Revenue from contracts with customers (Details 2) - CHF (SFr)
SFr in Millions
3 Months Ended
Dec. 31, 2021
Sep. 30, 2021
Jun. 30, 2021
Mar. 31, 2021
Dec. 31, 2020
Contract balances [Line Items]          
Accounts Receivable, Net SFr 865       SFr 1,001
Contract with Customer, Liability 55       48
Contract with Customer, Liability, Revenue Recognized 9 SFr 10 SFr 18 SFr 8  
Bank          
Contract balances [Line Items]          
Accounts Receivable, Net 865       993
Contract with Customer, Liability 55       SFr 48
Contract with Customer, Liability, Revenue Recognized SFr 9 SFr 10 SFr 18 SFr 8