Loans and ACL (Summary of the primary reason loan modifications were classified as TDRs) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Commercial and Industrial, Excluding Covered [Member]
Summary Of Reason Modifications Were Considered TDRs
TDR rate modification	$ 99	$ 51	$ 29
TDR structure modification	27	63	68
TDR increase to allowance	3	0	5
CRE - Other, Excluding Covered [Member]
Summary Of Reason Modifications Were Considered TDRs
TDR rate modification	62	67	56
TDR structure modification	54	45	58
TDR increase to allowance	1	0	8
CRE - Residential ADC, Excluding Covered [Member]
Summary Of Reason Modifications Were Considered TDRs
TDR rate modification	22	44	29
TDR structure modification	10	34	47
TDR increase to allowance	(2)	(1)	10
Commercial Other Lending Subsidiaries, Excluding Covered [Member]
Summary Of Reason Modifications Were Considered TDRs
TDR rate modification	0	0	1
TDR structure modification	0	0	1
TDR increase to allowance	0	0	0
Direct Retail Lending, Excluding Covered [Member]
Summary Of Reason Modifications Were Considered TDRs
TDR rate modification	45	120	51
TDR structure modification	9	17	5
TDR increase to allowance	7	35	9
Retail Revolving Credit, Excluding Covered [Member]
Summary Of Reason Modifications Were Considered TDRs
TDR rate modification	26	30	40
TDR structure modification	0	0	0
TDR increase to allowance	4	5	8
Retail Residential Mortgage, Excluding Covered [Member]
Summary Of Reason Modifications Were Considered TDRs
TDR rate modification	103	241	142
TDR structure modification	68	88	35
TDR increase to allowance	11	22	17
Retail Sales Finance, Excluding Covered [Member]
Summary Of Reason Modifications Were Considered TDRs
TDR rate modification	4	16	5
TDR structure modification	7	0	5
TDR increase to allowance	3	4	1
Retail Other Lending Subsidiaries, Excluding Covered [Member]
Summary Of Reason Modifications Were Considered TDRs
TDR rate modification	167	123	37
TDR structure modification	0	2	7
TDR increase to allowance	$ 34	$ 35	$ 15