v3.20.4
Loans - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Loans Receivable [Line Items]      
Gains/(Losses) as a result of changes in the fair value $ (3,161) $ (9,499) $ 2,677
Impaired loans receivable (excluding PCI loans) on non-accrual status $ 3,552 $ 1,530  
Allowance for loan losses as a percentage of total gross loans receivable 3.70% 1.60%  
Percentage of loans that were rated pass/non-criticized 85.00% 91.00%  
Change in allowance for credit losses $ 2,630 $ 450  
Loans $ 119,989 $ 110,345  
Concentration Risk,Percentage 100.00% 100.00%  
Gs Unrated [Member]      
Loans Receivable [Line Items]      
Loans $ 9,730 $ 9,540  
COVID 19 [Member]      
Loans Receivable [Line Items]      
CARES Act/Interagency TDR relief 184    
PCI Loans [Member]      
Loans Receivable [Line Items]      
Loans accounted for at amortized cost included PCI loans, carrying value   1,620  
Loans accounted for at amortized cost included PCI loans, outstanding principal balance   3,230  
Loans accounted for at amortized cost included PCI loans, accretable yield   220  
Loans   1,622  
Financial Asset, Equal to or Greater than 30 Days Past Due [Member]      
Loans Receivable [Line Items]      
Impaired loans receivable (excluding PCI loans) on non-accrual status $ 533 $ 429  
Wholesale [Member]      
Loans Receivable [Line Items]      
Allowance for loan losses as a percentage of total gross loans receivable 2.70% 1.10%  
Nonaccrual loans, for which allowance for credit losses was measured $ 3,510 $ 1,490  
Nonaccrual loans, allowance for credit losses 649 207  
Nonaccrual loans, for which no allowance for credit losses required 584 754  
Loans $ 103,565 $ 90,636  
Consumer [Member]      
Loans Receivable [Line Items]      
Allowance for loan losses as a percentage of total gross loans receivable 15.90% 6.00%  
Other Principal Transactions [Member]      
Loans Receivable [Line Items]      
Gains/(Losses) as a result of changes in the fair value $ 151 $ 355  
Installment And Credit Card Receivables [Member] | Gs Unrated [Member]      
Loans Receivable [Line Items]      
Loans 8,090 6,610  
Corporate And Commercial Real Estate Loans [Member]      
Loans Receivable [Line Items]      
Loans modified in troubled debt restructuring $ 315 $ 251  
Diversified Industrials [Member]      
Loans Receivable [Line Items]      
Concentration Risk,Percentage 17.00% 17.00%  
Technology Media Telecommunications [Member]      
Loans Receivable [Line Items]      
Concentration Risk,Percentage 17.00% 17.00%  
Funds [Member]      
Loans Receivable [Line Items]      
Concentration Risk,Percentage 13.00% 9.00%  
Natural Resources Utilities [Member]      
Loans Receivable [Line Items]      
Concentration Risk,Percentage 12.00% 12.00%  
Financial Institutions [Member]      
Loans Receivable [Line Items]      
Concentration Risk,Percentage 10.00% 10.00%  
Level 3 [Member]      
Loans Receivable [Line Items]      
Net gains / (losses) on assets $ 159 $ 131  
Level 3 [Member] | Interest Income [Member]      
Loans Receivable [Line Items]      
Net gains / (losses) on assets 24 33  
Level 3 [Member] | Loans Non Trading [Member]      
Loans Receivable [Line Items]      
Net unrealized gains / (losses) on assets 87 85  
Net realized gains / (losses) on assets 72 46  
Level 3 [Member] | Other Principal Transactions [Member]      
Loans Receivable [Line Items]      
Net gains / (losses) on assets $ 135 $ 98