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, 2018	Dec. 31, 2017
Derivative [Line Items]
Total derivatives, Notional amount	$ 7,481	$ 6,824
Amount of derivative gain (loss), recognized in OCI	(1)	(8)
Amount of derivative gain (loss), Reclassified from AOCI to interest income	(4)	4
Derivatives instruments, Noninterest income (expense)	31	27
Derivatives designated as hedging instruments, Offset to interest expense	(1)	0
Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	45	38
Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	39	40
Derivatives Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivatives, Notional amount	1,187	1,138
Amount of derivative gain (loss), recognized in OCI	(1)	(8)
Amount of derivative gain (loss), Reclassified from AOCI to interest income	(4)	4
Derivatives designated as hedging instruments, Offset to interest expense	(1)	0
Derivatives Designated As Hedging Instruments [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	0	0
Derivatives Designated As Hedging Instruments [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	0	0
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Total derivatives, Notional amount	687	1,138
Amount of derivative gain (loss), recognized in OCI	(1)	(8)
Amount of derivative gain (loss), Reclassified from AOCI to interest income	(4)	4
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Total derivatives, Notional amount	500	0
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Assets [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	0	0
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Assets [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	0	0
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Liabilities [Member] | Cash Flow Hedges [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	0	0
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Liabilities [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	0	0
Derivatives Designated As Hedging Instruments [Member] | Terminated Swaps On Long Term Debt [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Derivatives designated as hedging instruments, Offset to interest expense	(1)	0
Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivatives, Notional amount	6,294	5,686
Derivatives Not Designated As Hedging Instruments [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	45	38
Derivatives Not Designated As Hedging Instruments [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	39	40
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Total derivatives, Notional amount	253	223
Derivatives instruments, Noninterest income (expense)	(1)	(1)
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	1	1
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	1	0
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member]
Derivative [Line Items]
Total derivatives, Notional amount	5,652	4,550
Derivatives instruments, Noninterest income (expense)	14	11
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	40	28
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	36	33
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange [Member]
Derivative [Line Items]
Total derivatives, Notional amount	389	913
Derivatives instruments, Noninterest income (expense)	18	17
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	4	9
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	$ 2	$ 7