Loans and Allowance for Credit Losses (Details 4) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 211,919	$ 209,835
Total outstanding commitments	429,391	423,565
Commercial Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	58,789	56,648
Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	36,102	35,851
Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	38,441	37,082
Credit Card [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	16,572	17,360
Other Retail [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	47,837	48,107
Total Loans, Excluding Covered Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	197,741	195,048
Covered Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	14,178	14,787
Pass Internal Credit Rating [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	201,873	199,091
Total outstanding commitments	417,052	410,457
Pass Internal Credit Rating [Member] | Commercial Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	56,211	54,003
Pass Internal Credit Rating [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	31,500	30,733
Pass Internal Credit Rating [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	37,226	35,814
Pass Internal Credit Rating [Member] | Credit Card [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	16,144	16,910
Pass Internal Credit Rating [Member] | Other Retail [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	47,444	47,665
Pass Internal Credit Rating [Member] | Total Loans, Excluding Covered Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	188,525	185,125
Pass Internal Credit Rating [Member] | Covered Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	13,348	13,966
Special Mention Criticized Internal Credit Rating [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,091	2,070
Total outstanding commitments	3,306	3,418
Special Mention Criticized Internal Credit Rating [Member] | Commercial Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,118	1,047
Special Mention Criticized Internal Credit Rating [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	756	793
Special Mention Criticized Internal Credit Rating [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	19	19
Special Mention Criticized Internal Credit Rating [Member] | Other Retail [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	31	24
Special Mention Criticized Internal Credit Rating [Member] | Total Loans, Excluding Covered Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,924	1,883
Special Mention Criticized Internal Credit Rating [Member] | Covered Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	167	187
Classified Criticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,955	8,674
Total outstanding commitments	9,033	9,690
Classified Criticized [Member] | Commercial Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,460	1,598
Classified Criticized [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,846	4,325
Classified Criticized [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,196	1,249
Classified Criticized [Member] | Credit Card [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	428	450
Classified Criticized [Member] | Other Retail [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	362	418
Classified Criticized [Member] | Total Loans, Excluding Covered Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,292	8,040
Classified Criticized [Member] | Covered Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	663	634
Total Criticized [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	10,046	10,744
Total outstanding commitments	12,339	13,108
Total Criticized [Member] | Commercial Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,578	2,645
Total Criticized [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,602	5,118
Total Criticized [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,215	1,268
Total Criticized [Member] | Credit Card [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	428	450
Total Criticized [Member] | Other Retail [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	393	442
Total Criticized [Member] | Total Loans, Excluding Covered Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,216	9,923
Total Criticized [Member] | Covered Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 830	$ 821