Credit Quality And Allowance For Credit Losses (Loans By Credit Quality Indicator) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Total loans	$ 42,679		$ 40,236		$ 42,161
Business Loans [Member]
Total loans	38,868		36,306
Business Loans [Member] | Commercial Loans [Member]
Total loans	24,996		22,145
Business Loans [Member] | Real Estate Construction [Member]
Total loans	1,533		2,253
Business Loans [Member] | Real Estate Construction [Member] | Commercial Real Estate Business Line [Member]
Total loans	1,103	[1]	1,826	[1]
Business Loans [Member] | Real Estate Construction [Member] | Other Business Lines [Member]
Total loans	430	[2]	427	[2]
Business Loans [Member] | Commercial Mortgage [Member]
Total loans	10,264		9,767
Business Loans [Member] | Commercial Mortgage [Member] | Commercial Real Estate Business Line [Member]
Total loans	2,507	[1]	1,937	[1]
Business Loans [Member] | Commercial Mortgage [Member] | Other Business Lines [Member]
Total loans	7,757	[2]	7,830	[2]
Business Loans [Member] | Lease Financing Loan [Member]
Total loans	905		1,009
Business Loans [Member] | International Loan [Member]
Total loans	1,170		1,132
Retail Loans [Member]
Total loans	3,811		3,930
Retail Loans [Member] | Residential Mortgage Loan [Member]
Total loans	1,526		1,619
Retail Loans [Member] | Consumer Loans [Member]
Total loans	2,285		2,311
Retail Loans [Member] | Consumer Loans [Member] | Home Equity [Member]
Total loans	1,655		1,704
Retail Loans [Member] | Consumer Loans [Member] | Other Consumer [Member]
Total loans	630		607
Pass [Member]
Total loans	38,212	[3]	34,694	[3]
Pass [Member] | Business Loans [Member]
Total loans	34,575	[3]	30,916	[3]
Pass [Member] | Business Loans [Member] | Commercial Loans [Member]
Total loans	23,206	[3]	19,884	[3]
Pass [Member] | Business Loans [Member] | Real Estate Construction [Member]
Total loans	1,138	[3]	1,408	[3]
Pass [Member] | Business Loans [Member] | Real Estate Construction [Member] | Commercial Real Estate Business Line [Member]
Total loans	768	[1],[3]	1,025	[1],[3]
Pass [Member] | Business Loans [Member] | Real Estate Construction [Member] | Other Business Lines [Member]
Total loans	370	[2],[3]	383	[2],[3]
Pass [Member] | Business Loans [Member] | Commercial Mortgage [Member]
Total loans	8,269	[3]	7,699	[3]
Pass [Member] | Business Loans [Member] | Commercial Mortgage [Member] | Commercial Real Estate Business Line [Member]
Total loans	1,728	[1],[3]	1,104	[1],[3]
Pass [Member] | Business Loans [Member] | Commercial Mortgage [Member] | Other Business Lines [Member]
Total loans	6,541	[2],[3]	6,595	[2],[3]
Pass [Member] | Business Loans [Member] | Lease Financing Loan [Member]
Total loans	865	[3]	962	[3]
Pass [Member] | Business Loans [Member] | International Loan [Member]
Total loans	1,097	[3]	963	[3]
Pass [Member] | Retail Loans [Member]
Total loans	3,637	[3]	3,778	[3]
Pass [Member] | Retail Loans [Member] | Residential Mortgage Loan [Member]
Total loans	1,434	[3]	1,541	[3]
Pass [Member] | Retail Loans [Member] | Consumer Loans [Member]
Total loans	2,203	[3]	2,237	[3]
Pass [Member] | Retail Loans [Member] | Consumer Loans [Member] | Home Equity [Member]
Total loans	1,600	[3]	1,662	[3]
Pass [Member] | Retail Loans [Member] | Consumer Loans [Member] | Other Consumer [Member]
Total loans	603	[3]	575	[3]
Special Mention [Member]
Total loans	1,981	[4]	2,413	[4]
Special mention loans considered pass by regulatory authorities	481		546
Special Mention [Member] | Business Loans [Member]
Total loans	1,935	[4]	2,373	[4]
