FI - Roll-forward of assets measured at fair value on recurring basis (Details 4) - CHF (SFr)
SFr in Millions
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Jan. 01, 2020
Assets measured at fair value on a recurring basis for level 3      
Retained Earnings (Accumulated Deficit) SFr 31,064 SFr 32,834  
Recurring basis | Securities received as collateral      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 101 1  
Transfers in, assets 0 0  
Transfers out, assets 0 0  
Purchases, assets 73 213  
Sales, assets (164) (106)  
Issuances, assets 0 0  
Settlements, assets 0 0  
Gain (loss) on transfers in/out included in trading revenues, assets 0 0  
Gain (loss) on all other activity included in trading revenues, assets 0 0  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 4 (7)  
Balance at end of period, assets 14 101  
Recurring basis | Securities received as collateral | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 0 0  
Recurring basis | Trading assets      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 7,535 7,885  
Transfers in, assets 1,345 3,255  
Transfers out, assets (3,413) (3,271)  
Purchases, assets 4,867 6,304  
Sales, assets (5,685) (6,740)  
Issuances, assets 874 2,064  
Settlements, assets (1,629) (2,968)  
Gain (loss) on transfers in/out included in trading revenues, assets (133) 290  
Gain (loss) on all other activity included in trading revenues, assets 509 1,598  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets (1) 5  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 234 (887)  
Balance at end of period, assets 4,503 7,535  
Recurring basis | Trading assets | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 52 1,377  
Recurring basis | Trading assets | Debt securities      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 2,253 1,923  
Transfers in, assets 878 2,078  
Transfers out, assets (1,701) (1,775)  
Purchases, assets 3,668 3,811  
Sales, assets (4,141) (3,493)  
Issuances, assets 0 0  
Settlements, assets 0 0  
Gain (loss) on transfers in/out included in trading revenues, assets (331) 1  
Gain (loss) on all other activity included in trading revenues, assets 509 14  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets (1) 5  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 91 (311)  
Balance at end of period, assets 1,225 2,253  
Recurring basis | Trading assets | Debt securities | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 103 166  
Recurring basis | Trading assets | Debt securities | Corporate debt securities      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,270 1,128  
Transfers in, assets 471 703  
Transfers out, assets (747) (809)  
Purchases, assets 2,753 2,685  
Sales, assets (3,483) (2,464)  
Issuances, assets 0 0  
Settlements, assets 0 0  
Gain (loss) on transfers in/out included in trading revenues, assets (321) 26  
Gain (loss) on all other activity included in trading revenues, assets 472 211  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 63 (210)  
Balance at end of period, assets 478 1,270  
Recurring basis | Trading assets | Debt securities | Corporate debt securities | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 154 196  
Recurring basis | Trading assets | Debt securities | RMBS      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 557    
Transfers in, assets 158    
Transfers out, assets (615)    
Purchases, assets 654    
Sales, assets (385)    
Issuances, assets 0    
Settlements, assets 0    
Gain (loss) on transfers in/out included in trading revenues, assets (25)    
Gain (loss) on all other activity included in trading revenues, assets 59    
Gain (loss) on transfers in/out included in other revenues, assets 0    
Gain (loss) on all other activity included in other revenues, assets 0    
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0    
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0    
Foreign currency translation impact, assets 21    
Balance at end of period, assets 424 557  
Recurring basis | Trading assets | Debt securities | RMBS | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (15)    
Recurring basis | Trading assets | Derivative instruments      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 3,911 3,534  
Transfers in, assets 314 995  
Transfers out, assets (1,551) (1,207)  
Purchases, assets 0 0  
Sales, assets 0 0  
Issuances, assets 874 2,064  
Settlements, assets (1,514) (2,891)  
Gain (loss) on transfers in/out included in trading revenues, assets 79 213  
Gain (loss) on all other activity included in trading revenues, assets (16) 1,607  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 1  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 90 (405)  
Balance at end of period, assets 2,187 3,911  
Recurring basis | Trading assets | Derivative instruments | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 116 1,323  
Recurring basis | Trading assets | Derivative instruments | Interest rate derivatives      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 733    
Transfers in, assets 58    
Transfers out, assets (222)    
Purchases, assets 0    
Sales, assets 0    
Issuances, assets 175    
Settlements, assets (79)    
Gain (loss) on transfers in/out included in trading revenues, assets (8)    
Gain (loss) on all other activity included in trading revenues, assets (14)    
