Other Operating Expenses (Schedule Of Other Operating Expenses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Expenses [Abstract]
Insurance Commissions	$ 415	$ 389	$ 378
Communications and Information Technology	284	274	267
Lease And Loan Administration	159	136	126
Marketing and Advertising Expense	133	112	107
Professional Fees	113	103	93
Federal Deposit Insurance Corporation Premium Expense	113	94	79
Vehicle remarketing and repossession	110	95	78
Depreciation, Nonproduction	89	84	82
Occupancy, Net	46	51	50
Taxes, Miscellaneous	21	25	29
Other Cost and Expense, Operating	200	242	216
Other Noninterest Expense	$ 1,683	$ 1,605	$ 1,505