Loans and ACL (Commercial Credit Exposure Credit Risk Profile by Internal Loan Risk Rating) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Loans and leases	$ 115,917	$ 114,603
Commercial and Industrial, Excluding Covered [Member]
Loans and leases	38,508	38,295
Commercial and Industrial, Excluding Covered [Member] | Pass Grade Credit [Member]
Loans and leases	36,804	36,044
Commercial and Industrial, Excluding Covered [Member] | Special Mention Grade Credit [Member]
Loans and leases	219	274
Commercial and Industrial, Excluding Covered [Member] | Substandard Performing [Member]
Loans and leases	1,122	1,431
Commercial and Industrial, Excluding Covered [Member] | Nonperforming [Member]
Loans and leases	363	546
CRE - Other, Excluding Covered [Member]
Loans and leases	11,672	11,461
CRE - Other, Excluding Covered [Member] | Pass Grade Credit [Member]
Loans and leases	10,883	10,095
CRE - Other, Excluding Covered [Member] | Special Mention Grade Credit [Member]
Loans and leases	58	120
CRE - Other, Excluding Covered [Member] | Substandard Performing [Member]
Loans and leases	602	1,034
CRE - Other, Excluding Covered [Member] | Nonperforming [Member]
Loans and leases	129	212
CRE - Residential ADC, Excluding Covered [Member]
Loans and leases	938	1,261
CRE - Residential ADC, Excluding Covered [Member] | Pass Grade Credit [Member]
Loans and leases	794	859
CRE - Residential ADC, Excluding Covered [Member] | Special Mention Grade Credit [Member]
Loans and leases	11	41
CRE - Residential ADC, Excluding Covered [Member] | Substandard Performing [Member]
Loans and leases	98	233
CRE - Residential ADC, Excluding Covered [Member] | Nonperforming [Member]
Loans and leases	35	128
Commercial Other Lending Subsidiaries, Excluding Covered [Member]
Loans and leases	4,502	4,138
Commercial Other Lending Subsidiaries, Excluding Covered [Member] | Pass Grade Credit [Member]
Loans and leases	4,464	4,093
Commercial Other Lending Subsidiaries, Excluding Covered [Member] | Special Mention Grade Credit [Member]
Loans and leases	8	13
Commercial Other Lending Subsidiaries, Excluding Covered [Member] | Substandard Performing [Member]
Loans and leases	29	29
Commercial Other Lending Subsidiaries, Excluding Covered [Member] | Nonperforming [Member]
Loans and leases	$ 1	$ 3