Gain (loss) on transfers in/out included in other revenues, assets 0    
Gain (loss) on all other activity included in other revenues, assets 0    
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0    
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0    
Foreign currency translation impact, assets (19)    
Balance at end of period, assets 624 733  
Recurring basis | Trading assets | Derivative instruments | Interest rate derivatives | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 141    
Recurring basis | Trading assets | Derivative instruments | Equity/Index-related products      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,186 1,040  
Transfers in, assets   255  
Transfers out, assets   (519)  
Purchases, assets   0  
Sales, assets   0  
Issuances, assets   507  
Settlements, assets   (743)  
Gain (loss) on transfers in/out included in trading revenues, assets   107  
Gain (loss) on all other activity included in trading revenues, assets   725  
Gain (loss) on transfers in/out included in other revenues, assets   0  
Gain (loss) on all other activity included in other revenues, assets   0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets   0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets   0  
Foreign currency translation impact, assets   (186)  
Balance at end of period, assets   1,186  
Recurring basis | Trading assets | Derivative instruments | Equity/Index-related products | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses   752  
Recurring basis | Trading assets | Derivative instruments | Other derivatives      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,079 909  
Transfers in, assets 1 0  
Transfers out, assets 0 0  
Purchases, assets 0 0  
Sales, assets 0 0  
Issuances, assets 311 303  
Settlements, assets (325) (326)  
Gain (loss) on transfers in/out included in trading revenues, assets 0 (1)  
Gain (loss) on all other activity included in trading revenues, assets (73) 291  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 41 (97)  
Balance at end of period, assets 1,034 1,079  
Recurring basis | Trading assets | Derivative instruments | Other derivatives | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (81) 310  
Recurring basis | Trading assets | Other      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,247 2,231  
Transfers in, assets 31 119  
Transfers out, assets (90) (246)  
Purchases, assets 1,035 2,420  
Sales, assets (1,371) (3,189)  
Issuances, assets 0 0  
Settlements, assets (115) (77)  
Gain (loss) on transfers in/out included in trading revenues, assets 62 72  
Gain (loss) on all other activity included in trading revenues, assets 49 76  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 (1)  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 48 (158)  
Balance at end of period, assets 896 1,247  
Recurring basis | Trading assets | Other | Other derivatives | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (96) (87)  
Recurring basis | Other investments      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 3,054 2,523  
Transfers in, assets 99 8  
Transfers out, assets (758) 0  
Purchases, assets 1,517 442  
Sales, assets (663) (194)  
Issuances, assets 0 0  
Settlements, assets 0 0  
Gain (loss) on transfers in/out included in trading revenues, assets 0 0  
Gain (loss) on all other activity included in trading revenues, assets 86 112  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 267 286  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 64 (123)  
Balance at end of period, assets 3,666 3,054  
Recurring basis | Other investments | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 120 409  
Recurring basis | Other investments | Other equity investments      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 2,132 1,463  
Transfers in, assets 65 7  
Transfers out, assets (757) 0  
Purchases, assets 1,482 408  
Sales, assets (448) (22)  
Issuances, assets 0 0  
Settlements, assets 0 0  
Gain (loss) on transfers in/out included in trading revenues, assets 0 0  
Gain (loss) on all other activity included in trading revenues, assets 96 13  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 263 293  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 30 (30)  
Balance at end of period, assets 2,863 2,132  
Recurring basis | Other investments | Other equity investments | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 80 298  
Recurring basis | Other investments | Life finance instruments      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 920 1,052  
Transfers in, assets 0 0  
Transfers out, assets 0 0  
Purchases, assets 33 34  
Sales, assets (188) (172)  
Issuances, assets 0 0  
Settlements, assets 0 0  
Gain (loss) on transfers in/out included in trading revenues, assets 0 0  
Gain (loss) on all other activity included in trading revenues, assets (10) 99  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 34 (93)  
Balance at end of period, assets 789 920  
Recurring basis | Other investments | Life finance instruments | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 39 112  
Recurring basis | Loans      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 3,669 3,835  
Transfers in, assets 257 1,268  
Transfers out, assets (1,315) (549)  
Purchases, assets 362 437  
