Loans and Allowance for Credit Losses (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Commercial
Commercial	$ 53,035	$ 50,734
Commercial	25.00%	24.20%
Lease financing	5,754	5,914
Lease financing	2.70%	2.80%
Total commercial	58,789	56,648
Total commercial	27.70%	27.00%
Commercial Real Estate
Commercial mortgages	30,215	29,664
Commercial mortgages	14.20%	14.10%
Construction and development	5,887	6,187
Construction and development	2.80%	3.00%
Total commercial real estate	36,102	35,851
Total commercial real estate	17.00%	17.10%
Residential Mortgages
Residential Mortgages	29,610	28,669
Residential mortgages	14.00%	13.70%
Home equity loans, first liens	8,831	8,413
Home equity loans, first liens	4.20%	4.00%
Total residential mortgages	38,441	37,082
Total residential mortgages	18.20%	17.70%
Credit card	16,572	17,360
Credit card	7.80%	8.30%
Other Retail
Retail leasing	5,125	5,118
Retail leasing	2.40%	2.40%
Home equity and second mortgages	17,697	18,131
Home equity and second mortgages	8.40%	8.60%
Revolving credit	3,230	3,344
Revolving Credit	1.50%	1.60%
Installment	5,321	5,348
Installment	2.50%	2.60%
Automobile	11,907	11,508
Automobile	5.60%	5.50%
Student	4,557	4,658
Student	2.20%	2.20%
Total other retail	47,837	48,107
Total other retail	22.60%	22.90%
Total loans, excluding covered loans	197,741	195,048
Total loans, excluding covered loans	93.30%	93.00%
Covered loans	14,178	14,787
Covered loans	6.70%	7.00%
Total loans	$ 211,919	$ 209,835
Total loans	100.00%	100.00%