v3.24.0.1
Employee benefit obligations - Present Value Defined Benefit Obligation (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)
Actuarial losses/(gains) from    
Employee benefit obligations at December 31 (2.2) (6.3)
Present value of defined benefit obligation    
Disclosure of defined benefit plans [line items]    
Employee benefit obligations at January 1 (23.7) (22.8)
Current service cost 3.8 3.4
Contributions by the employees 3.1 2.2
Interest expenses 0.5 0.1
Past service cost 0.0 (0.3)
Benefits paid 0.8 0.9
Actuarial losses/(gains) from    
changes in financial assumptions 3.6 (6.8)
changes in experience adjustments (0.2) 1.3
Employee benefit obligations at December 31 SFr (35.3) SFr (23.7)