Credit Quality and Allowance for Credit Losses (Credit Quality Indicators1) (Details) (USD $) In Millions	Jun. 30, 2011		Dec. 31, 2010		Jun. 30, 2010
Total loans	$ 39,193		$ 40,236		$ 40,602
Business Loans [Member]
Total loans	35,470		36,306
Business Loans [Member] | Commercial Loans [Member]
Total loans	22,052		22,145
Business Loans [Member] | Commercial Loans [Member] | Pass [Member]
Total loans	20,099	[1]	19,884	[1]
Business Loans [Member] | Commercial Loans [Member] | Special Mention [Member]
Total loans	900	[2]	1,015	[2]
Business Loans [Member] | Commercial Loans [Member] | Substandard [Member]
Total loans	792	[3]	994	[3]
Business Loans [Member] | Commercial Loans [Member] | Nonaccrual [Member]
Total loans	261	[4]	252	[4]
Business Loans [Member] | Real Estate Construction [Member]
Total loans	1,728		2,253
Business Loans [Member] | Real Estate Construction [Member] | Commercial Real Estate Business Line [Member]
Total loans	1,343	[5]	1,826	[5]
Business Loans [Member] | Real Estate Construction [Member] | Commercial Real Estate Business Line [Member] | Pass [Member]
Total loans	820	[1],[5]	1,025	[1],[5]
Business Loans [Member] | Real Estate Construction [Member] | Commercial Real Estate Business Line [Member] | Special Mention [Member]
Total loans	202	[2],[5]	333	[2],[5]
Business Loans [Member] | Real Estate Construction [Member] | Commercial Real Estate Business Line [Member] | Substandard [Member]
Total loans	184	[3],[5]	209	[3],[5]
Business Loans [Member] | Real Estate Construction [Member] | Commercial Real Estate Business Line [Member] | Nonaccrual [Member]
Total loans	137	[4],[5]	259	[4],[5]
Business Loans [Member] | Real Estate Construction [Member] | Other Business Lines [Member]
Total loans	385	[6]	427	[6]
Business Loans [Member] | Real Estate Construction [Member] | Other Business Lines [Member] | Pass [Member]
Total loans	341	[1],[6]	383	[1],[6]
Business Loans [Member] | Real Estate Construction [Member] | Other Business Lines [Member] | Special Mention [Member]
Total loans	24	[2],[6]	20	[2],[6]
Business Loans [Member] | Real Estate Construction [Member] | Other Business Lines [Member] | Substandard [Member]
Total loans	18	[3],[6]	20	[3],[6]
Business Loans [Member] | Real Estate Construction [Member] | Other Business Lines [Member] | Nonaccrual [Member]
Total loans	2	[4],[6]	4	[4],[6]
Business Loans [Member] | Real Estate Construction [Member] | Pass [Member]
Total loans	1,161	[1]	1,408	[1]
Business Loans [Member] | Real Estate Construction [Member] | Special Mention [Member]
Total loans	226	[2]	353	[2]
Business Loans [Member] | Real Estate Construction [Member] | Substandard [Member]
Total loans	202	[3]	229	[3]
Business Loans [Member] | Real Estate Construction [Member] | Nonaccrual [Member]
Total loans	139	[4]	263	[4]
Business Loans [Member] | Commercial Mortgage [Member]
Total loans	9,579		9,767
Business Loans [Member] | Commercial Mortgage [Member] | Commercial Real Estate Business Line [Member]
Total loans	1,930	[5]	1,937	[5]
Business Loans [Member] | Commercial Mortgage [Member] | Commercial Real Estate Business Line [Member] | Pass [Member]
Total loans	1,179	[1],[5]	1,104	[1],[5]
Business Loans [Member] | Commercial Mortgage [Member] | Commercial Real Estate Business Line [Member] | Special Mention [Member]
Total loans	328	[2],[5]	372	[2],[5]
Business Loans [Member] | Commercial Mortgage [Member] | Commercial Real Estate Business Line [Member] | Substandard [Member]
Total loans	237	[3],[5]	280	[3],[5]
Business Loans [Member] | Commercial Mortgage [Member] | Commercial Real Estate Business Line [Member] | Nonaccrual [Member]
Total loans	186	[4],[5]	181	[4],[5]
