v3.25.4
FINANCIAL INSTRUMENTS & RISK - Allowance for Expected Credit Losses (Details) - CHF (SFr)
SFr in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Increase (decrease) in financial assets [abstract]    
Allowance at January 1 SFr 167.6  
Allowance at December 31 150.5 SFr 167.6
Accumulated impairment | Trade receivables    
Increase (decrease) in financial assets [abstract]    
Allowance at January 1 (31.9) (30.6)
Provisions for impairment of trade receivables (19.9) (30.8)
Write-off of receivables 12.5 29.5
Impact from change in estimate (ECL) (57.8) 0.0
Allowance at December 31 SFr (97.1) SFr (31.9)