v3.24.2.u1
Intangible assets -Schedule of Intangible Assets (Details) - CHF (SFr)
SFr in Millions
 6 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Disclosure of detailed information about intangible assets [line items]    
Intangible assets and goodwill at beginning of period SFr 64.6 SFr 70.3
Additions 2.3 2.0
Depreciation (5.2) (4.9)
Intangible assets and goodwill at end of the period 61.7 67.4
Gross carrying amount    
Disclosure of detailed information about intangible assets [line items]    
Intangible assets and goodwill at beginning of period 101.2 96.9
Intangible assets and goodwill at end of the period 103.6 98.9
Accumulated depreciation    
Disclosure of detailed information about intangible assets [line items]    
Intangible assets and goodwill at beginning of period (36.6) (26.6)
Intangible assets and goodwill at end of the period (41.9) (31.5)
Patents, licenses and other rights    
Disclosure of detailed information about intangible assets [line items]    
Intangible assets and goodwill at beginning of period 50.9 54.2
Additions 0.5 0.1
Depreciation (2.3) (2.2)
Intangible assets and goodwill at end of the period 49.0 52.1
Patents, licenses and other rights | Gross carrying amount    
Disclosure of detailed information about intangible assets [line items]    
Intangible assets and goodwill at beginning of period 70.4 69.2
Intangible assets and goodwill at end of the period 70.9 69.3
Patents, licenses and other rights | Accumulated depreciation    
Disclosure of detailed information about intangible assets [line items]    
Intangible assets and goodwill at beginning of period (19.6) (15.0)
Intangible assets and goodwill at end of the period (21.9) (17.2)
Software    
Disclosure of detailed information about intangible assets [line items]    
Intangible assets and goodwill at beginning of period 11.9 14.4
Additions 1.8 1.9
Depreciation (2.9) (2.7)
Intangible assets and goodwill at end of the period 10.9 13.5
Software | Gross carrying amount    
Disclosure of detailed information about intangible assets [line items]    
Intangible assets and goodwill at beginning of period 29.0 25.9
Intangible assets and goodwill at end of the period 30.9 27.8
Software | Accumulated depreciation    
Disclosure of detailed information about intangible assets [line items]    
Intangible assets and goodwill at beginning of period (17.1) (11.6)
Intangible assets and goodwill at end of the period (20.0) (14.2)
Goodwill    
Disclosure of detailed information about intangible assets [line items]    
Intangible assets and goodwill at beginning of period 1.8 1.8
Additions 0.0 0.0
Depreciation 0.0 0.0
Intangible assets and goodwill at end of the period 1.8 1.8
Goodwill | Gross carrying amount    
Disclosure of detailed information about intangible assets [line items]    
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    
Disclosure of detailed information about intangible assets [line items]    
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