Special Mention [Member] | Business Loans [Member] | Commercial Loans [Member]
Total loans	898	[4]	1,015	[4]
Special Mention [Member] | Business Loans [Member] | Real Estate Construction [Member]
Total loans	162	[4]	353	[4]
Special Mention [Member] | Business Loans [Member] | Real Estate Construction [Member] | Commercial Real Estate Business Line [Member]
Total loans	139	[1],[4]	333	[1],[4]
Special Mention [Member] | Business Loans [Member] | Real Estate Construction [Member] | Other Business Lines [Member]
Total loans	23	[2],[4]	20	[2],[4]
Special Mention [Member] | Business Loans [Member] | Commercial Mortgage [Member]
Total loans	824	[4]	880	[4]
Special Mention [Member] | Business Loans [Member] | Commercial Mortgage [Member] | Commercial Real Estate Business Line [Member]
Total loans	409	[1],[4]	372	[1],[4]
Special Mention [Member] | Business Loans [Member] | Commercial Mortgage [Member] | Other Business Lines [Member]
Total loans	415	[2],[4]	508	[2],[4]
Special Mention [Member] | Business Loans [Member] | Lease Financing Loan [Member]
Total loans	18	[4]	13	[4]
Special Mention [Member] | Business Loans [Member] | International Loan [Member]
Total loans	33	[4]	112	[4]
Special Mention [Member] | Retail Loans [Member]
Total loans	46	[4]	40	[4]
Special Mention [Member] | Retail Loans [Member] | Residential Mortgage Loan [Member]
Total loans	12	[4]	6	[4]
Special Mention [Member] | Retail Loans [Member] | Consumer Loans [Member]
Total loans	34	[4]	34	[4]
Special Mention [Member] | Retail Loans [Member] | Consumer Loans [Member] | Home Equity [Member]
Total loans	22	[4]	26	[4]
Special Mention [Member] | Retail Loans [Member] | Consumer Loans [Member] | Other Consumer [Member]
Total loans	12	[4]	8	[4]
Substandard [Member]
Total loans	1,626	[5]	2,049	[5]
Substandard [Member] | Business Loans [Member]
Total loans	1,580	[5]	2,010	[5]
Substandard [Member] | Business Loans [Member] | Commercial Loans [Member]
Total loans	655	[5]	994	[5]
Substandard [Member] | Business Loans [Member] | Real Estate Construction [Member]
Total loans	132	[5]	229	[5]
Substandard [Member] | Business Loans [Member] | Real Estate Construction [Member] | Commercial Real Estate Business Line [Member]
Total loans	103	[1],[5]	209	[1],[5]
Substandard [Member] | Business Loans [Member] | Real Estate Construction [Member] | Other Business Lines [Member]
Total loans	29	[2],[5]	20	[2],[5]
Substandard [Member] | Business Loans [Member] | Commercial Mortgage [Member]
Total loans	744	[5]	705	[5]
Substandard [Member] | Business Loans [Member] | Commercial Mortgage [Member] | Commercial Real Estate Business Line [Member]
Total loans	211	[1],[5]	280	[1],[5]
Substandard [Member] | Business Loans [Member] | Commercial Mortgage [Member] | Other Business Lines [Member]
Total loans	533	[2],[5]	425	[2],[5]
Substandard [Member] | Business Loans [Member] | Lease Financing Loan [Member]
Total loans	17	[5]	27	[5]
Substandard [Member] | Business Loans [Member] | International Loan [Member]
Total loans	32	[5]	55	[5]
Substandard [Member] | Retail Loans [Member]
Total loans	46	[5]	39	[5]
Substandard [Member] | Retail Loans [Member] | Residential Mortgage Loan [Member]
Total loans	9	[5]	17	[5]
Substandard [Member] | Retail Loans [Member] | Consumer Loans [Member]
Total loans	37	[5]	22	[5]
Substandard [Member] | Retail Loans [Member] | Consumer Loans [Member] | Home Equity [Member]
Total loans	28	[5]	11	[5]
Substandard [Member] | Retail Loans [Member] | Consumer Loans [Member] | Other Consumer [Member]
