Derivative And Credit-Related Financial Instruments (Schedule Of Financial Instruments With Off-Balance Sheet Credit Risk) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Unused Commitments to Extend Credit
Loss contingency, range of possible loss, maximum	$ 28,529	$ 30,056
Commercial And Other | Unused Commitments to Extend Credit
Loss contingency, range of possible loss, maximum	26,115	27,905
Bankcard, Revolving Check Credit And Home Equity Loan Commitments | Unused Commitments to Extend Credit
Loss contingency, range of possible loss, maximum	2,414	2,151
Standby Letters Of Credit
Loss contingency, range of possible loss, maximum	3,985	3,880
Commercial Letters Of Credit
Loss contingency, range of possible loss, maximum	$ 41	$ 75