v3.21.2
Loans - Summary of Loans (Detail) - USD ($)
$ in Millions
Sep. 30, 2021
Jun. 30, 2021
Dec. 31, 2020
Sep. 30, 2020
Jun. 30, 2020
Dec. 31, 2019
Loans Receivable [Line Items]            
Gross loans receivable $ 146,956   $ 119,989      
Allowance for loan losses (3,332) $ (3,271) (3,874) $ (3,714) $ (3,901) $ (2,168)
Total loans receivable 143,624   116,115      
Loans at fair value 12,104   13,625      
Amortized cost [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 129,358   103,565      
Allowance for loan losses (3,332)   (3,874)      
Total loans receivable 126,026   99,691      
Fair Value [Member]            
Loans Receivable [Line Items]            
Total loans receivable 12,104   13,625      
Loans at fair value 12,104   13,625      
Held for sale [Member]            
Loans Receivable [Line Items]            
Total loans receivable 5,494   2,799      
Loans held for sale 5,494   2,799      
Corporate [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 54,107   48,659      
Loans at fair value 3,020   2,751      
Corporate [Member] | Amortized cost [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 48,943   44,778      
Corporate [Member] | Fair Value [Member]            
Loans Receivable [Line Items]            
Loans at fair value 3,020   2,751      
Corporate [Member] | Held for sale [Member]            
Loans Receivable [Line Items]            
Loans held for sale 2,144   1,130      
Wealth management [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 41,775   33,023      
Loans at fair value 6,616   7,872      
Wealth management [Member] | Amortized cost [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 35,159   25,151      
Wealth management [Member] | Fair Value [Member]            
Loans Receivable [Line Items]            
Loans at fair value 6,616   7,872      
Commercial real estate [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 21,707   20,290      
Loans at fair value 1,655   1,961      
Commercial real estate [Member] | Amortized cost [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 17,892   17,096      
Commercial real estate [Member] | Fair Value [Member]            
Loans Receivable [Line Items]            
Loans at fair value 1,655   1,961      
Commercial real estate [Member] | Held for sale [Member]            
Loans Receivable [Line Items]            
Loans held for sale 2,160   1,233      
Residential real estate [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 13,359   5,750      
Loans at fair value 351   494      
Residential real estate [Member] | Amortized cost [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 12,356   5,236      
Residential real estate [Member] | Fair Value [Member]            
Loans Receivable [Line Items]            
Loans at fair value 351   494      
Residential real estate [Member] | Held for sale [Member]            
Loans Receivable [Line Items]            
Loans held for sale 652   20      
Installment [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 3,449   3,823      
Installment [Member] | Amortized cost [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 3,449   3,823      
Credit card [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 6,251   4,270      
Credit card [Member] | Amortized cost [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 6,251   4,270      
Other Loans [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 6,308   4,174      
Loans at fair value 462   547      
Other Loans [Member] | Amortized cost [Member]            
Loans Receivable [Line Items]            
Gross loans receivable 5,308   3,211      
Other Loans [Member] | Fair Value [Member]            
Loans Receivable [Line Items]            
Loans at fair value 462   547      
Other Loans [Member] | Held for sale [Member]            
Loans Receivable [Line Items]            
Loans held for sale $ 538   $ 416