Other investments (Details) - CHF (SFr)
SFr in Millions
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Other investments      
Other investments SFr 5,826 SFr 5,412  
Accumulated depreciation, real estate held for investment 32 35 SFr 34
Impairment charges 0 1 0
Foreclosed or Repossessed, Real Estate [Member]      
Other investments      
Other investments 9 16  
Equity method investments      
Other investments      
Other investments 1,644 2,631  
Equity securities (without a readily determinable fair value)      
Other investments      
Other investments 3,317 1,779  
of which at net asset value      
Other investments      
Other investments 54 113  
of which at measurement alternative      
Other investments      
Other investments 347 359  
of which at fair value      
Other investments      
Other investments 2,869 1,278  
of which at cost less impairment      
Other investments      
Other investments 47 29  
Real estate held for investment      
Other investments      
Other investments 76 82  
Real estate held for investment | Foreclosed or Repossessed, Real Estate [Member]      
Other investments      
Other investments 6 13  
Life finance instruments      
Other investments      
Other investments 789 920  
Bank      
Other investments      
Other investments 5,788 5,379  
Accumulated depreciation, real estate held for investment 28 31 29
Impairment charges 0 1 SFr 0
Bank | Foreclosed or Repossessed, Real Estate [Member]      
Other investments      
Other investments 9 16  
Bank | Equity method investments      
Other investments      
Other investments 1,636 2,624  
Bank | Equity securities (without a readily determinable fair value)      
Other investments      
Other investments 3,315 1,776  
Bank | of which at net asset value      
Other investments      
Other investments 53 111  
Bank | of which at measurement alternative      
Other investments      
Other investments 345 357  
Bank | of which at fair value      
Other investments      
Other investments 2,869 1,278  
Bank | of which at cost less impairment      
Other investments      
Other investments 48 30  
Bank | Real estate held for investment      
Other investments      
Other investments 48 59  
Bank | Real estate held for investment | Foreclosed or Repossessed, Real Estate [Member]      
Other investments      
Other investments 6 13  
Bank | Life finance instruments      
Other investments      
Other investments SFr 789 SFr 920