Investment Securities (Gains And Losses, Including OTTI, Recognized In Statement Of Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investments [Abstract]
Equity securities gains (losses)	$ 1	$ 14	$ 7
Investment securities, Available-for-sale, Gross gains	0	0	0
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities	0	0	0
Other noninterest-bearing investments, Nonmarketable equity securities, Gross gains	17	22	21
Other noninterest-bearing investments, Nonmarketable equity securities, Gross losses	16	8	14
Total investment securities and other noninterest-bearing investments, Gross gains	17	22	21
Total investment securities and other noninterest-bearing investments, Gross losses	16	8	14
Net losses	1	14	7
Fixed income securities gains (losses), net	$ 0	$ 0	$ 0