v3.20.4
Fair Value Option - Additional Information (Detail)
$ in Millions
12 Months Ended
Dec. 31, 2020
USD ($)
yr
Dec. 31, 2019
USD ($)
yr
Dec. 31, 2018
USD ($)
Fair Value [Line Items]      
Total contractual amount of unfunded commitments for which the fair value option was elected $ 1,640 $ 1,550  
Net Gains (Losses) Attributable to the Impact of Changes in Instrument-Specific Credit Spreads on Loans and Lending Commitments For Which the Fair Value Option Was Elected (106) 134 $ 211
Unsecured Long-Term Borrowings at Fair Value [Member]      
Fair Value [Line Items]      
Difference between aggregate contractual principal amount of long-term debt instruments for which the fair value option was elected and related fair value $ 445 $ 199  
Minimum [Member] | Other Secured Financings at Fair Value [Member] | Level 3 [Member] | Fair Value Unobservable Inputs, Yield [Member]      
Fair Value [Line Items]      
Other secured financing measurement input 0.014 0.033  
Minimum [Member] | Other Secured Financings at Fair Value [Member] | Level 3 [Member] | Fair Value Unobservable Inputs, Duration [Member]      
Fair Value [Line Items]      
Other secured financing measurement input | yr 1.4 0.6  
Maximum [Member] | Other Secured Financings at Fair Value [Member] | Level 3 [Member] | Fair Value Unobservable Inputs, Yield [Member]      
Fair Value [Line Items]      
Other secured financing measurement input 0.071 0.042  
Maximum [Member] | Other Secured Financings at Fair Value [Member] | Level 3 [Member] | Fair Value Unobservable Inputs, Duration [Member]      
Fair Value [Line Items]      
Other secured financing measurement input | yr 8.0 2.1  
Weighted Average [Member] | Other Secured Financings at Fair Value [Member] | Level 3 [Member] | Fair Value Unobservable Inputs, Yield [Member]      
Fair Value [Line Items]      
Other secured financing measurement input 0.027 0.035  
Weighted Average [Member] | Other Secured Financings at Fair Value [Member] | Level 3 [Member] | Fair Value Unobservable Inputs, Duration [Member]      
Fair Value [Line Items]      
Other secured financing measurement input | yr 4.0 1.0  
Other Financial Liabilities [Member]      
Fair Value [Line Items]      
Gains/(Losses) on liabilities $ (1,620) $ (2,590)  
Realized Gains/(Losses) on liabilities   (337)  
Net Unrealized Gains / (Losses)   (2,250)  
Fair Value, Measured on Recurring Basis, Gains/(Losses) Included in condensed consolidated statements of earnings (317) (337)  
Fair Value, Measured on Recurring Basis, Gains/(Losses) Included in condensed consolidated statements of comprehensive income (1,301) (2,254)  
Other Financial Liabilities [Member] | Unsecured Long-Term Borrowings at Fair Value [Member]      
Fair Value [Line Items]      
Fair Value, Measured on Recurring Basis, Gains/(Losses) Included in condensed consolidated statements of earnings (229) (278)  
Fair Value, Measured on Recurring Basis, Gains/(Losses) Included in condensed consolidated statements of comprehensive income (510) (1,223)  
Other Financial Liabilities [Member] | Other Secured Financings at Fair Value [Member]      
Fair Value [Line Items]      
Fair Value, Measured on Recurring Basis, Gains/(Losses) Included in condensed consolidated statements of earnings 13 36  
Fair Value, Measured on Recurring Basis, Gains/(Losses) Included in condensed consolidated statements of comprehensive income (142) (52)  
Other Financial Liabilities [Member] | Debt Valuation Adjustment [Member]      
Fair Value [Line Items]      
Fair Value, Measured on Recurring Basis, Gains/(Losses) Included in condensed consolidated statements of comprehensive income 139 595  
Other Financial Liabilities [Member] | Market making [Member]      
Fair Value [Line Items]      
Fair Value, Measured on Recurring Basis, Gains/(Losses) Included in condensed consolidated statements of earnings (1,440) (1,980)  
Other Financial Liabilities [Member] | Other Principal Transactions [Member]      
Fair Value [Line Items]      
Fair Value, Measured on Recurring Basis, Gains/(Losses) Included in condensed consolidated statements of earnings (28) (10)  
Other Financial Liabilities [Member] | Interest Expense [Member]      
Fair Value [Line Items]      
Fair Value, Measured on Recurring Basis, Gains/(Losses) Included in condensed consolidated statements of earnings (15) (9)  
Written Loan Commitment, Fair Value Option [Member]      
Fair Value [Line Items]      
Fair value of unfunded commitments for which the fair value option was elected $ 25 $ 24