, intangible assets € 84  
Ending balance, intangible assets 48 € 84
Beginning balance 1,221  
Ending balance 1,249 1,221
Internal development costs and patents    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance, intangible assets 13  
Ending balance, intangible assets 8 13
Acquired intangible assets    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance, intangible assets 71  
Ending balance, intangible assets 40 71
Goodwill    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 1,137  
Ending balance 1,201 1,137
Cost    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance, intangible assets 236 262
Additions 3 8
Write-off of fully amortized intangible assets (30) (29)
Reclassifications (10)  
Exchange differences 6 (5)
Ending balance, intangible assets 205 236
Beginning balance 1,373 1,430
Additions 3 8
Write-off of fully amortized intangible assets (30) (29)
Reclassifications (10)  
Exchange differences 70 (36)
Ending balance 1,406 1,373
Cost | Internal development costs and patents    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance, intangible assets 68 69
Additions 3 8
Write-off of fully amortized intangible assets (7) (8)
Reclassifications 0  
Exchange differences 0 (1)
Ending balance, intangible assets 64 68
Cost | Acquired intangible assets    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance, intangible assets 168 193
Additions 0 0
Write-off of fully amortized intangible assets (23) (21)
Reclassifications (10)  
Exchange differences 6 (4)
Ending balance, intangible assets 141 168
Cost | Goodwill    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance 1,137 1,168
Additions 0 0
Write-off of fully amortized intangible assets 0 0
Reclassifications 0  
Exchange differences 64 (31)
Ending balance 1,201 1,137
Accumulated amortization    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance, intangible assets (152) (135)
Amortization charge (36) (48)
Write-off of fully amortized intangible assets 30 29
Reclassifications 6  
Exchange differences (5) 2
Ending balance, intangible assets (157) (152)
Accumulated amortization | Internal development costs and patents    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance, intangible assets (55) (50)
Amortization charge (8) (12)
Write-off of fully amortized intangible assets 7 8
Reclassifications 0  
Exchange differences 0 (1)
Ending balance, intangible assets (56) (55)
Accumulated amortization | Acquired intangible assets    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Beginning balance, intangible assets (97) (85)
Amortization charge (28) (36)
Write-off of fully amortized intangible assets 23 21
Reclassifications 6  
Exchange differences (5) 3
Ending balance, intangible assets € (101) € (97)