v3.25.4
Retirement benefit plan - Changes in Defined Benefit Obligation (Details) - CHF (SFr)
SFr in Thousands
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Changes in defined benefit obligation [Abstract]      
At beginning of period SFr (8,844) SFr (5,770) SFr (3,213)
At end of period (8,645) (8,844) (5,770)
Defined Benefit Obligation      
Changes in defined benefit obligation [Abstract]      
At beginning of period (52,455) (41,060) (32,410)
Current service cost (1,952) (1,688) (1,453)
Past service cost     (903)
Interest cost (544) (680) (804)
Change in demographic assumptions 0 (16) 136
Change in financial assumptions (2,652) (3,846) (2,908)
Change in experience assumptions 831 (1,078) (57)
Benefits (deposited)/paid 4,119 (2,504) (1,265)
Gains and (losses) on settlement / curtailment 6,057    
Employees' contributions (1,665) (1,583) (1,396)
At end of period SFr (48,261) SFr (52,455) SFr (41,060)