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	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative gain recognized in income	$ 68	$ 55
Interest rate contracts | Other noninterest income
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative gain recognized in income	25	16
Energy contracts | Other noninterest income
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative gain recognized in income	2	2
Foreign exchange contracts | Foreign exchange income
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative gain recognized in income	$ 41	$ 37