v3.25.4
Employee benefit obligations - Narrative (Details) - CHF (SFr)
SFr in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of defined benefit plans [abstract]    
Estimate of contributions expected to be paid to plan for next annual reporting period SFr 9.4  
Employee benefit expenses SFr 5.8 SFr 4.5
Weighted average duration of defined benefit obligation 14 years 15 years 8 months 12 days