Derivative Instruments And Hedging Activities (Schedule Of Notional Amounts And Recorded Gross Fair Values And Related Gain (Loss) Of Derivative Instruments) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Other Assets [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 158	$ 75
Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	167	76
Other Debt Obligations [Member]
Derivative [Line Items]
Derivative, Notional Amount	15,030	7,528
Designated As Hedging Instruments [Member]
Derivative [Line Items]
Derivative, Notional Amount	5,088	1,187
Amount of derivative gain (loss), recognized in OCI	47	5
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), Adjustments, before Tax	27	0
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(4)	2
Derivative Instrument, Noninterest Income (Expense)	3	1
Gain (Loss) on Discontinuation of Interest Rate Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net	0	0
Designated As Hedging Instruments [Member] \| Interest Rate Swaps [Member] \| Fair Value Hedging [Member]
Derivative [Line Items]
Derivative, Notional Amount	1,500	500
Designated As Hedging Instruments [Member] \| Interest Rate Swaps [Member] \| Cash Flow Hedges [Member]
Derivative [Line Items]
Derivative, Notional Amount	3,588	687
Designated As Hedging Instruments [Member] \| Interest Rate Swaps [Member] \| Other Assets [Member] \| Cash Flow Hedges [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	0
Designated As Hedging Instruments [Member] \| Interest Rate Swaps [Member] \| Other Liabilities [Member] \| Cash Flow Hedges [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	0
Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Derivative, Notional Amount	9,942	6,341
Not Designated As Hedging Instruments [Member] \| Other Assets [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	158	75
Not Designated As Hedging Instruments [Member] \| Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	167	76
Not Designated As Hedging Instruments [Member] \| Interest Rate Swaps [Member]
Derivative [Line Items]
Derivative, Notional Amount	726	300
Not Designated As Hedging Instruments [Member] \| Interest Rate Swaps [Member] \| Other Assets [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	3	1
Not Designated As Hedging Instruments [Member] \| Interest Rate Swaps [Member] \| Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	1	1
Not Designated As Hedging Instruments [Member] \| Foreign Exchange [Member]
Derivative [Line Items]
Derivative, Notional Amount	385	389
Not Designated As Hedging Instruments [Member] \| Foreign Exchange [Member] \| Other Assets [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	4	4
Not Designated As Hedging Instruments [Member] \| Foreign Exchange [Member] \| Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	4	2
Not Designated As Hedging Instruments [Member] \| Interest Rate Swaps For Customers [Member]
Derivative [Line Items]
Derivative, Notional Amount	4,409	2,826
Not Designated As Hedging Instruments [Member] \| Interest Rate Swaps For Customers [Member] \| Other Assets [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	146	37
Not Designated As Hedging Instruments [Member] \| Interest Rate Swaps For Customers [Member] \| Other Assets [Member] \| Fair Value Hedging [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	141	7
Not Designated As Hedging Instruments [Member] \| Interest Rate Swaps For Customers [Member] \| Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	5	33
Not Designated As Hedging Instruments [Member] \| Interest Rate Swaps For Customers [Member] \| Other Liabilities [Member] \| Fair Value Hedging [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	5	33
Not Designated As Hedging Instruments [Member] \| Offsetting Interest Rate Derivatives [Member]
Derivative [Line Items]
Derivative, Notional Amount	4,422	2,826
Not Designated As Hedging Instruments [Member] \| Offsetting Interest Rate Derivatives [Member] \| Other Assets [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	5	33
Not Designated As Hedging Instruments [Member] \| Offsetting Interest Rate Derivatives [Member] \| Other Assets [Member] \| Fair Value Hedging [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	5	33
Not Designated As Hedging Instruments [Member] \| Offsetting Interest Rate Derivatives [Member] \| Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	157	40
Not Designated As Hedging Instruments [Member] \| Offsetting Interest Rate Derivatives [Member] \| Other Liabilities [Member] \| Fair Value Hedging [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ 9	$ 3

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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Amount, before tax, of adjustments from accumulated other comprehensive income (AOCI) for gain (loss) from increase (decrease) in value of excluded component of derivative designated and qualifying as hedge. Adjustments include, but are not limited to, reclassifications for sale and settlement, and amounts recognized under systematic and rational method.

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Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Derivative instrument noninterest income (expense)

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