v3.19.3.a.u2
Derivative Financial Instruments And Hedging Activities (Narrative) (Details) - USD ($)
$ in Millions
12 Months Ended
Feb. 20, 2020
Dec. 31, 2019
Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Pledged Assets Separately Reported, Securities Pledged as Collateral, at Fair Value   $ 8,300 $ 7,900
Terminated Cash Flow Hedge Unrealized Gain (Loss) To Be Reclassified From OCI, After Tax Amount   58 51
Pre Tax Income (Loss) Related to Amortization of Cash Flow Hedges   14 45
Cash flow hedge expected to be reclassified from other comprehensive income into earnings within the next 12 months   (50)  
Pre-tax net income related to amortization of discontinued cash flow hedges   $ 9  
Maximum Length of Time Hedged in Cash Flow Hedge   7 years  
Maximum potential future exposure on swap participations   $ 592  
Aggregate fair value of all derivative instruments with credit risk   64 45
Posted collateral related to derivative instruments with credit risk   67 43
Derivative Notional Amount 1   143,922 87,394
Not Designated as Hedging Instrument [Member]      
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Derivative Notional Amount 1   117,022 72,163
Interest Rate Lock Commitments [Member] | Not Designated as Hedging Instrument [Member]      
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Derivative Notional Amount 1   366 191
Forward Sale Commitments [Member] | Not Designated as Hedging Instrument [Member]      
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Derivative Notional Amount 1   662 429
Forward Rate Commitments and Futures Contracts [Member] | Not Designated as Hedging Instrument [Member]      
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Derivative Notional Amount 1   4,800 5,700
US Treasury Securities [Member]      
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Pledged Assets Separately Reported, Securities Pledged as Collateral, at Fair Value   24 24
Debt Available-for-Sale Securities [Member] | Not Designated as Hedging Instrument [Member]      
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Hedged Asset, Fair Value Hedge   337 604
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)   3 $ 4
Long-term Debt [Member] | Not Designated as Hedging Instrument [Member]      
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)   $ 2  
Subsequent Event [Member]      
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Terminated hedges $ 1,250