Allowance for Credit Losses (Breakdown of Allowance for Loan and Lease Losses Based on Method for Determining Allowance) (Details) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010
Individually Evaluated For Impairment	$ 508	$ 456
Collectively Evaluated For Impairment	1,894	2,162
Loans Acquired With Deteriorated Credit Quality	114	90
Total	2,516	2,708	2,723
Commercial and Industrial [Member]
Individually Evaluated For Impairment	108	96
Collectively Evaluated For Impairment	366	525
Loans Acquired With Deteriorated Credit Quality
Total	474	621
Commercial Real Estate - Other [Member]
Individually Evaluated For Impairment	93	63
Collectively Evaluated For Impairment	369	383
Loans Acquired With Deteriorated Credit Quality
Total	462	446
Commercial Real Estate - Residential ADC [Member]
Individually Evaluated For Impairment	82	75
Collectively Evaluated For Impairment	300	394
Loans Acquired With Deteriorated Credit Quality
Total	382	469
Commercial Specialized Lending [Member]
Individually Evaluated For Impairment	1	1
Collectively Evaluated For Impairment	12	20
Loans Acquired With Deteriorated Credit Quality
Total	13	21
Direct Retail Lending [Member]
Individually Evaluated For Impairment	32	26
Collectively Evaluated For Impairment	201	220
Loans Acquired With Deteriorated Credit Quality
Total	233	246
Retail Revolving Credit [Member]
Individually Evaluated For Impairment	26	25
Collectively Evaluated For Impairment	77	84
Loans Acquired With Deteriorated Credit Quality
Total	103	109
Retail Residential Mortgage [Member]
Individually Evaluated For Impairment	148	167
Collectively Evaluated For Impairment	199	131
Loans Acquired With Deteriorated Credit Quality
Total	347	298
Retail Sales Finance [Member]
Individually Evaluated For Impairment	1	1
Collectively Evaluated For Impairment	41	46
Loans Acquired With Deteriorated Credit Quality
Total	42	47
Retail Specialized Lending [Member]
Individually Evaluated For Impairment	17	2
Collectively Evaluated For Impairment	154	175
Loans Acquired With Deteriorated Credit Quality
Total	171	177
Covered and Other Acquired [Member]
Individually Evaluated For Impairment
Collectively Evaluated For Impairment	45	54
Loans Acquired With Deteriorated Credit Quality	114	90
Total	159	144
Unallocated [Member]
Individually Evaluated For Impairment
Collectively Evaluated For Impairment	130	130
Loans Acquired With Deteriorated Credit Quality
Total	$ 130	$ 130