v3.19.3.a.u2
Derivative Financial Instruments And Hedging Activities (Schedule Of Derivative Instruments Notional And Fair Values) (Details) - USD ($)
$ in Millions
Dec. 31, 2019
Dec. 31, 2018
Derivatives, Fair Value [Line Items]    
Derivative Notional Amount 1 $ 143,922 $ 87,394
Estimated Fair Value, Gain 669 370
Estimated Fair Value, Loss 242 340
Derivative Asset, Fair Value of Derivative Contracts Offset in Accordance with Entity's Policy that were Offset Under Master Netting Agreements 105 108
Derivative Liability, Fair Value of Derivative Contracts Offset In Accordance with Policy Election that were Offset Under Master Netting Agreements 105 108
Derivative Asset, Collateral, Obligation to Return Cash, Offset 229 135
Derivative Liability, Collateral, Right to Reclaim Cash, Offset 90 71
Derivative Asset 335 127
Derivative Liability 47 161
Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Notional Amount 1 26,900 15,231
Estimated Fair Value, Gain 208 72
Not Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Notional Amount 1 117,022 72,163
Estimated Fair Value, Gain 461 298
Estimated Fair Value, Loss 242 340
Interest Rate Swaps [Member] | Not Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Notional Amount 1 68,075 49,737
Interest Rate Swaps [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]    
Derivatives, Fair Value [Line Items]    
Estimated Fair Value, Gain 376 193
Interest Rate Swaps [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Estimated Fair Value, Loss 164 237
Interest Rate Options [Member] | Not Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Notional Amount 1 11,347 7,178
Interest Rate Options [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]    
Derivatives, Fair Value [Line Items]    
Estimated Fair Value, Gain 27 29
Interest Rate Options [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Estimated Fair Value, Loss 9 20
Interest Rate Futures And Forward Commitments [Member] | Not Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Notional Amount 1 27,324 7,961
Interest Rate Futures And Forward Commitments [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]    
Derivatives, Fair Value [Line Items]    
Estimated Fair Value, Gain 10 4
Interest Rate Futures And Forward Commitments [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Estimated Fair Value, Loss 11 9
Other Contract [Member] | Not Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Notional Amount 1 10,276 7,287
Other Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]    
Derivatives, Fair Value [Line Items]    
Estimated Fair Value, Gain 48 72
Other Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member]    
Derivatives, Fair Value [Line Items]    
Estimated Fair Value, Loss 58 74
Fair Value Hedging [Member] | Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Notional Amount 1 2,900 3,231
Cash Flow Hedging [Member] | Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Notional Amount 1 17,250 8,750
Cash Flow Hedging [Member] | Interest Rate Floor [Member] | Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Derivative Notional Amount 1 6,750 3,250
Cash Flow Hedging [Member] | Interest Rate Floor [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]    
Derivatives, Fair Value [Line Items]    
Estimated Fair Value, Gain $ 208 $ 72