v3.25.4
EMPLOYEE BENEFIT OBLIGAITONS - Movement in Fair Value of Plan Assets (Details) - Fair value of plan assets - CHF (SFr)
SFr in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of net defined benefit liability (asset) [line items]    
Balance as of January 1 SFr 851.4 SFr 793.7
Included in the consolidated statements of income or loss    
Interest income 7.8 10.1
Settlements 0.0 0.0
Included in consolidated statements of other comprehensive income    
Return on plan assets excluding interest income 36.5 48.4
Other    
Employer contributions 26.9 26.6
Employee contributions 19.8 20.1
Benefits paid (66.3) (47.5)
Total fair value of plan assets as of December 31 SFr 876.0 SFr 851.4