Asset Quality (Summary of TDRs) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Troubled debt restructurings (TDRs)	$ 2,667	$ 2,739
Nonperforming [Member]
Troubled debt restructurings (TDRs)	1,369	1,511
Accruing [Member]
Troubled debt restructurings (TDRs)	1,153	1,062
Credit Card [Member]
Troubled debt restructurings (TDRs)	145	166
Total commercial lending [Member]
Troubled debt restructurings (TDRs)	546	578
Total consumer lending [Member]
Troubled debt restructurings (TDRs)	$ 2,121	$ 2,161