v3.21.2
Trading Cash Instruments - Fair Value, Cash Instruments, Measurement Inputs, Disclosure (Detail)
$ in Millions
Sep. 30, 2021
USD ($)
yr
Jun. 30, 2021
USD ($)
Dec. 31, 2020
USD ($)
yr
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Total financial assets at fair value | $ $ 733,616 $ 668,710 $ 627,073
Level 3 [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Total financial assets at fair value | $ 23,437 $ 25,623 26,305
Level 3 [Member] | Loans and Securities Backed by Commercial Real Estate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Total financial assets at fair value | $ $ 136   $ 203
Level 3 [Member] | Loans and Securities Backed by Commercial Real Estate [Member] | Minimum [Member] | Fair Value Unobservable Inputs, Yield [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.035   0.017
Level 3 [Member] | Loans and Securities Backed by Commercial Real Estate [Member] | Minimum [Member] | Fair Value Unobservable Inputs, Recovery Rate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.079   0.051
Level 3 [Member] | Loans and Securities Backed by Commercial Real Estate [Member] | Minimum [Member] | Fair Value Unobservable Inputs, Duration [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.4   1.1
Level 3 [Member] | Loans and Securities Backed by Commercial Real Estate [Member] | Maximum [Member] | Fair Value Unobservable Inputs, Yield [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.271   0.220
Level 3 [Member] | Loans and Securities Backed by Commercial Real Estate [Member] | Maximum [Member] | Fair Value Unobservable Inputs, Recovery Rate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.970   0.949
Level 3 [Member] | Loans and Securities Backed by Commercial Real Estate [Member] | Maximum [Member] | Fair Value Unobservable Inputs, Duration [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 4.6   9.1
Level 3 [Member] | Loans and Securities Backed by Commercial Real Estate [Member] | Weighted Average [Member] | Fair Value Unobservable Inputs, Yield [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.131   0.090
Level 3 [Member] | Loans and Securities Backed by Commercial Real Estate [Member] | Weighted Average [Member] | Fair Value Unobservable Inputs, Recovery Rate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.617   0.577
Level 3 [Member] | Loans and Securities Backed by Commercial Real Estate [Member] | Weighted Average [Member] | Fair Value Unobservable Inputs, Duration [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 1.9   5.0
Level 3 [Member] | Loans and Securities Backed by Residential Real Estate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Total financial assets at fair value | $ $ 122   $ 131
Level 3 [Member] | Loans and Securities Backed by Residential Real Estate [Member] | Minimum [Member] | Fair Value Unobservable Inputs, Yield [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.010   0.006
Level 3 [Member] | Loans and Securities Backed by Residential Real Estate [Member] | Minimum [Member] | Fair Value Unobservable Inputs, Cumulative Loss Rate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.011   0.034
Level 3 [Member] | Loans and Securities Backed by Residential Real Estate [Member] | Minimum [Member] | Fair Value Unobservable Inputs, Duration [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.2   0.9
Level 3 [Member] | Loans and Securities Backed by Residential Real Estate [Member] | Maximum [Member] | Fair Value Unobservable Inputs, Yield [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.272   0.157
Level 3 [Member] | Loans and Securities Backed by Residential Real Estate [Member] | Maximum [Member] | Fair Value Unobservable Inputs, Cumulative Loss Rate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.375   0.456
Level 3 [Member] | Loans and Securities Backed by Residential Real Estate [Member] | Maximum [Member] | Fair Value Unobservable Inputs, Duration [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 16.6   16.1
Level 3 [Member] | Loans and Securities Backed by Residential Real Estate [Member] | Weighted Average [Member] | Fair Value Unobservable Inputs, Yield [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.089   0.063
Level 3 [Member] | Loans and Securities Backed by Residential Real Estate [Member] | Weighted Average [Member] | Fair Value Unobservable Inputs, Cumulative Loss Rate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.162   0.208
Level 3 [Member] | Loans and Securities Backed by Residential Real Estate [Member] | Weighted Average [Member] | Fair Value Unobservable Inputs, Duration [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 6.6   6.5
Level 3 [Member] | Corporate debt instruments [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Total financial assets at fair value | $ $ 1,096   $ 797
Level 3 [Member] | Corporate debt instruments [Member] | Minimum [Member] | Fair Value Unobservable Inputs, Yield [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.002   0.006
Level 3 [Member] | Corporate debt instruments [Member] | Minimum [Member] | Fair Value Unobservable Inputs, Recovery Rate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.090   0.000
Level 3 [Member] | Corporate debt instruments [Member] | Minimum [Member] | Fair Value Unobservable Inputs, Duration [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 1.5   0.3
Level 3 [Member] | Corporate debt instruments [Member] | Maximum [Member] | Fair Value Unobservable Inputs, Yield [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.155   0.306
Level 3 [Member] | Corporate debt instruments [Member] | Maximum [Member] | Fair Value Unobservable Inputs, Recovery Rate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.800   0.736
Level 3 [Member] | Corporate debt instruments [Member] | Maximum [Member] | Fair Value Unobservable Inputs, Duration [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 28.8   25.5
Level 3 [Member] | Corporate debt instruments [Member] | Weighted Average [Member] | Fair Value Unobservable Inputs, Yield [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.058   0.095
Level 3 [Member] | Corporate debt instruments [Member] | Weighted Average [Member] | Fair Value Unobservable Inputs, Recovery Rate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 0.644   0.587
Level 3 [Member] | Corporate debt instruments [Member] | Weighted Average [Member] | Fair Value Unobservable Inputs, Duration [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Fair Value Unobservable Inputs, Asset 4.7   4.0