v3.26.1
Intangible assets - Schedule of Intangible Assets (Details) - CHF (SFr)
SFr in Millions
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Intangible assets and goodwill at beginning of period SFr 54.2 SFr 58.3
Additions 5.3 2.2
Depreciation (4.7) (5.1)
Currency Translation 0.9  
Intangible assets and goodwill at end of the period 55.8 55.3
Cost    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Intangible assets and goodwill at beginning of period 111.3 105.7
Intangible assets and goodwill at end of the period 118.4 107.8
Accumulated depreciation    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Intangible assets and goodwill at beginning of period (57.1) (47.4)
Intangible assets and goodwill at end of the period (62.6) (52.5)
Patents, licenses and other rights    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Intangible assets and goodwill at beginning of period 45.1 47.5
Additions 1.8 1.0
Depreciation (2.7) (2.5)
Currency Translation 0.7  
Intangible assets and goodwill at end of the period 44.9 46.0
Patents, licenses and other rights | Cost    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Intangible assets and goodwill at beginning of period 74.5 71.8
Intangible assets and goodwill at end of the period 77.5 72.8
Patents, licenses and other rights | Accumulated depreciation    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Intangible assets and goodwill at beginning of period (29.4) (24.3)
Intangible assets and goodwill at end of the period (32.5) (26.8)
Software    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Intangible assets and goodwill at beginning of period 7.3 9.0
Additions 3.5 1.2
Depreciation (1.9) (2.6)
Currency Translation 0.1  
Intangible assets and goodwill at end of the period 9.0 7.5
Software | Cost    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Intangible assets and goodwill at beginning of period 35.0 32.1
Intangible assets and goodwill at end of the period 39.2 33.2
Software | Accumulated depreciation    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Intangible assets and goodwill at beginning of period (27.7) (23.1)
Intangible assets and goodwill at end of the period (30.1) (25.7)
Goodwill    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Intangible assets and goodwill at beginning of period 1.8 1.8
Additions 0.0 0.0
Depreciation 0.0 0.0
Currency Translation 0.0  
Intangible assets and goodwill at end of the period 1.8 1.8
Goodwill | Cost    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Intangible assets and goodwill at beginning of period 1.8 1.8
Intangible assets and goodwill at end of the period 1.8 1.8
Goodwill | Accumulated depreciation    
Reconciliation of changes in intangible assets other than goodwill [abstract]    
Intangible assets and goodwill at beginning of period 0.0 0.0
Intangible assets and goodwill at end of the period SFr 0.0 SFr 0.0