Sales, assets (194) (640)  
Issuances, assets 207 1,170  
Settlements, assets (1,620) (1,435)  
Gain (loss) on transfers in/out included in trading revenues, assets 7 52  
Gain (loss) on all other activity included in trading revenues, assets 55 (164)  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets (3) 1  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 109 (306)  
Balance at end of period, assets 1,534 3,669  
Recurring basis | Loans | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (59) (97)  
Recurring basis | Commercial and industrial loans      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,347 1,401  
Transfers in, assets 213 446  
Transfers out, assets (364) (170)  
Purchases, assets 10 184  
Sales, assets (133) (442)  
Issuances, assets 162 610  
Settlements, assets (643) (435)  
Gain (loss) on transfers in/out included in trading revenues, assets 19 6  
Gain (loss) on all other activity included in trading revenues, assets 74 (150)  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets (3) 1  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 35 (104)  
Balance at end of period, assets 717 1,347  
Recurring basis | Commercial and industrial loans | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 6 (183)  
Recurring basis | Financial institutions loans      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,082 1,201  
Transfers in, assets 43 238  
Transfers out, assets (340) (245)  
Purchases, assets 0 0  
Sales, assets (42) (31)  
Issuances, assets 34 499  
Settlements, assets (409) (531)  
Gain (loss) on transfers in/out included in trading revenues, assets 1 20  
Gain (loss) on all other activity included in trading revenues, assets 70 43  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 26 (112)  
Balance at end of period, assets 465 1,082  
Recurring basis | Financial institutions loans | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 27 47  
Recurring basis | Other intangible assets      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 180 244  
Transfers in, assets 0 0  
Transfers out, assets 0 0  
Purchases, assets 22 0  
Sales, assets 0 0  
Issuances, assets 0 0  
Settlements, assets 0 0  
Gain (loss) on transfers in/out included in trading revenues, assets 0 0  
Gain (loss) on all other activity included in trading revenues, assets 0 0  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets (42) (44)  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 7 (20)  
Balance at end of period, assets 167 180  
Recurring basis | Other intangible assets | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (42) (44)  
Recurring basis | Other assets      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,825 1,846  
Transfers in, assets 370 1,440  
Transfers out, assets (902) (709)  
Purchases, assets 3,447 4,553  
Sales, assets (3,269) (4,595)  
Issuances, assets 120 547  
Settlements, assets (924) (995)  
Gain (loss) on transfers in/out included in trading revenues, assets 14 (17)  
Gain (loss) on all other activity included in trading revenues, assets (41) (14)  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 54 (231)  
Balance at end of period, assets 694 1,825  
Recurring basis | Other assets | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (137) (48)  
Recurring basis | Other assets - of which loans held-for-sale      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,576 1,619  
Transfers in, assets 360 1,380  
Transfers out, assets (855) (665)  
Purchases, assets 3,394 4,504  
Sales, assets (3,222) (4,567)  
Issuances, assets 120 547  
Settlements, assets (921) (994)  
Gain (loss) on transfers in/out included in trading revenues, assets 25 (41)  
Gain (loss) on all other activity included in trading revenues, assets 41 4  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 44 (211)  
Balance at end of period, assets 562 1,576  
Recurring basis | Other assets - of which loans held-for-sale | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (104) (73)  
Recurring basis | Assets      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 16,364 16,334  
Transfers in, assets 2,071 5,971  
Transfers out, assets (6,388) (4,529)  
Purchases, assets 10,288 11,949  
Sales, assets (9,975) (12,275)  
Issuances, assets 1,201 3,781  
Settlements, assets (4,173) (5,398)  
Gain (loss) on transfers in/out included in trading revenues, assets (112) 325  
Gain (loss) on all other activity included in trading revenues, assets 609 1,532  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 221 248  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 472 (1,574)  
Balance at end of period, assets 10,578 16,364  
Recurring basis | Assets | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (66) 1,597  
Nonrecurring basis | Accounting Standards Update 2019-05 [Member] | Revision of Prior Period, Accounting Standards Update, Adjustment [Member]      
Assets measured at fair value on a recurring basis for level 3      
Retained Earnings (Accumulated Deficit)     SFr 118
Bank      
Assets measured at fair value on a recurring basis for level 3      
Retained Earnings (Accumulated Deficit) 14,932 15,871  
Bank | Recurring basis | Securities received as collateral      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 101 1  
Transfers in, assets 0 0  
