v3.24.0.1
Employee benefit obligations - Plan Assets (Details) - CHF (SFr)
SFr in Millions
12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Disclosure of defined benefit plans [line items]    
Employee benefit obligations at January 1 SFr (6.3) SFr (5.9)
Employee benefit obligations at December 31 (2.2) (6.3)
Plan assets    
Disclosure of defined benefit plans [line items]    
Employee benefit obligations at January 1 17.4 17.0
Contributions by the employer 11.3 (1.8)
Contributions by the employees 3.1 2.2
Interest income 0.5 0.1
Benefits paid 0.8 0.9
Return on plan assets excl. interest income 0.0 (1.1)
Employee benefit obligations at December 31 SFr 33.1 SFr 17.4