Total loans	9	[5]	11	[5]
Nonaccrual [Member]
Total loans	860	[6]	1,080	[6]
Nonaccrual [Member] | Business Loans [Member]
Total loans	778	[6]	1,007	[6]
Nonaccrual [Member] | Business Loans [Member] | Commercial Loans [Member]
Total loans	237	[6]	252	[6]
Nonaccrual [Member] | Business Loans [Member] | Real Estate Construction [Member]
Total loans	101	[6]	263	[6]
Nonaccrual [Member] | Business Loans [Member] | Real Estate Construction [Member] | Commercial Real Estate Business Line [Member]
Total loans	93	[1],[6]	259	[1],[6]
Nonaccrual [Member] | Business Loans [Member] | Real Estate Construction [Member] | Other Business Lines [Member]
Total loans	8	[2],[6]	4	[2],[6]
Nonaccrual [Member] | Business Loans [Member] | Commercial Mortgage [Member]
Total loans	427	[6]	483	[6]
Nonaccrual [Member] | Business Loans [Member] | Commercial Mortgage [Member] | Commercial Real Estate Business Line [Member]
Total loans	159	[1],[6]	181	[1],[6]
Nonaccrual [Member] | Business Loans [Member] | Commercial Mortgage [Member] | Other Business Lines [Member]
Total loans	268	[2],[6]	302	[2],[6]
Nonaccrual [Member] | Business Loans [Member] | Lease Financing Loan [Member]
Total loans	5	[6]	7	[6]
Nonaccrual [Member] | Business Loans [Member] | International Loan [Member]
Total loans	8	[6]	2	[6]
Nonaccrual [Member] | Retail Loans [Member]
Total loans	82	[6]	73	[6]
Nonaccrual [Member] | Retail Loans [Member] | Residential Mortgage Loan [Member]
Total loans	71	[6]	55	[6]
Nonaccrual [Member] | Retail Loans [Member] | Consumer Loans [Member]
Total loans	11	[6]	18	[6]
Nonaccrual [Member] | Retail Loans [Member] | Consumer Loans [Member] | Home Equity [Member]
Total loans	5	[6]	5	[6]
Nonaccrual [Member] | Retail Loans [Member] | Consumer Loans [Member] | Other Consumer [Member]
Total loans	$ 6	[6]	$ 13	[6]

[1] Primarily loans to real estate investors and developers.

[2] Primarily loans secured by owner-occupied real estate.

[3] Includes all loans not included in the categories of special mention, substandard or nonaccrual.

[4] Special mention loans are accruing loans that have potential credit weaknesses that deserve management’s close attention, such as loans to borrowers who may be experiencing financial difficulties that may result in deterioration of repayment prospects from the borrower at some future date. Included in the special mention category were $481 million and $546 million at December 31, 2011 and 2010, respectively, of loans proactively monitored by management that were considered “pass” by regulatory authorities.

[5] Substandard loans are accruing loans that have a well-defined weakness, or weaknesses, such as loans to borrowers who may be experiencing losses from operations or inadequate liquidity of a degree and duration that jeopardizes the orderly repayment of the loan. Substandard loans also are distinguished by the distinct possibility of loss in the future if these weaknesses are not corrected. PCI loans are included in the substandard category. This category is generally consistent with the "substandard" category as defined by regulatory authorities.

[6] Nonaccrual loans are loans for which the accrual of interest has been discontinued. For further information regarding nonaccrual loans, refer to Note 1. A significant majority of nonaccrual loans are generally consistent with the "substandard" category and the remainder are generally consistent with the "doubtful" category as defined by regulatory authorities.