Transfers out, assets 0 0  
Purchases, assets 73 213  
Sales, assets (164) (106)  
Issuances, assets 0 0  
Settlements, assets 0 0  
Gain (loss) on transfers in/out included in trading revenues, assets 0 0  
Gain (loss) on all other activity included in trading revenues, assets 0 0  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 4 (7)  
Balance at end of period, assets 14 101  
Bank | Recurring basis | Securities received as collateral | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 0 0  
Bank | Recurring basis | Trading assets      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 7,535 7,885  
Transfers in, assets 1,345 3,255  
Transfers out, assets (3,413) (3,271)  
Purchases, assets 4,867 6,304  
Sales, assets (5,685) (6,740)  
Issuances, assets 874 2,064  
Settlements, assets (1,629) (2,968)  
Gain (loss) on transfers in/out included in trading revenues, assets (133) 290  
Gain (loss) on all other activity included in trading revenues, assets 509 1,598  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets (1) 5  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 234 (887)  
Balance at end of period, assets 4,503 7,535  
Bank | Recurring basis | Trading assets | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 52 1,377  
Bank | Recurring basis | Trading assets | Debt securities      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 2,253 1,923  
Transfers in, assets 878 2,078  
Transfers out, assets (1,701) (1,775)  
Purchases, assets 3,668 3,811  
Sales, assets (4,141) (3,493)  
Issuances, assets 0 0  
Settlements, assets 0 0  
Gain (loss) on transfers in/out included in trading revenues, assets (331) 1  
Gain (loss) on all other activity included in trading revenues, assets 509 14  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets (1) 5  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 91 (311)  
Balance at end of period, assets 1,225 2,253  
Bank | Recurring basis | Trading assets | Debt securities | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 103 166  
Bank | Recurring basis | Trading assets | Debt securities | Corporate debt securities      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,270 1,128  
Transfers in, assets 471 703  
Transfers out, assets (747) (809)  
Purchases, assets 2,753 2,685  
Sales, assets (3,483) (2,464)  
Issuances, assets 0 0  
Settlements, assets 0 0  
Gain (loss) on transfers in/out included in trading revenues, assets (321) 26  
Gain (loss) on all other activity included in trading revenues, assets 472 211  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 63 (210)  
Balance at end of period, assets 478 1,270  
Bank | Recurring basis | Trading assets | Debt securities | Corporate debt securities | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 154 196  
Bank | Recurring basis | Trading assets | Debt securities | RMBS      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 557    
Transfers in, assets 158    
Transfers out, assets (615)    
Purchases, assets 654    
Sales, assets (385)    
Issuances, assets 0    
Settlements, assets 0    
Gain (loss) on transfers in/out included in trading revenues, assets (25)    
Gain (loss) on all other activity included in trading revenues, assets 59    
Gain (loss) on transfers in/out included in other revenues, assets 0    
Gain (loss) on all other activity included in other revenues, assets 0    
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0    
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0    
Foreign currency translation impact, assets 21    
Balance at end of period, assets 424 557  
Bank | Recurring basis | Trading assets | Debt securities | RMBS | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (15)    
Bank | Recurring basis | Trading assets | Derivative instruments      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 3,911 3,534  
Transfers in, assets 314 995  
Transfers out, assets (1,551) (1,207)  
Purchases, assets 0 0  
Sales, assets 0 0  
Issuances, assets 874 2,064  
Settlements, assets (1,514) (2,891)  
Gain (loss) on transfers in/out included in trading revenues, assets 79 213  
Gain (loss) on all other activity included in trading revenues, assets (16) 1,607  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 1  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 90 (405)  
Balance at end of period, assets 2,187 3,911  
Bank | Recurring basis | Trading assets | Derivative instruments | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 116 1,323  
Bank | Recurring basis | Trading assets | Derivative instruments | Interest rate derivatives      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 733    
Transfers in, assets 58    
Transfers out, assets (222)    
Purchases, assets 0    
Sales, assets 0    
Issuances, assets 175    
Settlements, assets (79)    
Gain (loss) on transfers in/out included in trading revenues, assets (8)    
Gain (loss) on all other activity included in trading revenues, assets (14)    
Gain (loss) on transfers in/out included in other revenues, assets 0    
Gain (loss) on all other activity included in other revenues, assets 0    
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0    
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0    
Foreign currency translation impact, assets (19)    
Balance at end of period, assets 624 733  
