Derivative And Credit-Related Financial Instruments (Schedule Of Net Gains Recognized In Income On Customer-Initiated Derivatives) (Details) - Customer-initiated and other activities - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative gain recognized in income	$ 10	$ 16	$ 49	$ 53
Interest rate contracts | Other noninterest income
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative gain recognized in income	1	4	17	16
Energy contracts | Other noninterest income
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative gain recognized in income	0	1	3	4
Foreign exchange contracts | Foreign exchange income
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative gain recognized in income	$ 9	$ 11	$ 29	$ 33