Asset Quality (Nonperforming Assets) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Nonperforming loans	$ 2,801	$ 3,088
OREO and Foreclosed Assets	367	369
Total nonperforming assets	3,168	3,457
Nonperforming loans to total loans	1.39%	1.58%
Nonperforming assets to total loans, OREO and foreclosed assets	1.57%	1.76%
Nonperforming assets to total assets	0.97%	1.08%
Exclusions from OREO	228	245
Total commercial lending [Member]
Nonperforming loans	833	980
Total consumer lending [Member]
Nonperforming loans	1,968	2,108
Commercial [Member]
Nonperforming loans	394	457
Commercial [Member] | Total commercial lending [Member]
Nonperforming loans	394	457
Commercial Real Estate [Member]
Nonperforming loans	435	518
Commercial Real Estate [Member] | Total commercial lending [Member]
Nonperforming loans	435	518
Equipment Lease Financing [Member]
Nonperforming loans	4	5
Equipment Lease Financing [Member] | Total commercial lending [Member]
Nonperforming loans	4	5
Home Equity [Member]
Nonperforming loans	1,093	1,139
Home Equity [Member] | Total consumer lending [Member]
Nonperforming loans	1,093	1,139
Residential Real Estate [Member]
Nonperforming loans	816	904
Residential Real Estate [Member] | Total consumer lending [Member]
Nonperforming loans	816	904
Credit Card [Member]
Nonperforming loans	3	4
Credit Card [Member] | Total consumer lending [Member]
Nonperforming loans	3	4
Other Consumer [Member]
Nonperforming loans	56	61
Other Consumer [Member] | Total consumer lending [Member]
Nonperforming loans	56	61
OREO [Member]
OREO and Foreclosed Assets	352	360
Foreclosed and Other Assets [Member]
OREO and Foreclosed Assets	$ 15	$ 9