Bank | Recurring basis | Trading assets | Derivative instruments | Interest rate derivatives | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 141    
Bank | Recurring basis | Trading assets | Derivative instruments | Equity/Index-related products      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,186 1,040  
Transfers in, assets   255  
Transfers out, assets   (519)  
Purchases, assets   0  
Sales, assets   0  
Issuances, assets   507  
Settlements, assets   (743)  
Gain (loss) on transfers in/out included in trading revenues, assets   107  
Gain (loss) on all other activity included in trading revenues, assets   725  
Gain (loss) on transfers in/out included in other revenues, assets   0  
Gain (loss) on all other activity included in other revenues, assets   0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets   0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets   0  
Foreign currency translation impact, assets   (186)  
Balance at end of period, assets   1,186  
Bank | Recurring basis | Trading assets | Derivative instruments | Equity/Index-related products | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses   752  
Bank | Recurring basis | Trading assets | Derivative instruments | Other derivatives      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,079 909  
Transfers in, assets 1 0  
Transfers out, assets 0 0  
Purchases, assets 0 0  
Sales, assets 0 0  
Issuances, assets 311 303  
Settlements, assets (325) (326)  
Gain (loss) on transfers in/out included in trading revenues, assets 0 (1)  
Gain (loss) on all other activity included in trading revenues, assets (73) 291  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 41 (97)  
Balance at end of period, assets 1,034 1,079  
Bank | Recurring basis | Trading assets | Derivative instruments | Other derivatives | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (81) 310  
Bank | Recurring basis | Trading assets | Other      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,247 2,231  
Transfers in, assets 31 119  
Transfers out, assets (90) (246)  
Purchases, assets 1,035 2,420  
Sales, assets (1,371) (3,189)  
Issuances, assets 0 0  
Settlements, assets (115) (77)  
Gain (loss) on transfers in/out included in trading revenues, assets 62 72  
Gain (loss) on all other activity included in trading revenues, assets 49 76  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 (1)  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 48 (158)  
Balance at end of period, assets 896 1,247  
Bank | Recurring basis | Trading assets | Other | Other derivatives | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (96) (87)  
Bank | Recurring basis | Other investments      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 3,054 2,523  
Transfers in, assets 99 8  
Transfers out, assets (758) 0  
Purchases, assets 1,513 442  
Sales, assets (658) (194)  
Issuances, assets 0 0  
Settlements, assets 0 0  
Gain (loss) on transfers in/out included in trading revenues, assets 0 0  
Gain (loss) on all other activity included in trading revenues, assets 86 112  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 267 286  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 63 (123)  
Balance at end of period, assets 3,666 3,054  
Bank | Recurring basis | Other investments | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 120 409  
Bank | Recurring basis | Other investments | Other equity investments      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 2,132 1,463  
Transfers in, assets 65 7  
Transfers out, assets (757) 0  
Purchases, assets 1,478 408  
Sales, assets (443) (22)  
Issuances, assets 0 0  
Settlements, assets 0 0  
Gain (loss) on transfers in/out included in trading revenues, assets 0 0  
Gain (loss) on all other activity included in trading revenues, assets 96 13  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 262 293  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 30 (30)  
Balance at end of period, assets 2,863 2,132  
Bank | Recurring basis | Other investments | Other equity investments | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 80 298  
Bank | Recurring basis | Other investments | Life finance instruments      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 920 1,052  
Transfers in, assets 0 0  
Transfers out, assets 0 0  
Purchases, assets 33 34  
Sales, assets (188) (172)  
Issuances, assets 0 0  
Settlements, assets 0 0  
Gain (loss) on transfers in/out included in trading revenues, assets 0 0  
Gain (loss) on all other activity included in trading revenues, assets (10) 99  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 34 (93)  
Balance at end of period, assets 789 920  
Bank | Recurring basis | Other investments | Life finance instruments | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 39 112  
Bank | Recurring basis | Loans      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 3,669 3,835  
Transfers in, assets 257 1,268  
Transfers out, assets (1,315) (549)  
Purchases, assets 362 437  
Sales, assets (194) (640)  
Issuances, assets 207 1,170  
Settlements, assets (1,620) (1,435)  
Gain (loss) on transfers in/out included in trading revenues, assets 7 52  
Gain (loss) on all other activity included in trading revenues, assets 55 (164)  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets (3) 1  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 109 (306)  