Business Loans [Member] | Commercial Mortgage [Member] | Other Business Lines [Member]
Total loans	7,649	[6]	7,830	[6]
Business Loans [Member] | Commercial Mortgage [Member] | Other Business Lines [Member] | Pass [Member]
Total loans	6,400	[1],[6]	6,595	[1],[6]
Business Loans [Member] | Commercial Mortgage [Member] | Other Business Lines [Member] | Special Mention [Member]
Total loans	504	[2],[6]	508	[2],[6]
Business Loans [Member] | Commercial Mortgage [Member] | Other Business Lines [Member] | Substandard [Member]
Total loans	476	[3],[6]	425	[3],[6]
Business Loans [Member] | Commercial Mortgage [Member] | Other Business Lines [Member] | Nonaccrual [Member]
Total loans	269	[4],[6]	302	[4],[6]
Business Loans [Member] | Commercial Mortgage [Member] | Pass [Member]
Total loans	7,579	[1]	7,699	[1]
Business Loans [Member] | Commercial Mortgage [Member] | Special Mention [Member]
Total loans	832	[2]	880	[2]
Business Loans [Member] | Commercial Mortgage [Member] | Substandard [Member]
Total loans	713	[3]	705	[3]
Business Loans [Member] | Commercial Mortgage [Member] | Nonaccrual [Member]
Total loans	455	[4]	483	[4]
Business Loans [Member] | Lease Financing Loan [Member]
Total loans	949		1,009
Business Loans [Member] | Lease Financing Loan [Member] | Pass [Member]
Total loans	912	[1]	962	[1]
Business Loans [Member] | Lease Financing Loan [Member] | Special Mention [Member]
Total loans	11	[2]	13	[2]
Business Loans [Member] | Lease Financing Loan [Member] | Substandard [Member]
Total loans	20	[3]	27	[3]
Business Loans [Member] | Lease Financing Loan [Member] | Nonaccrual [Member]
Total loans	6	[4]	7	[4]
Business Loans [Member] | International Loan [Member]
Total loans	1,162		1,132
Business Loans [Member] | International Loan [Member] | Pass [Member]
Total loans	1,061	[1]	963	[1]
Business Loans [Member] | International Loan [Member] | Special Mention [Member]
Total loans	60	[2]	112	[2]
Business Loans [Member] | International Loan [Member] | Substandard [Member]
Total loans	34	[3]	55	[3]
Business Loans [Member] | International Loan [Member] | Nonaccrual [Member]
Total loans	7	[4]	2	[4]
Business Loans [Member] | Pass [Member]
Total loans	30,812	[1]	30,916	[1]
Business Loans [Member] | Special Mention [Member]
Total loans	2,029	[2]	2,373	[2]
Business Loans [Member] | Substandard [Member]
Total loans	1,761	[3]	2,010	[3]
Business Loans [Member] | Nonaccrual [Member]
Total loans	868	[4]	1,007	[4]
Pass [Member]
Total loans	34,366	[1]	34,694	[1]
Special Mention [Member]
Total loans	2,060	[2]	2,413	[2]
Special mention loans considered pass by regulatory authorities	509		546
Substandard [Member]
Total loans	1,826	[3]	2,049	[3]
Nonaccrual [Member]
Total loans	$ 941	[4]	$ 1,080	[4]

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

[2] 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 $509 million and $546 million at June 30, 2011 and December 31, 2010, respectively, of loans proactively monitored by management that were considered "pass" by regulatory authorities.

[3] 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. This category is generally consistent with the "substandard" category as defined by regulatory authorities.

[4] Nonaccrual loans are loans for which the accrual of interest has been discontinued. For further information, refer to the Nonperforming Assets subheading in Note 1 - Summary of Significant Accounting Policies - on page 76 of the Corporation's Annual Report for the year ended December 31, 2010. This category is generally consistent with the "doubtful" category as defined by regulatory authorities.

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

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