Loans and ACL (Summary of Loans Collectively Evaluated for Impairment) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Recorded Investment, Collectively evaluated for impairment	$ 113,405	$ 111,856
Related ALLL, Collectively evaluated for impairment	1,365	1,607
Commercial and Industrial, Excluding Covered [Member]
Recorded Investment, Collectively evaluated for impairment	38,042	37,664
Related ALLL, Collectively evaluated for impairment	382	397
CRE - Other, Excluding Covered [Member]
Recorded Investment, Collectively evaluated for impairment	11,441	11,149
Related ALLL, Collectively evaluated for impairment	150	168
CRE - Residential ADC, Excluding Covered [Member]
Recorded Investment, Collectively evaluated for impairment	881	1,106
Related ALLL, Collectively evaluated for impairment	38	79
Commercial Other Lending Subsidiaries, Excluding Covered [Member]
Recorded Investment, Collectively evaluated for impairment	4,501	4,135
Related ALLL, Collectively evaluated for impairment	15	12
Direct Retail Lending, Excluding Covered [Member]
Recorded Investment, Collectively evaluated for impairment	15,648	15,582
Related ALLL, Collectively evaluated for impairment	166	241
Retail Revolving Credit, Excluding Covered [Member]
Recorded Investment, Collectively evaluated for impairment	2,355	2,274
Related ALLL, Collectively evaluated for impairment	96	78
Retail Residential Mortgage, Excluding Covered [Member]
Recorded Investment, Collectively evaluated for impairment	23,316	23,085
Related ALLL, Collectively evaluated for impairment	167	198
Retail Sales Finance, Excluding Covered [Member]
Recorded Investment, Collectively evaluated for impairment	9,363	7,714
Related ALLL, Collectively evaluated for impairment	41	23
Retail Other Lending Subsidiaries, Excluding Covered [Member]
Recorded Investment, Collectively evaluated for impairment	5,823	5,853
Related ALLL, Collectively evaluated for impairment	196	203
Covered [Member]
Recorded Investment, Collectively evaluated for impairment	2,035	3,294
Related ALLL, Collectively evaluated for impairment	114	128
Unallocated [Member]
Related ALLL, Collectively evaluated for impairment	$ 0	$ 80