Balance at end of period, assets 1,534 3,669  
Bank | Recurring basis | Loans | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (59) (97)  
Bank | Recurring basis | Commercial and industrial loans      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,347 1,402  
Transfers in, assets 213 446  
Transfers out, assets (364) (170)  
Purchases, assets 10 184  
Sales, assets (133) (442)  
Issuances, assets 162 610  
Settlements, assets (643) (435)  
Gain (loss) on transfers in/out included in trading revenues, assets 19 6  
Gain (loss) on all other activity included in trading revenues, assets 74 (150)  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets (3) 1  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 35 (105)  
Balance at end of period, assets 717 1,347  
Bank | Recurring basis | Commercial and industrial loans | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 6 (183)  
Bank | Recurring basis | Financial institutions loans      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,082 1,201  
Transfers in, assets 43 238  
Transfers out, assets (340) (245)  
Purchases, assets 0 0  
Sales, assets (42) (31)  
Issuances, assets 34 499  
Settlements, assets (409) (531)  
Gain (loss) on transfers in/out included in trading revenues, assets 1 20  
Gain (loss) on all other activity included in trading revenues, assets 70 43  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 26 (112)  
Balance at end of period, assets 465 1,082  
Bank | Recurring basis | Financial institutions loans | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses 27 47  
Bank | Recurring basis | Other intangible assets      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 180 244  
Transfers in, assets 0 0  
Transfers out, assets 0 0  
Purchases, assets 22 0  
Sales, assets 0 0  
Issuances, assets 0 0  
Settlements, assets 0 0  
Gain (loss) on transfers in/out included in trading revenues, assets 0 0  
Gain (loss) on all other activity included in trading revenues, assets 0 0  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets (42) (44)  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 7 (20)  
Balance at end of period, assets 167 180  
Bank | Recurring basis | Other intangible assets | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (42) (44)  
Bank | Recurring basis | Other assets      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,825 1,846  
Transfers in, assets 370 1,440  
Transfers out, assets (902) (709)  
Purchases, assets 3,447 4,553  
Sales, assets (3,269) (4,595)  
Issuances, assets 120 547  
Settlements, assets (924) (995)  
Gain (loss) on transfers in/out included in trading revenues, assets 14 (17)  
Gain (loss) on all other activity included in trading revenues, assets (41) (14)  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 54 (231)  
Balance at end of period, assets 694 1,825  
Bank | Recurring basis | Other assets | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (137) (48)  
Bank | Recurring basis | Other assets - of which loans held-for-sale      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 1,576 1,619  
Transfers in, assets 360 1,380  
Transfers out, assets (855) (665)  
Purchases, assets 3,394 4,504  
Sales, assets (3,222) (4,567)  
Issuances, assets 120 547  
Settlements, assets (921) (994)  
Gain (loss) on transfers in/out included in trading revenues, assets 25 (41)  
Gain (loss) on all other activity included in trading revenues, assets 41 4  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 0 0  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 44 (211)  
Balance at end of period, assets 562 1,576  
Bank | Recurring basis | Other assets - of which loans held-for-sale | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses (104) (73)  
Bank | Recurring basis | Assets      
Assets measured at fair value on a recurring basis for level 3      
Balance at beginning of period, assets 16,364 16,334  
Transfers in, assets 2,071 5,971  
Transfers out, assets (6,388) (4,529)  
Purchases, assets 10,284 11,949  
Sales, assets (9,970) (12,275)  
Issuances, assets 1,201 3,781  
Settlements, assets (4,173) (5,398)  
Gain (loss) on transfers in/out included in trading revenues, assets (112) 325  
Gain (loss) on all other activity included in trading revenues, assets 609 1,532  
Gain (loss) on transfers in/out included in other revenues, assets 0 0  
Gain (loss) on all other activity included in other revenues, assets 221 248  
Gain (loss) on transfers in/out included in accumulated other comprehensive income, assets 0 0  
Gain (loss) on all other activity included in accumulated other comprehensive income, assets 0 0  
Foreign currency translation impact, assets 471 (1,574)  
Balance at end of period, assets 10,578 16,364  
Bank | Recurring basis | Assets | Net Revenue [Member]      
Assets measured at fair value on a recurring basis for level 3      
Changes in unrealized gains/losses SFr (66) SFr 1,597  
Bank | Nonrecurring basis | Accounting Standards Update 2019-05 [Member] | Revision of Prior Period, Accounting Standards Update, Adjustment [Member]      
Assets measured at fair value on a recurring basis for level 3      
Retained Earnings (Accumulated Deficit)     SFr 119